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2016-06-07xfs: handle dquot buffer readahead in log recovery correctlyDave Chinner
commit 7d6a13f023567d573ac362502bb702eda716e654 upstream. When we do dquot readahead in log recovery, we do not use a verifier as the underlying buffer may not have dquots in it. e.g. the allocation operation hasn't yet been replayed. Hence we do not want to fail recovery because we detect an operation to be replayed has not been run yet. This problem was addressed for inodes in commit d891400 ("xfs: inode buffers may not be valid during recovery readahead") but the problem was not recognised to exist for dquots and their buffers as the dquot readahead did not have a verifier. The result of not using a verifier is that when the buffer is then next read to replay a dquot modification, the dquot buffer verifier will only be attached to the buffer if *readahead is not complete*. Hence we can read the buffer, replay the dquot changes and then add it to the delwri submission list without it having a verifier attached to it. This then generates warnings in xfs_buf_ioapply(), which catches and warns about this case. Fix this and make it handle the same readahead verifier error cases as for inode buffers by adding a new readahead verifier that has a write operation as well as a read operation that marks the buffer as not done if any corruption is detected. Also make sure we don't run readahead if the dquot buffer has been marked as cancelled by recovery. This will result in readahead either succeeding and the buffer having a valid write verifier, or readahead failing and the buffer state requiring the subsequent read to resubmit the IO with the new verifier. In either case, this will result in the buffer always ending up with a valid write verifier on it. Note: we also need to fix the inode buffer readahead error handling to mark the buffer with EIO. Brian noticed the code I copied from there wrong during review, so fix it at the same time. Add comments linking the two functions that handle readahead verifier errors together so we don't forget this behavioural link in future. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07xfs: print name of verifier if it failsEric Sandeen
commit 233135b763db7c64d07b728a9c66745fb0376275 upstream. This adds a name to each buf_ops structure, so that if a verifier fails we can print the type of verifier that failed it. Should be a slight debugging aid, I hope. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07xfs: skip stale inodes in xfs_iflush_clusterDave Chinner
commit 7d3aa7fe970791f1a674b14572a411accf2f4d4e upstream. We don't write back stale inodes so we should skip them in xfs_iflush_cluster, too. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07xfs: fix inode validity check in xfs_iflush_clusterDave Chinner
commit 51b07f30a71c27405259a0248206ed4e22adbee2 upstream. Some careless idiot(*) wrote crap code in commit 1a3e8f3 ("xfs: convert inode cache lookups to use RCU locking") back in late 2010, and so xfs_iflush_cluster checks the wrong inode for whether it is still valid under RCU protection. Fix it to lock and check the correct inode. (*) Careless-idiot: Dave Chinner <dchinner@redhat.com> Discovered-by: Brain Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07xfs: xfs_iflush_cluster fails to abort on errorDave Chinner
commit b1438f477934f5a4d5a44df26f3079a7575d5946 upstream. When a failure due to an inode buffer occurs, the error handling fails to abort the inode writeback correctly. This can result in the inode being reclaimed whilst still in the AIL, leading to use-after-free situations as well as filesystems that cannot be unmounted as the inode log items left in the AIL never get removed. Fix this by ensuring fatal errors from xfs_imap_to_bp() result in the inode flush being aborted correctly. Reported-by: Shyam Kaushik <shyam@zadarastorage.com> Diagnosed-by: Shyam Kaushik <shyam@zadarastorage.com> Tested-by: Shyam Kaushik <shyam@zadarastorage.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07xfs: Don't wrap growfs AGFL indexesDave Chinner
commit ad747e3b299671e1a53db74963cc6c5f6cdb9f6d upstream. Commit 96f859d ("libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct") allowed the freelist to use the empty slot at the end of the freelist on 64 bit systems that was not being used due to sizeof() rounding up the structure size. This has caused versions of xfs_repair prior to 4.5.0 (which also has the fix) to report this as a corruption once the filesystem has been grown. Older kernels can also have problems (seen from a whacky container/vm management environment) mounting filesystems grown on a system with a newer kernel than the vm/container it is deployed on. To avoid this problem, change the initial free list indexes not to wrap across the end of the AGFL, hence avoiding the initialisation of agf_fllast to the last index in the AGFL. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07xfs: disallow rw remount on fs with unknown ro-compat featuresEric Sandeen
commit d0a58e833931234c44e515b5b8bede32bd4e6eed upstream. Today, a kernel which refuses to mount a filesystem read-write due to unknown ro-compat features can still transition to read-write via the remount path. The old kernel is most likely none the wiser, because it's unaware of the new feature, and isn't using it. However, writing to the filesystem may well corrupt metadata related to that new feature, and moving to a newer kernel which understand the feature will have problems. Right now the only ro-compat feature we have is the free inode btree, which showed up in v3.16. It would be good to push this back to all the active stable kernels, I think, so that if anyone is using newer mkfs (which enables the finobt feature) with older kernel releases, they'll be protected. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07ext4: silence UBSAN in ext4_mb_init()Nicolai Stange
