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2017-09-13xfs: XFS_IS_REALTIME_INODE() should be false if no rt device presentRichard Wareing
commit b31ff3cdf540110da4572e3e29bd172087af65cc upstream. If using a kernel with CONFIG_XFS_RT=y and we set the RHINHERIT flag on a directory in a filesystem that does not have a realtime device and create a new file in that directory, it gets marked as a real time file. When data is written and a fsync is issued, the filesystem attempts to flush a non-existent rt device during the fsync process. This results in a crash dereferencing a null buftarg pointer in xfs_blkdev_issue_flush(): BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: xfs_blkdev_issue_flush+0xd/0x20 ..... Call Trace: xfs_file_fsync+0x188/0x1c0 vfs_fsync_range+0x3b/0xa0 do_fsync+0x3d/0x70 SyS_fsync+0x10/0x20 do_syscall_64+0x4d/0xb0 entry_SYSCALL64_slow_path+0x25/0x25 Setting RT inode flags does not require special privileges so any unprivileged user can cause this oops to occur. To reproduce, confirm kernel is compiled with CONFIG_XFS_RT=y and run: # mkfs.xfs -f /dev/pmem0 # mount /dev/pmem0 /mnt/test # mkdir /mnt/test/foo # xfs_io -c 'chattr +t' /mnt/test/foo # xfs_io -f -c 'pwrite 0 5m' -c fsync /mnt/test/foo/bar Or just run xfstests with MKFS_OPTIONS="-d rtinherit=1" and wait. Kernels built with CONFIG_XFS_RT=n are not exposed to this bug. Fixes: f538d4da8d52 ("[XFS] write barrier support") Signed-off-by: Richard Wareing <rwareing@fb.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-13NFS: Fix 2 use after free issues in the I/O codeTrond Myklebust
commit 196639ebbe63a037fe9a80669140bd292d8bcd80 upstream. The writeback code wants to send a commit after processing the pages, which is why we want to delay releasing the struct path until after that's done. Also, the layout code expects that we do not free the inode before we've put the layout segments in pnfs_writehdr_free() and pnfs_readhdr_free() Fixes: 919e3bd9a875 ("NFS: Ensure we commit after writeback is complete") Fixes: 4714fb51fd03 ("nfs: remove pgio_header refcount, related cleanup") Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-13btrfs: resume qgroup rescan on rw remountAleksa Sarai
commit 6c6b5a39c4bf3dbd8cf629c9f5450e983c19dbb9 upstream. Several distributions mount the "proper root" as ro during initrd and then remount it as rw before pivot_root(2). Thus, if a rescan had been aborted by a previous shutdown, the rescan would never be resumed. This issue would manifest itself as several btrfs ioctl(2)s causing the entire machine to hang when btrfs_qgroup_wait_for_completion was hit (due to the fs_info->qgroup_rescan_running flag being set but the rescan itself not being resumed). Notably, Docker's btrfs storage driver makes regular use of BTRFS_QUOTA_CTL_DISABLE and BTRFS_IOC_QUOTA_RESCAN_WAIT (causing this problem to be manifested on boot for some machines). Cc: Jeff Mahoney <jeffm@suse.com> Fixes: b382a324b60f ("Btrfs: fix qgroup rescan resume on mount") Signed-off-by: Aleksa Sarai <asarai@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-13dlm: avoid double-free on error path in dlm_device_{register,unregister}Edwin Török
commit 55acdd926f6b21a5cdba23da98a48aedf19ac9c3 upstream. Can be reproduced when running dlm_controld (tested on 4.4.x, 4.12.4): # seq 1 100 | xargs -P0 -n1 dlm_tool join # seq 1 100 | xargs -P0 -n1 dlm_tool leave misc_register fails due to duplicate sysfs entry, which causes dlm_device_register to free ls->ls_device.name. In dlm_device_deregister the name was freed again, causing memory corruption. According to the comment in dlm_device_deregister the name should've been set to NULL when registration fails, so this patch does that. sysfs: cannot create duplicate filename '/dev/char/10:1' ------------[ cut here ]------------ warning: cpu: 1 pid: 4450 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x56/0x70 