commit 935244cd54b86ca46e69bc6604d2adfb1aec2d42 upstream. Currently, in ext4_mb_init(), there's a loop like the following: do { ... offset += 1 << (sb->s_blocksize_bits - i); i++; } while (i <= sb->s_blocksize_bits + 1); Note that the updated offset is used in the loop's next iteration only. However, at the last iteration, that is at i == sb->s_blocksize_bits + 1, the shift count becomes equal to (unsigned)-1 > 31 (c.f. C99 6.5.7(3)) and UBSAN reports UBSAN: Undefined behaviour in fs/ext4/mballoc.c:2621:15 shift exponent 4294967295 is too large for 32-bit type 'int' [...] Call Trace: [<ffffffff818c4d25>] dump_stack+0xbc/0x117 [<ffffffff818c4c69>] ? _atomic_dec_and_lock+0x169/0x169 [<ffffffff819411ab>] ubsan_epilogue+0xd/0x4e [<ffffffff81941cac>] __ubsan_handle_shift_out_of_bounds+0x1fb/0x254 [<ffffffff81941ab1>] ? __ubsan_handle_load_invalid_value+0x158/0x158 [<ffffffff814b6dc1>] ? kmem_cache_alloc+0x101/0x390 [<ffffffff816fc13b>] ? ext4_mb_init+0x13b/0xfd0 [<ffffffff814293c7>] ? create_cache+0x57/0x1f0 [<ffffffff8142948a>] ? create_cache+0x11a/0x1f0 [<ffffffff821c2168>] ? mutex_lock+0x38/0x60 [<ffffffff821c23ab>] ? mutex_unlock+0x1b/0x50 [<ffffffff814c26ab>] ? put_online_mems+0x5b/0xc0 [<ffffffff81429677>] ? kmem_cache_create+0x117/0x2c0 [<ffffffff816fcc49>] ext4_mb_init+0xc49/0xfd0 [...] Observe that the mentioned shift exponent, 4294967295, equals (unsigned)-1. Unless compilers start to do some fancy transformations (which at least GCC 6.0.0 doesn't currently do), the issue is of cosmetic nature only: the such calculated value of offset is never used again. Silence UBSAN by introducing another variable, offset_incr, holding the next increment to apply to offset and adjust that one by right shifting it by one position per loop iteration. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=114701 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=112161 Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07ext4: address UBSAN warning in mb_find_order_for_block()Nicolai Stange
commit b5cb316cdf3a3f5f6125412b0f6065185240cfdc upstream. Currently, in mb_find_order_for_block(), there's a loop like the following: while (order <= e4b->bd_blkbits + 1) { ... bb += 1 << (e4b->bd_blkbits - order); } Note that the updated bb is used in the loop's next iteration only. However, at the last iteration, that is at order == e4b->bd_blkbits + 1, the shift count becomes negative (c.f. C99 6.5.7(3)) and UBSAN reports UBSAN: Undefined behaviour in fs/ext4/mballoc.c:1281:11 shift exponent -1 is negative [...] Call Trace: [<ffffffff818c4d35>] dump_stack+0xbc/0x117 [<ffffffff818c4c79>] ? _atomic_dec_and_lock+0x169/0x169 [<ffffffff819411bb>] ubsan_epilogue+0xd/0x4e [<ffffffff81941cbc>] __ubsan_handle_shift_out_of_bounds+0x1fb/0x254 [<ffffffff81941ac1>] ? __ubsan_handle_load_invalid_value+0x158/0x158 [<ffffffff816e93a0>] ? ext4_mb_generate_from_pa+0x590/0x590 [<ffffffff816502c8>] ? ext4_read_block_bitmap_nowait+0x598/0xe80 [<ffffffff816e7b7e>] mb_find_order_for_block+0x1ce/0x240 [...] Unless compilers start to do some fancy transformations (which at least GCC 6.0.0 doesn't currently do), the issue is of cosmetic nature only: the such calculated value of bb is never used again. Silence UBSAN by introducing another variable, bb_incr, holding the next increment to apply to bb and adjust that one by right shifting it by one position per loop iteration. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=114701 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=112161 Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07ext4: fix oops on corrupted filesystemJan Kara
commit 74177f55b70e2f2be770dd28684dd6d17106a4ba upstream. When filesystem is corrupted in the right way, it can happen ext4_mark_iloc_dirty() in ext4_orphan_add() returns error and we subsequently remove inode from the in-memory orphan list. However this deletion is done with list_del(&EXT4_I(inode)->i_orphan) and thus we leave i_orphan list_head with a stale content. Later we can look at this content causing list corruption, oops, or other issues. The reported trace looked like: WARNING: CPU: 0 PID: 46 at lib/list_debug.c:53 __list_del_entry+0x6b/0x100() list_del corruption, 0000000061c1d6e0->next is LIST_POISON1 0000000000100100) CPU: 0 PID: 46 Comm: ext4.exe Not tainted 4.1.0-rc4+ #250 Stack: 60462947 62219960 602ede24 62219960 602ede24 603ca293 622198f0 602f02eb 62219950 6002c12c 62219900 601b4d6b Call Trace: [<6005769c>] ? vprintk_emit+0x2dc/0x5c0 [<602ede24>] ? printk+0x0/0x94 [<600190bc>] show_stack+0xdc/0x1a0 [<602ede24>] ? printk+0x0/0x94 [<602ede24>] ? printk+0x0/0x94 [<602f02eb>] dump_stack+0x2a/0x2c [<6002c12c>] warn_slowpath_common+0x9c/0xf0 [<601b4d6b>] ? __list_del_entry+0x6b/0x100 [<6002c254>] warn_slowpath_fmt+0x94/0xa0 [<602f4d09>] ? __mutex_lock_slowpath+0x239/0x3a0 [<6002c1c0>] ? warn_slowpath_fmt+0x0/0xa0 [<60023ebf>] ? set_signals+0x3f/0x50 [<600a205a>] ? kmem_cache_free+0x10a/0x180 [<602f4e88>] ? mutex_lock+0x18/0x30 [<601b4d6b>] __list_del_entry+0x6b/0x100 [<601177ec>] ext4_orphan_del+0x22c/0x2f0 [<6012f27c>] ? __ext4_journal_start_sb+0x2c/0xa0 [<6010b973>] ? ext4_truncate+0x383/0x390 [<6010bc8b>] ext4_write_begin+0x30b/0x4b0 [<6001bb50>] ? copy_from_user+0x0/0xb0 [<601aa840>] ? iov_iter_fault_in_readable+0xa0/0xc0 [<60072c4f>] generic_perform_write+0xaf/0x1e0 [<600c4166>] ? file_update_time+0x46/0x110 [<60072f0f>] __generic_file_write_iter+0x18f/0x1b0 [<6010030f>] ext4_file_write_iter+0x15f/0x470 [<60094e10>] ? unlink_file_vma+0x0/0x70 [<6009b180>] ? unlink_anon_vmas+0x0/0x260 [<6008f169>] ? free_pgtables+0xb9/0x100 [<600a6030>] __vfs_write+0xb0/0x130 [<600a61d5>] vfs_write+0xa5/0x170 [<600a63d6>] SyS_write+0x56/0xe0 [<6029fcb0>] ? __libc_waitpid+0x0/0xa0 [<6001b698>] handle_syscall+0x68/0x90 [<6002633d>] userspace+0x4fd/0x600 [<6002274f>] ? save_registers+0x1f/0x40 [<60028bd7>] ? arch_prctl+0x177/0x1b0 [<60017bd5>] fork_handler+0x85/0x90 Fix the problem by using list_del_init() as we always should with i_orphan list. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07ext4: clean up error handling when orphan list is corruptedTheodore Ts'o
commit 7827a7f6ebfcb7f388dc47fddd48567a314701ba upstream. Instead of just printing warning messages, if the orphan list is corrupted, declare the file system is corrupted. If there are any reserved inodes in the orphaned inode list, declare the file system corrupted and stop right away to avoid doing more potential damage to the file system. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07ext4: fix hang when processing corrupted orphaned inode listTheodore Ts'o
commit c9eb13a9105e2e418f72e46a2b6da3f49e696902 upstream. If the orphaned inode list contains inode #5, ext4_iget() returns a bad inode (since the bootloader inode should never be referenced directly). Because of the bad inode, we end up processing the inode repeatedly and this hangs the machine. This can be reproduced via: mke2fs -t ext4 /tmp/foo.img 100 debugfs -w -R "ssv last_orphan 5" /tmp/foo.img mount -o loop /tmp/foo.img /mnt (But don't do this if you are using an unpatched kernel if you care about the system staying functional. :-) This bug was found by the port of American Fuzzy Lop into the kernel to find file system problems[1]. (Since it *only* happens if inode #5 shows up on the orphan list --- 3, 7, 8, etc. won't do it, it's not surprising that AFL needed two hours before it found it.) [1] http://events.linuxfoundation.org/sites/events/files/slides/AFL%20filesystem%20fuzzing%2C%20Vault%202016_0.pdf Reported by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07pipe: limit the per-user amount of pages allocated in pipesWilly Tarreau
commit 759c01142a5d0f364a462346168a56de28a80f52 upstream. On no-so-small systems, it is possible for a single process to cause an OOM condition by filling large pipes with data that are never read. A typical process filling 4000 pipes with 1 MB of data will use 4 GB of memory. On small systems it may be tricky to set the pipe max size to prevent this from happening. This patch makes it possible to enforce a per-user soft limit above which new pipes will be limited to a single page, effectively limiting them to 4 kB each, as well as a hard limit above which no new pipes may be created for this user. This has the effect of protecting the system against memory abuse without hurting other users, and still allowing pipes to work correctly though with less data at once. The limit are controlled by two new sysctls : pipe-user-pages-soft, and pipe-user-pages-hard. Both may be disabled by setting them to zero. The default soft limit allows the default number of FDs per process (1024) to create pipes of the default size (64kB), thus reaching a limit of 64MB before starting to create only smaller pipes. With 256 processes limited to 1024 FDs each, this results in 1024*64kB + (256*1024 - 1024) * 4kB = 1084 MB of memory allocated for a user. The hard limit is disabled by default to avoid breaking existing applications that make intensive use of pipes (eg: for splicing). Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Moritz Muehlenhoff <moritz@wikimedia.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-07affs: fix remount failure when there are no options changedMikulas Patocka
commit 01d6e08711bf90bc4d7ead14a93a0cbd73b1896a upstream. Commit c8f33d0bec99 ("affs: kstrdup() memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: c8f33d0bec99 ("affs: kstrdup() memory handling") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01hpfs: implement the show_options methodMikulas Patocka
commit 037369b872940cd923835a0a589763180c4a36bc upstream. The HPFS filesystem used generic_show_options to produce string that is displayed in /proc/mounts. However, there is a problem that the options may disappear after remount. If we mount the filesystem with option1 and then remount it with option2, /proc/mounts should show both option1 and option2, however it only shows option2 because the whole option string is replaced with replace_mount_options in hpfs_remount_fs. To fix this bug, implement the hpfs_show_options function that prints options that are currently selected. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01hpfs: fix remount failure when there are no options changedMikulas Patocka
commit 44d51706b4685f965cd32acde3fe0fcc1e6198e8 upstream. Commit ce657611baf9 ("hpfs: kstrdup() out of memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: ce657611baf9 ("hpfs: kstrdup() out of memory handling") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01fs/cifs: correctly to anonymous authentication for the NTLM(v2) authenticationStefan Metzmacher
commit 1a967d6c9b39c226be1b45f13acd4d8a5ab3dc44 upstream. Only server which map unknown users to guest will allow access using a non-null NTLMv2_Response. For Samba it's the "map to guest = bad user" option. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913 Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01fs/cifs: correctly to anonymous authentication for the NTLM(v1) authenticationStefan Metzmacher
commit 777f69b8d26bf35ade4a76b08f203c11e048365d upstream. Only server which map unknown users to guest will allow access using a non-null NTChallengeResponse. For Samba it's the "map to guest = bad user" option. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913 Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01fs/cifs: correctly to anonymous authentication for the LANMAN authenticationStefan Metzmacher
commit fa8f3a354bb775ec586e4475bcb07f7dece97e0c upstream. Only server which map unknown users to guest will allow access using a non-null LMChallengeResponse. For Samba it's the "map to guest = bad user" option. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913 Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01fs/cifs: correctly to anonymous authentication via NTLMSSPStefan Metzmacher
commit cfda35d98298131bf38fbad3ce4cd5ecb3cf18db upstream. See [MS-NLMP] 3.2.5.1.2 Server Receives an AUTHENTICATE_MESSAGE from the Client: ... Set NullSession to FALSE If (AUTHENTICATE_MESSAGE.UserNameLen == 0 AND AUTHENTICATE_MESSAGE.NtChallengeResponse.Length == 0 AND (AUTHENTICATE_MESSAGE.LmChallengeResponse == Z(1) OR AUTHENTICATE_MESSAGE.LmChallengeResponse.Length == 0)) -- Special case: client requested anonymous authentication Set NullSession to TRUE ... Only server which map unknown users to guest will allow access using a non-null NTChallengeResponse. For Samba it's the "map to guest = bad user" option. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913 Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01remove directory incorrectly tries to set delete on close on non-empty ↵Steve French
directories commit 897fba1172d637d344f009d700f7eb8a1fa262f1 upstream. Wrong return code was being returned on SMB3 rmdir of non-empty directory. For SMB3 (unlike for cifs), we attempt to delete a directory by set of delete on close flag on the open. Windows clients set this flag via a set info (SET_FILE_DISPOSITION to set this flag) which properly checks if the directory is empty. With this patch on smb3 mounts we correctly return "DIRECTORY NOT EMPTY" on attempts to remove a non-empty directory. Signed-off-by: Steve French <steve.french@primarydata.com> Acked-by: Sachin Prabhu <sprabhu@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01ext4: iterate over buffer heads correctly in move_extent_per_page()Eryu Guan