modules linked in: msr rfcomm dlm ccm bnep dm_crypt uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core videodev btusb media btrtl btbcm btintel bluetooth ecdh_generic intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm snd_hda_codec_hdmi irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel thinkpad_acpi pcbc nvram snd_seq_midi snd_seq_midi_event aesni_intel snd_hda_codec_realtek snd_hda_codec_generic snd_rawmidi aes_x86_64 crypto_simd glue_helper snd_hda_intel snd_hda_codec cryptd intel_cstate arc4 snd_hda_core snd_seq snd_seq_device snd_hwdep iwldvm intel_rapl_perf mac80211 joydev input_leds iwlwifi serio_raw cfg80211 snd_pcm shpchp snd_timer snd mac_hid mei_me lpc_ich mei soundcore sunrpc parport_pc ppdev lp parport autofs4 i915 psmouse e1000e ahci libahci i2c_algo_bit sdhci_pci ptp drm_kms_helper sdhci pps_core syscopyarea sysfillrect sysimgblt fb_sys_fops drm wmi video cpu: 1 pid: 4450 comm: dlm_test.exe not tainted 4.12.4-041204-generic hardware name: lenovo 232425u/232425u, bios g2et82ww (2.02 ) 09/11/2012 task: ffff96b0cbabe140 task.stack: ffffb199027d0000 rip: 0010:sysfs_warn_dup+0x56/0x70 rsp: 0018:ffffb199027d3c58 eflags: 00010282 rax: 0000000000000038 rbx: ffff96b0e2c49158 rcx: 0000000000000006 rdx: 0000000000000000 rsi: 0000000000000086 rdi: ffff96b15e24dcc0 rbp: ffffb199027d3c70 r08: 0000000000000001 r09: 0000000000000721 r10: ffffb199027d3c00 r11: 0000000000000721 r12: ffffb199027d3cd1 r13: ffff96b1592088f0 r14: 0000000000000001 r15: ffffffffffffffef fs: 00007f78069c0700(0000) gs:ffff96b15e240000(0000) knlgs:0000000000000000 cs: 0010 ds: 0000 es: 0000 cr0: 0000000080050033 cr2: 000000178625ed28 cr3: 0000000091d3e000 cr4: 00000000001406e0 call trace: sysfs_do_create_link_sd.isra.2+0x9e/0xb0 sysfs_create_link+0x25/0x40 device_add+0x5a9/0x640 device_create_groups_vargs+0xe0/0xf0 device_create_with_groups+0x3f/0x60 ? snprintf+0x45/0x70 misc_register+0x140/0x180 device_write+0x6a8/0x790 [dlm] __vfs_write+0x37/0x160 ? apparmor_file_permission+0x1a/0x20 ? security_file_permission+0x3b/0xc0 vfs_write+0xb5/0x1a0 sys_write+0x55/0xc0 ? sys_fcntl+0x5d/0xb0 entry_syscall_64_fastpath+0x1e/0xa9 rip: 0033:0x7f78083454bd rsp: 002b:00007f78069bbd30 eflags: 00000293 orig_rax: 0000000000000001 rax: ffffffffffffffda rbx: 0000000000000006 rcx: 00007f78083454bd rdx: 000000000000009c rsi: 00007f78069bee00 rdi: 0000000000000005 rbp: 00007f77f8000a20 r08: 000000000000fcf0 r09: 0000000000000032 r10: 0000000000000024 r11: 0000000000000293 r12: 00007f78069bde00 r13: 00007f78069bee00 r14: 000000000000000a r15: 00007f78069bbd70 code: 85 c0 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef e8 2c c8 ff ff 4c 89 e2 48 89 de 48 c7 c7 b0 8e 0c a8 e8 41 e8 ed ff <0f> ff 48 89 df e8 00 d5 f4 ff 5b 41 5c 41 5d 5d c3 66 0f 1f 84 ---[ end trace 40412246357cc9e0 ]--- dlm: 59f24629-ae39-44e2-9030-397ebc2eda26: leaving the lockspace group... bug: unable to handle kernel null pointer dereference at 0000000000000001 ip: [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140 pgd 0 oops: 0000 [#1] smp modules linked in: dlm 8021q garp mrp stp llc openvswitch nf_defrag_ipv6 nf_conntrack libcrc32c iptable_filter dm_multipath crc32_pclmul dm_mod aesni_intel psmouse aes_x86_64 sg ablk_helper cryptd lrw gf128mul glue_helper i2c_piix4 nls_utf8 tpm_tis tpm isofs nfsd auth_rpcgss oid_registry nfs_acl lockd grace sunrpc xen_wdt ip_tables x_tables autofs4 hid_generic usbhid hid sr_mod cdrom sd_mod ata_generic pata_acpi 8139too serio_raw ata_piix 8139cp mii uhci_hcd ehci_pci ehci_hcd libata scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_mod ipv6 cpu: 0 pid: 394 comm: systemd-udevd tainted: g w 4.4.0+0 #1 hardware name: xen hvm domu, bios 4.7.2-2.2 05/11/2017 task: ffff880002410000 ti: ffff88000243c000 task.ti: ffff88000243c000 rip: e030:[<ffffffff811a3b4a>] [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140 rsp: e02b:ffff88000243fd90 