commit 6ffe77bad545f4a7c8edd2a4ee797ccfcd894ab4 upstream. In commit bcff24887d00 ("ext4: don't read blocks from disk after extents being swapped") bh is not updated correctly in the for loop and wrong data has been written to disk. generic/324 catches this on sub-page block size ext4. Fixes: bcff24887d00 ("ext4: don't read blocks from disk after extentsbeing swapped") Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01Btrfs: don't use src fd for printkJosef Bacik
commit c79b4713304f812d3d6c95826fc3e5fc2c0b0c14 upstream. The fd we pass in may not be on a btrfs file system, so don't try to do BTRFS_I() on it. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18get_rock_ridge_filename(): handle malformed NM entriesAl Viro
commit 99d825822eade8d827a1817357cbf3f889a552d6 upstream. Payloads of NM entries are not supposed to contain NUL. When we run into such, only the part prior to the first NUL goes into the concatenation (i.e. the directory entry name being encoded by a bunch of NM entries). We do stop when the amount collected so far + the claimed amount in the current NM entry exceed 254. So far, so good, but what we return as the total length is the sum of *claimed* sizes, not the actual amount collected. And that can grow pretty large - not unlimited, since you'd need to put CE entries in between to be able to get more than the maximum that could be contained in one isofs directory entry / continuation chunk and we are stop once we'd encountered 32 CEs, but you can get about 8Kb easily. And that's what will be passed to readdir callback as the name length. 8Kb __copy_to_user() from a buffer allocated by __get_free_page() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18atomic_open(): fix the handling of create_errorAl Viro
commit 10c64cea04d3c75c306b3f990586ffb343b63287 upstream. * if we have a hashed negative dentry and either CREAT|EXCL on r/o filesystem, or CREAT|TRUNC on r/o filesystem, or CREAT|EXCL with failing may_o_create(), we should fail with EROFS or the error may_o_create() has returned, but not ENOENT. Which is what the current code ends up returning. * if we have CREAT|TRUNC hitting a regular file on a read-only filesystem, we can't fail with EROFS here. At the very least, not until we'd done follow_managed() - we might have a writable file (or a device, for that matter) bound on top of that one. Moreover, the code downstream will see that O_TRUNC and attempt to grab the write access (*after* following possible mount), so if we really should fail with EROFS, it will happen. No need to do that inside atomic_open(). The real logics is much simpler than what the current code is trying to do - if we decided to go for simple lookup, ended up with a negative dentry *and* had create_error set, fail with create_error. No matter whether we'd got that negative dentry from lookup_real() or had found it in dcache. Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18vfs: rename: check backing inode being equalMiklos Szeredi
commit 9409e22acdfc9153f88d9b1ed2bd2a5b34d2d3ca upstream. If a file is renamed to a hardlink of itself POSIX specifies that rename(2) should do nothing and return success. This condition is checked in vfs_rename(). However it won't detect hard links on overlayfs where these are given separate inodes on the overlayfs layer. Overlayfs itself detects this condition and returns success without doing anything, but then vfs_rename() will proceed as if this was a successful rename (detach_mounts(), d_move()). The correct thing to do is to detect this condition before even calling into overlayfs. This patch does this by calling vfs_select_inode() to get the underlying inodes. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18vfs: add vfs_select_inode() helperMiklos Szeredi
commit 54d5ca871e72f2bb172ec9323497f01cd5091ec7 upstream. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18ocfs2: fix posix_acl_create deadlockJunxiao Bi
commit c25a1e0671fbca7b2c0d0757d533bd2650d6dc0c upstream. Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") refactored code to use posix_acl_create. The problem with this function is that it is not mindful of the cluster wide inode lock making it unsuitable for use with ocfs2 inode creation with ACLs. For example, when used in ocfs2_mknod, this function can cause deadlock as follows. The parent dir inode lock is taken when calling posix_acl_create -> get_acl -> ocfs2_iop_get_acl which takes the inode lock again. This can cause deadlock if there is a blocked remote lock request waiting for the lock to be downconverted. And same deadlock happened in ocfs2_reflink. This fix is to revert back using ocfs2_init_acl. Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hangJunxiao Bi
commit 5ee0fbd50fdf1c1329de8bee35ea9d7c6a81a2e0 upstream. Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") introduced this issue. ocfs2_setattr called by chmod command holds cluster wide inode lock when calling posix_acl_chmod. This latter function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl. These two are also called directly from vfs layer for getfacl/setfacl commands and therefore acquire the cluster wide inode lock. If a remote conversion request comes after the first inode lock in ocfs2_setattr, OCFS2_LOCK_BLOCKED will be set. And this will cause the second call to inode lock from the ocfs2_iop_get_acl() to block indefinetly. The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which does not call back into the filesystem. Therefore, we restore ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that instead. Fixes: 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-11propogate_mnt: Handle the first propogated copy being a slaveEric W. Biederman
commit 5ec0811d30378ae104f250bfc9b3640242d81e3f upstream. When the first propgated copy was a slave the following oops would result: > BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 > IP: [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0 > PGD bacd4067 PUD bac66067 PMD 0 > Oops: 0000 [#1] SMP > Modules linked in: > CPU: 1 PID: 824 Comm: mount Not tainted 4.6.0-rc5userns+ #1523 > Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 > task: ffff8800bb0a8000 ti: ffff8800bac3c000 task.ti: ffff8800bac3c000 > RIP: 0010:[<ffffffff811fba4e>] [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0 > RSP: 0018:ffff8800bac3fd38 EFLAGS: 00010283 > RAX: 0000000000000000 RBX: ffff8800bb77ec00 RCX: 0000000000000010 > RDX: 0000000000000000 RSI: ffff8800bb58c000 RDI: ffff8800bb58c480 > RBP: ffff8800bac3fd48 R08: 0000000000000001 R09: 0000000000000000 > R10: 0000000000001ca1 R11: 0000000000001c9d R12: 0000000000000000 > R13: ffff8800ba713800 R14: ffff8800bac3fda0 R15: ffff8800bb77ec00 > FS: 00007f3c0cd9b7e0(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000010 CR3: 00000000bb79d000 CR4: 00000000000006e0 > Stack: > ffff8800bb77ec00 0000000000000000 ffff8800bac3fd88 ffffffff811fbf85 > ffff8800bac3fd98 ffff8800bb77f080 ffff8800ba713800 ffff8800bb262b40 > 0000000000000000 0000000000000000 ffff8800bac3fdd8 ffffffff811f1da0 > Call Trace: > [<ffffffff811fbf85>] propagate_mnt+0x105/0x140 > [<ffffffff811f1da0>] attach_recursive_mnt+0x120/0x1e0 > [<ffffffff811f1ec3>] graft_tree+0x63/0x70 > [<ffffffff811f1f6b>] do_add_mount+0x9b/0x100 > [<ffffffff811f2c1a>] do_mount+0x2aa/0xdf0 > [<ffffffff8117efbe>] ? strndup_user+0x4e/0x70 > [<ffffffff811f3a45>] SyS_mount+0x75/0xc0 > [<ffffffff8100242b>] do_syscall_64+0x4b/0xa0 > [<ffffffff81988f3c>] entry_SYSCALL64_slow_path+0x25/0x25 > Code: 00 00 75 ec 48 89 0d 02 22 22 01 8b 89 10 01 00 00 48 89 05 fd 21 22 01 39 8e 10 01 00 00 0f 84 e0 00 00 00 48 8b 80 d8 00 00 00 <48> 8b 50 10 48 89 05 df 21 22 01 48 89 15 d0 21 22 01 8b 53 30 > RIP [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0 > RSP <ffff8800bac3fd38> > CR2: 0000000000000010 > ---[ end trace 2725ecd95164f217 ]--- This oops happens with the namespace_sem held and can be triggered by non-root users. An all around not pleasant experience. To avoid this scenario when finding the appropriate source mount to copy stop the walk up the mnt_master chain when the first source mount is encountered. Further rewrite the walk up the last_source mnt_master chain so that it is clear what is going on. The reason why the first source mount is special is that it it's mnt_parent is not a mount in the dest_mnt propagation tree, and as such termination conditions based up on the dest_mnt mount propgation tree do not make sense. To avoid other kinds of confusion last_dest is not changed when computing last_source. last_dest is only used once in propagate_one and that is above the point of the code being modified, so changing the global variable is meaningless and confusing. fixes: f2ebb3a921c1ca1e2ddd9242e95a1989a50c4c68 ("smarter propagate_mnt()") Reported-by: Tycho Andersen <tycho.andersen@canonical.com> Reviewed-by: Seth Forshee <seth.forshee@canonical.com> Tested-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-11fs/pnode.c: treat zero mnt_group_id-s as unequalMaxim Patlasov
commit 7ae8fd0351f912b075149a1e03a017be8b903b9a upstream. propagate_one(m) calculates "type" argument for copy_tree() like this: > if (m->mnt_group_id == last_dest->mnt_group_id) { > type = CL_MAKE_SHARED; > } else { > type = CL_SLAVE; > if (IS_MNT_SHARED(m)) > type |= CL_MAKE_SHARED; > } The "type" argument then governs clone_mnt() behavior with respect to flags and mnt_master of new mount. When we iterate through a slave group, it is possible that both current "m" and "last_dest" are not shared (although, both are slaves, i.e. have non-NULL mnt_master-s). Then the comparison above erroneously makes new mount shared and sets its mnt_master to last_source->mnt_master. The patch fixes the problem by handling zero mnt_group_id-s as though they are unequal. The similar problem exists in the implementation of "else" clause above when we have to ascend upward in the master/slave tree by calling: > last_source = last_source->mnt_master; > last_dest = last_source->mnt_parent; proper number of times. The last step is governed by "n->mnt_group_id != last_dest->mnt_group_id" condition that may lie if both are zero. The patch fixes this case in the same way as the former one. [AV: don't open-code an obvious helper...] Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-11proc: prevent accessing /proc/<PID>/environ until it's readyMathias Krause
commit 8148a73c9901a8794a50f950083c00ccf97d43b3 upstream. If /proc/<PID>/environ gets read before the envp[] array is fully set up in create_{aout,elf,elf_fdpic,flat}_tables(), we might end up trying to read more bytes than are actually written, as env_start will already be set but env_end will still be zero, making the range calculation underflow, allowing to read beyond the end of what has been written. Fix this as it is done for /proc/<PID>/cmdline by testing env_end for zero. It is, apparently, intentionally set last in create_*_tables(). This bug was found by the PaX size_overflow plugin that detected the arithmetic underflow of 'this_len = env_end - (env_start + src)' when env_end is still zero. The expected consequence is that userland trying to access /proc/<PID>/environ of a not yet fully set up process may get inconsistent data as we're in the middle of copying in the environment variables. Fixes: https://forums.grsecurity.net/viewtopic.php?f=3&t=4363 Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=116461 Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: Pax Team <pageexec@freemail.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jarod Wilson <jarod@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04ext4: fix races of writeback with punch hole and zero rangeJan Kara
commit 011278485ecc3cd2a3954b5d4c73101d919bf1fa upstream. When doing delayed allocation, update of on-disk inode size is postponed until IO submission time. However hole punch or zero range fallocate calls can end up discarding the tail page cache page and thus on-disk inode size would never be properly updated. Make sure the on-disk inode size is updated before truncating page cache. Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04ext4: fix races between buffered IO and collapse / insert rangeJan Kara