eflags: 00010202 rax: 0000000000000000 rbx: ffff8800029864d0 rcx: 000000000007b36c rdx: 000000000007b36b rsi: 00000000024000c0 rdi: ffff880036801c00 rbp: ffff88000243fdc0 r08: 0000000000018880 r09: 0000000000000054 r10: 000000000000004a r11: ffff880034ace6c0 r12: 00000000024000c0 r13: ffff880036801c00 r14: 0000000000000001 r15: ffffffff8118dcc2 fs: 00007f0ab77548c0(0000) gs:ffff880036e00000(0000) knlgs:0000000000000000 cs: e033 ds: 0000 es: 0000 cr0: 0000000080050033 cr2: 0000000000000001 cr3: 000000000332d000 cr4: 0000000000040660 stack: ffffffff8118dc90 ffff8800029864d0 0000000000000000 ffff88003430b0b0 ffff880034b78320 ffff88003430b0b0 ffff88000243fdf8 ffffffff8118dcc2 ffff8800349c6700 ffff8800029864d0 000000000000000b 00007f0ab7754b90 call trace: [<ffffffff8118dc90>] ? anon_vma_fork+0x60/0x140 [<ffffffff8118dcc2>] anon_vma_fork+0x92/0x140 [<ffffffff8107033e>] copy_process+0xcae/0x1a80 [<ffffffff8107128b>] _do_fork+0x8b/0x2d0 [<ffffffff81071579>] sys_clone+0x19/0x20 [<ffffffff815a30ae>] entry_syscall_64_fastpath+0x12/0x71 ] code: f6 75 1c 4c 89 fa 44 89 e6 4c 89 ef e8 a7 e4 00 00 41 f7 c4 00 80 00 00 49 89 c6 74 47 eb 32 49 63 45 20 48 8d 4a 01 4d 8b 45 00 <49> 8b 1c 06 4c 89 f0 65 49 0f c7 08 0f 94 c0 84 c0 74 ac 49 63 rip [<ffffffff811a3b4a>] kmem_cache_alloc+0x7a/0x140 rsp <ffff88000243fd90> cr2: 0000000000000001 --[ end trace 70cb9fd1b164a0e8 ]-- Signed-off-by: Edwin Török <edvin.torok@citrix.com> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-07epoll: fix race between ep_poll_callback(POLLFREE) and ep_free()/ep_remove()Oleg Nesterov
commit 138e4ad67afd5c6c318b056b4d17c17f2c0ca5c0 upstream. The race was introduced by me in commit 971316f0503a ("epoll: ep_unregister_pollwait() can use the freed pwq->whead"). I did not realize that nothing can protect eventpoll after ep_poll_callback() sets ->whead = NULL, only whead->lock can save us from the race with ep_free() or ep_remove(). Move ->whead = NULL to the end of ep_poll_callback() and add the necessary barriers. TODO: cleanup the ewake/EPOLLEXCLUSIVE logic, it was confusing even before this patch. Hopefully this explains use-after-free reported by syzcaller: BUG: KASAN: use-after-free in debug_spin_lock_before ... _raw_spin_lock_irqsave+0x4a/0x60 kernel/locking/spinlock.c:159 ep_poll_callback+0x29f/0xff0 fs/eventpoll.c:1148 this is spin_lock(eventpoll->lock), ... Freed by task 17774: ... kfree+0xe8/0x2c0 mm/slub.c:3883 ep_free+0x22c/0x2a0 fs/eventpoll.c:865 Fixes: 971316f0503a ("epoll: ep_unregister_pollwait() can use the freed pwq->whead") Reported-by: 范龙飞 <long7573@126.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-07CIFS: remove endian related sparse warningSteve French
commit 6e3c1529c39e92ed64ca41d53abadabbaa1d5393 upstream. Recent patch had an endian warning ie cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup() Signed-off-by: Steve French <smfrench@gmail.com> CC: Ronnie Sahlberg <lsahlber@redhat.com> Acked-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-07CIFS: Fix maximum SMB2 header sizePavel Shilovsky
commit 9e37b1784f2be9397a903307574ee565bbadfd75 upstream. Currently the maximum size of SMB2/3 header is set incorrectly which leads to hanging of directory listing operations on encrypted SMB3 connections. Fix this by setting the maximum size to 170 bytes that is calculated as RFC1002 length field size (4) + transform header size (52) + SMB2 header size (64) + create response size (56). Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com> Acked-by: Sachin Prabhu <sprabhu@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-07ceph: fix readpage from fscacheYan, Zheng
commit dd2bc473482eedc60c29cf00ad12568ce40ce511 upstream. ceph_readpage() unlocks page prematurely prematurely in the case that page is reading from fscache. Caller of readpage expects that page is uptodate when it get unlocked. So page shoule get locked by completion callback of fscache_read_or_alloc_pages() Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-02btrfs: remove duplicate const specifierColin Ian King