commit 32ebffd3bbb4162da5ff88f9a35dd32d0a28ea70 upstream. Current code implementing FALLOC_FL_COLLAPSE_RANGE and FALLOC_FL_INSERT_RANGE is prone to races with buffered writes and page faults. If buffered write or write via mmap manages to squeeze between filemap_write_and_wait_range() and truncate_pagecache() in the fallocate implementations, the written data is simply discarded by truncate_pagecache() although it should have been shifted. Fix the problem by moving filemap_write_and_wait_range() call inside i_mutex and i_mmap_sem. That way we are protected against races with both buffered writes and page faults. Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04ext4: move unlocked dio protection from ext4_alloc_file_blocks()Jan Kara
commit 17048e8a083fec7ad841d88ef0812707fbc7e39f upstream. Currently ext4_alloc_file_blocks() was handling protection against unlocked DIO. However we now need to sometimes call it under i_mmap_sem and sometimes not and DIO protection ranks above it (although strictly speaking this cannot currently create any deadlocks). Also ext4_zero_range() was actually getting & releasing unlocked DIO protection twice in some cases. Luckily it didn't introduce any real bug but it was a land mine waiting to be stepped on. So move DIO protection out from ext4_alloc_file_blocks() into the two callsites. Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04ext4: fix races between page faults and hole punchingJan Kara
commit ea3d7209ca01da209cda6f0dea8be9cc4b7a933b upstream. Currently, page faults and hole punching are completely unsynchronized. This can result in page fault faulting in a page into a range that we are punching after truncate_pagecache_range() has been called and thus we can end up with a page mapped to disk blocks that will be shortly freed. Filesystem corruption will shortly follow. Note that the same race is avoided for truncate by checking page fault offset against i_size but there isn't similar mechanism available for punching holes. Fix the problem by creating new rw semaphore i_mmap_sem in inode and grab it for writing over truncate, hole punching, and other functions removing blocks from extent tree and for read over page faults. We cannot easily use i_data_sem for this since that ranks below transaction start and we need something ranking above it so that it can be held over the whole truncate / hole punching operation. Also remove various workarounds we had in the code to reduce race window when page fault could have created pages with stale mapping information. Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04ext4: fix NULL pointer dereference in ext4_mark_inode_dirty()Eryu Guan
commit 5e1021f2b6dff1a86a468a1424d59faae2bc63c1 upstream. ext4_reserve_inode_write() in ext4_mark_inode_dirty() could fail on error (e.g. EIO) and iloc.bh can be NULL in this case. But the error is ignored in the following "if" condition and ext4_expand_extra_isize() might be called with NULL iloc.bh set, which triggers NULL pointer dereference. This is uncovered by commit 8b4953e13f4c ("ext4: reserve code points for the project quota feature"), which enlarges the ext4_inode size, and run the following script on new kernel but with old mke2fs: #/bin/bash mnt=/mnt/ext4 devname=ext4-error dev=/dev/mapper/$devname fsimg=/home/fs.img trap cleanup 0 1 2 3 9 15 cleanup() { umount $mnt >/dev/null 2>&1 dmsetup remove $devname losetup -d $backend_dev rm -f $fsimg exit 0 } rm -f $fsimg fallocate -l 1g $fsimg backend_dev=`losetup -f --show $fsimg` devsize=`blockdev --getsz $backend_dev` good_tab="0 $devsize linear $backend_dev 0" error_tab="0 $devsize error $backend_dev 0" dmsetup create $devname --table "$good_tab" mkfs -t ext4 $dev mount -t ext4 -o errors=continue,strictatime $dev $mnt dmsetup load $devname --table "$error_tab" && dmsetup resume $devname echo 3 > /proc/sys/vm/drop_caches ls -l $mnt exit 0 [ Patch changed to simplify the function a tiny bit. -- Ted ] Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04numa: fix /proc/<pid>/numa_maps for THPGerald Schaefer
commit 28093f9f34cedeaea0f481c58446d9dac6dd620f upstream. In gather_pte_stats() a THP pmd is cast into a pte, which is wrong because the layouts may differ depending on the architecture. On s390 this will lead to inaccurate numa_maps accounting in /proc because of misguided pte_present() and pte_dirty() checks on the fake pte. On other architectures pte_present() and pte_dirty() may work by chance, but there may be an issue with direct-access (dax) mappings w/o underlying struct pages when HAVE_PTE_SPECIAL is set and THP is available. In vm_normal_page() the fake pte will be checked with pte_special() and because there is no "special" bit in a pmd, this will always return false and the VM_PFNMAP | VM_MIXEDMAP checking will be skipped. On dax mappings w/o struct pages, an invalid struct page pointer would then be returned that can crash the kernel. This patch fixes the numa_maps THP handling by introducing new "_pmd" variants of the can_gather_numa_stats() and vm_normal_page() functions. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04debugfs: Make automount point inodes permanently emptySeth Forshee
commit 87243deb88671f70def4c52dfa7ca7830707bd31 upstream. Starting with 4.1 the tracing subsystem has its own filesystem which is automounted in the tracing subdirectory of debugfs. Prior to this debugfs could be bind mounted in a cloned mount namespace, but if tracefs has been mounted under debugfs this now fails because there is a locked child mount. This creates a regression for container software which bind mounts debugfs to satisfy the assumption of some userspace software. In other pseudo filesystems such as proc and sysfs we're already creating mountpoints like this in such a way that no dirents can be created in the directories, allowing them to be exceptions to some MNT_LOCKED tests. In fact we're already do this for the tracefs mountpoint in sysfs. Do the same in debugfs_create_automount(), since the intention here is clearly to create a mountpoint. This fixes the regression, as locked child mounts on permanently empty directories do not cause a bind mount to fail. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20Btrfs: fix file/data loss caused by fsync after rename and new inodeFilipe Manana
commit 56f23fdbb600e6087db7b009775b95ce07cc3195 upstream. If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20ext4: ignore quota mount options if the quota feature is enabledTheodore Ts'o
commit c325a67c72903e1cc30e990a15ce745bda0dbfde upstream. Previously, ext4 would fail the mount if the file system had the quota feature enabled and quota mount options (used for the older quota setups) were present. This broke xfstests, since xfs silently ignores the usrquote and grpquota mount options if they are specified. This commit changes things so that we are consistent with xfs; having the mount options specified is harmless, so no sense break users by forbidding them. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20ext4: add lockdep annotations for i_data_semTheodore Ts'o
commit daf647d2dd58cec59570d7698a45b98e580f2076 upstream. With the internal Quota feature, mke2fs creates empty quota inodes and quota usage tracking is enabled as soon as the file system is mounted. Since quotacheck is no longer preallocating all of the blocks in the quota inode that are likely needed to be written to, we are now seeing a lockdep false positive caused by needing to allocate a quota block from inside ext4_map_blocks(), while holding i_data_sem for a data inode. This results in this complaint: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->i_data_sem); lock(&s->s_dquot.dqio_mutex); lock(&ei->i_data_sem); lock(&s->s_dquot.dqio_mutex); Google-Bug-Id: 27907753 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20btrfs: fix crash/invalid memory access on fsync when using overlayfsFilipe Manana
commit de17e793b104d690e1d007dfc5cb6b4f649598ca upstream. If the lower or upper directory of an overlayfs mount belong to a btrfs file system and we fsync the file through the overlayfs' merged directory we ended up accessing an inode that didn't belong to btrfs as if it were a btrfs inode at btrfs_sync_file() resulting in a crash like the following: [ 7782.588845] BUG: unable to handle kernel NULL pointer dereference at 0000000000000544 [ 7782.590624] IP: [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs] [ 7782.591931] PGD 4d954067 PUD 1e878067 PMD 0 [ 7782.592016] Oops: 0002 [#6] PREEMPT SMP DEBUG_PAGEALLOC [ 7782.592016] Modules linked in: btrfs overlay ppdev crc32c_generic evdev xor raid6_pq psmouse pcspkr sg serio_raw acpi_cpufreq parport_pc parport tpm_tis i2c_piix4 tpm i2c_core processor button loop autofs4 ext4 crc16 mbcache jbd2 sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs] [ 7782.592016] CPU: 10 PID: 16437 Comm: xfs_io Tainted: G D 4.5.0-rc6-btrfs-next-26+ #1 [ 7782.592016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 7782.592016] task: ffff88001b8d40c0 ti: ffff880137488000 task.ti: ffff880137488000 [ 7782.592016] RIP: 0010:[<ffffffffa030b7ab>] [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs] [ 7782.592016] RSP: 0018:ffff88013748be40 EFLAGS: 00010286 [ 7782.592016] RAX: 0000000080000000 RBX: ffff880133b30c88 RCX: 0000000000000001 [ 7782.592016] RDX: 0000000000000001 RSI: ffffffff8148fec0 RDI: 00000000ffffffff [ 7782.592016] RBP: ffff88013748bec0 R08: 0000000000000001 R09: 0000000000000000 [ 7782.624248] R10: ffff88013748be40 R11: 0000000000000246 R12: 0000000000000000 [ 7782.624248] R13: 0000000000000000 R14: 00000000009305a0 R15: ffff880015e3be40 [ 7782.624248] FS: 00007fa83b9cb700(0000) GS:ffff88023ed40000(0000) knlGS:0000000000000000 [ 7782.624248] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7782.624248] CR2: 0000000000000544 CR3: 00000001fa652000 CR4: 00000000000006e0 [ 7782.624248] Stack: [ 7782.624248] ffffffff8108b5cc ffff88013748bec0 0000000000000246 ffff8800b005ded0 [ 7782.624248] ffff880133b30d60 8000000000000000 7fffffffffffffff 0000000000000246 [ 7782.624248] 0000000000000246 ffffffff81074f9b ffffffff8104357c ffff880015e3be40 [ 7782.624248] Call Trace: [ 7782.624248] [<ffffffff8108b5cc>] ? arch_local_irq_save+0x9/0xc [ 7782.624248] [<ffffffff81074f9b>] ? ___might_sleep+0xce/0x217 [ 7782.624248] [<ffffffff8104357c>] ? __do_page_fault+0x3c0/0x43a [ 7782.624248] [<ffffffff811a2351>] vfs_fsync_range+0x8c/0x9e [ 7782.624248] [<ffffffff811a237f>] vfs_fsync+0x1c/0x1e [ 7782.624248] [<ffffffff811a24d6>] do_fsync+0x31/0x4a [ 7782.624248] [<ffffffff811a2700>] SyS_fsync+0x10/0x14 [ 7782.624248] [<ffffffff81493617>] entry_SYSCALL_64_fastpath+0x12/0x6b [ 7782.624248] Code: 85 c0 0f 85 e2 02 00 00 48 8b 45 b0 31 f6 4c 29 e8 48 ff c0 48 89 45 a8 48 8d 83 d8 00 00 00 48 89 c7 48 89 45 a0 e8 fc 43 18 e1 <f0> 41 ff 84 24 44 05 00 00 48 8b 83 58 ff ff ff 48 c1 e8 07 83 [ 7782.624248] RIP [<ffffffffa030b7ab>] btrfs_sync_file+0x11b/0x3e9 [btrfs] [ 7782.624248] RSP <ffff88013748be40> [ 7782.624248] CR2: 0000000000000544 [ 7782.661994] ---[ end trace 721e14960eb939bc ]--- This started happening since commit 4bacc9c9234 (overlayfs: Make f_path always point to the overlay and f_inode to the underlay) and even though after this change we could still access the btrfs inode through struct file->f_mapping->host or struct file->f_inode, we would end up resulting in more similar issues later on at check_parent_dirs_for_sync() because the dentry we got (from struct file->f_path.dentry) was from overlayfs and not from btrfs, that is, we had no way of getting the dentry that belonged to btrfs (we always got the dentry that belonged to overlayfs). The new patch from Miklos Szeredi, titled "vfs: add file_dentry()" and recently submitted to linux-fsdevel, adds a file_dentry() API that allows us to get the btrfs dentry from the input file and therefore being able to fsync when the upper and lower directories belong to btrfs filesystems. This issue has been reported several times by users in the mailing list and bugzilla. A test case for xfstests is being submitted as well. Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=101951 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109791 Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20nfs: use file_dentry()Miklos Szeredi
commit be62a1a8fd116f5cd9e53726601f970e16e17558 upstream. NFS may be used as lower layer of overlayfs and accessing f_path.dentry can lead to a crash. Fix by replacing direct access of file->f_path.dentry with the file_dentry() accessor, which will always return a native object. Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20fs: add file_dentry()Miklos Szeredi