commit fb75d857a31d600cc0c37b8c7d914014f7fa3f9a upstream. duplicate const is redundant so remove it Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30nfsd: Limit end of page list when decoding NFSv4 WRITEChuck Lever
commit fc788f64f1f3eb31e87d4f53bcf1ab76590d5838 upstream. When processing an NFSv4 WRITE operation, argp->end should never point past the end of the data in the final page of the page list. Otherwise, nfsd4_decode_compound can walk into uninitialized memory. More critical, nfsd4_decode_write is failing to increment argp->pagelen when it increments argp->pagelist. This can cause later xdr decoders to assume more data is available than really is, which can cause server crashes on malformed requests. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()Ronnie Sahlberg
commit d3edede29f74d335f81d95a4588f5f136a9f7dcf upstream. Add checking for the path component length and verify it is <= the maximum that the server advertizes via FileFsAttributeInformation. With this patch cifs.ko will now return ENAMETOOLONG instead of ENOENT when users to access an overlong path. To test this, try to cd into a (non-existing) directory on a CIFS share that has a too long name: cd /mnt/aaaaaaaaaaaaaaa... and it now should show a good error message from the shell: bash: cd: /mnt/aaaaaaaaaaaaaaaa...aaaaaa: File name too long rh bz 1153996 Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30cifs: Fix df output for users with quota limitsSachin Prabhu
commit 42bec214d8bd432be6d32a1acb0a9079ecd4d142 upstream. The df for a SMB2 share triggers a GetInfo call for FS_FULL_SIZE_INFORMATION. The values returned are used to populate struct statfs. The problem is that none of the information returned by the call contains the total blocks available on the filesystem. Instead we use the blocks available to the user ie. quota limitation when filling out statfs.f_blocks. The information returned does contain Actual free units on the filesystem and is used to populate statfs.f_bfree. For users with quota enabled, it can lead to situations where the total free space reported is more than the total blocks on the system ending up with df reports like the following # df -h /mnt/a Filesystem Size Used Avail Use% Mounted on //192.168.22.10/a 2.5G -2.3G 2.5G - /mnt/a To fix this problem, we instead populate both statfs.f_bfree with the same value as statfs.f_bavail ie. CallerAvailableAllocationUnits. This is similar to what is done already in the code for cifs and df now reports the quota information for the user used to mount the share. # df --si /mnt/a Filesystem Size Used Avail Use% Mounted on //192.168.22.10/a 2.7G 101M 2.6G 4% /mnt/a Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Signed-off-by: Pierguido Lambri <plambri@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16pnfs/blocklayout: require 64-bit sector_tChristoph Hellwig
commit 8a9d6e964d318533ba3d2901ce153ba317c99a89 upstream. The blocklayout code does not compile cleanly for a 32-bit sector_t, and also has no reliable checks for devices sizes, which makes it unsafe to use with a kernel that doesn't support large block devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Arnd Bergmann <arnd@arndb.de> Fixes: 5c83746a0cf2 ("pnfs/blocklayout: in-kernel GETDEVICEINFO XDR parsing") Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16nfs/flexfiles: fix leak of nfs4_ff_ds_version arraysWeston Andros Adamson
commit 1feb26162bee7b2f110facfec71b5c7bdbc7d14d upstream. The client was freeing the nfs4_ff_layout_ds, but not the contained nfs4_ff_ds_version array. Signed-off-by: Weston Andros Adamson <dros@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-16fuse: initialize the flock flag in fuse_file on allocationMateusz Jurczyk