commit d101a125954eae1d397adda94ca6319485a50493 upstream. This series fixes bugs in nfs and ext4 due to 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay"). Regular files opened on overlayfs will result in the file being opened on the underlying filesystem, while f_path points to the overlayfs mount/dentry. This confuses filesystems which get the dentry from struct file and assume it's theirs. Add a new helper, file_dentry() [*], to get the filesystem's own dentry from the file. This checks file->f_path.dentry->d_flags against DCACHE_OP_REAL, and returns file->f_path.dentry if DCACHE_OP_REAL is not set (this is the common, non-overlayfs case). In the uncommon case it will call into overlayfs's ->d_real() to get the underlying dentry, matching file_inode(file). The reason we need to check against the inode is that if the file is copied up while being open, d_real() would return the upper dentry, while the open file comes from the lower dentry. [*] If possible, it's better simply to use file_inode() instead. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12ocfs2/dlm: fix BUG in dlm_move_lockres_to_recovery_listJoseph Qi
commit be12b299a83fc807bbaccd2bcb8ec50cbb0cb55c upstream. When master handles convert request, it queues ast first and then returns status. This may happen that the ast is sent before the request status because the above two messages are sent by two threads. And right after the ast is sent, if master down, it may trigger BUG in dlm_move_lockres_to_recovery_list in the requested node because ast handler moves it to grant list without clear lock->convert_pending. So remove BUG_ON statement and check if the ast is processed in dlmconvert_remote. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reported-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Tariq Saeed <tariq.x.saeed@oracle.com> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12ocfs2/dlm: fix race between convert and recoveryJoseph Qi
commit ac7cf246dfdbec3d8fed296c7bf30e16f5099dac upstream. There is a race window between dlmconvert_remote and dlm_move_lockres_to_recovery_list, which will cause a lock with OCFS2_LOCK_BUSY in grant list, thus system hangs. dlmconvert_remote { spin_lock(&res->spinlock); list_move_tail(&lock->list, &res->converting); lock->convert_pending = 1; spin_unlock(&res->spinlock); status = dlm_send_remote_convert_request(); >>>>>> race window, master has queued ast and return DLM_NORMAL, and then down before sending ast. this node detects master down and calls dlm_move_lockres_to_recovery_list, which will revert the lock to grant list. Then OCFS2_LOCK_BUSY won't be cleared as new master won't send ast any more because it thinks already be authorized. spin_lock(&res->spinlock); lock->convert_pending = 0; if (status != DLM_NORMAL) dlm_revert_pending_convert(res, lock); spin_unlock(&res->spinlock); } In this case, check if res->state has DLM_LOCK_RES_RECOVERING bit set (res is still in recovering) or res master changed (new master has finished recovery), reset the status to DLM_RECOVERING, then it will retry convert. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reported-by: Yiwen Jiang <jiangyiwen@huawei.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Tariq Saeed <tariq.x.saeed@oracle.com> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12writeback, cgroup: fix use of the wrong bdi_writeback which mismatches the inodeTejun Heo
commit aaf2559332ba272671bb870464a99b909b29a3a1 upstream. When cgroup writeback is in use, there can be multiple wb's (bdi_writeback's) per bdi and an inode may switch among them dynamically. In a couple places, the wrong wb was used leading to performing operations on the wrong list under the wrong lock corrupting the io lists. * writeback_single_inode() was taking @wb parameter and used it to remove the inode from io lists if it becomes clean after writeback. The callers of this function were always passing in the root wb regardless of the actual wb that the inode was associated with, which could also change while writeback is in progress. Fix it by dropping the @wb parameter and using inode_to_wb_and_lock_list() to determine and lock the associated wb. * After writeback_sb_inodes() writes out an inode, it re-locks @wb and inode to remove it from or move it to the right io list. It assumes that the inode is still associated with @wb; however, the inode may have switched to another wb while writeback was in progress. Fix it by using inode_to_wb_and_lock_list() to determine and lock the associated wb after writeback is complete. As the function requires the original @wb->list_lock locked for the next iteration, in the unlikely case where the inode has changed association, switch the locks. Kudos to Tahsin for pinpointing these subtle breakages. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: d10c80955265 ("writeback: implement foreign cgroup inode bdi_writeback switching") Link: http://lkml.kernel.org/g/CAAeU0aMYeM_39Y2+PaRvyB1nqAPYZSNngJ1eBRmrxn7gKAt2Mg@mail.gmail.com Reported-and-diagnosed-by: Tahsin Erdogan <tahsin@google.com> Tested-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12writeback, cgroup: fix premature wb_put() in locked_inode_to_wb_and_lock_list()Tejun Heo
commit 614a4e3773148a31f58dc174bbf578ceb63510c2 upstream. locked_inode_to_wb_and_lock_list() wb_get()'s the wb associated with the target inode, unlocks inode, locks the wb's list_lock and verifies that the inode is still associated with the wb. To prevent the wb going away between dropping inode lock and acquiring list_lock, the wb is pinned while inode lock is held. The wb reference is put right after acquiring list_lock citing that the wb won't be dereferenced anymore. This isn't true. If the inode is still associated with the wb, the inode has reference and it's safe to return the wb; however, if inode has been switched, the wb still needs to be unlocked which is a dereference and can lead to use-after-free if it it races with wb destruction. Fix it by putting the reference after releasing list_lock. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 87e1d789bf55 ("writeback: implement [locked_]inode_to_wb_and_lock_list()") Tested-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12nfsd: fix deadlock secinfo+readdir compoundJ. Bruce Fields
commit 2f6fc056e899bd0144a08da5cacaecbe8997cd74 upstream. nfsd_lookup_dentry exits with the parent filehandle locked. fh_put also unlocks if necessary (nfsd filehandle locking is probably too lenient), so it gets unlocked eventually, but if the following op in the compound needs to lock it again, we can deadlock. A fuzzer ran into this; normal clients don't send a secinfo followed by a readdir in the same compound. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>