commit 68227c03cba84a24faf8a7277d2b1a03c8959c2c upstream. Before the patch, the flock flag could remain uninitialized for the lifespan of the fuse_file allocation. Unless set to true in fuse_file_flock(), it would remain in an indeterminate state until read in an if statement in fuse_release_common(). This could consequently lead to taking an unexpected branch in the code. The bug was discovered by a runtime instrumentation designed to detect use of uninitialized memory in the kernel. Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com> Fixes: 37fb3a30b462 ("fuse: fix flock") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11f2fs: sanity check checkpoint segno and blkoffJin Qian
commit 15d3042a937c13f5d9244241c7a9c8416ff6e82a upstream. Make sure segno and blkoff read from raw image are valid. Cc: stable@vger.kernel.org Signed-off-by: Jin Qian <jinqian@google.com> [Jaegeuk Kim: adjust minor coding style] Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> [AmitP: Found in Android Security bulletin for Aug'17, fixes CVE-2017-10663] Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11ext4: fix overflow caused by missing cast in ext4_resize_fs()Jerry Lee
commit aec51758ce10a9c847a62a48a168f8c804c6e053 upstream. On a 32-bit platform, the value of n_blcoks_count may be wrong during the file system is resized to size larger than 2^32 blocks. This may caused the superblock being corrupted with zero blocks count. Fixes: 1c6bd7173d66 Signed-off-by: Jerry Lee <jerrylee@qnap.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11ext4: fix SEEK_HOLE/SEEK_DATA for blocksize < pagesizeJan Kara
commit fcf5ea10992fbac3c7473a1db33d56a139333cd1 upstream. ext4_find_unwritten_pgoff() does not properly handle a situation when starting index is in the middle of a page and blocksize < pagesize. The following command shows the bug on filesystem with 1k blocksize: xfs_io -f -c "falloc 0 4k" \ -c "pwrite 1k 1k" \ -c "pwrite 3k 1k" \ -c "seek -a -r 0" foo In this example, neither lseek(fd, 1024, SEEK_HOLE) nor lseek(fd, 2048, SEEK_DATA) will return the correct result. Fix the problem by neglecting buffers in a page before starting offset. Reported-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06Btrfs: adjust outstanding_extents counter properly when dio write is splitLiu Bo
[ Upstream commit c2931667c83ded6504b3857e99cc45b21fa496fb ] Currently how btrfs dio deals with split dio write is not good enough if dio write is split into several segments due to the lack of contiguous space, a large dio write like 'dd bs=1G count=1' can end up with incorrect outstanding_extents counter and endio would complain loudly with an assertion. This fixes the problem by compensating the outstanding_extents counter in inode if a large dio write gets split. Reported-by: Anand Jain <anand.jain@oracle.com> Tested-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06pstore: Use dynamic spinlock initializerKees Cook
commit e9a330c4289f2ba1ca4bf98c2b430ab165a8931b upstream. The per-prz spinlock should be using the dynamic initializer so that lockdep can correctly track it. Without this, under lockdep, we get a warning at boot that the lock is in non-static memory. Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Fixes: 76d5692a5803 ("pstore: Correctly initialize spinlock and flags") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06pstore: Correctly initialize spinlock and flagsKees Cook
commit 76d5692a58031696e282384cbd893832bc92bd76 upstream. The ram backend wasn't always initializing its spinlock correctly. Since it was coming from kzalloc memory, though, it was harmless on architectures that initialize unlocked spinlocks to 0 (at least x86 and ARM). This also fixes a possibly ignored flag setting too. When running under CONFIG_DEBUG_SPINLOCK, the following Oops was visible: [ 0.760836] persistent_ram: found existing buffer, size 29988, start 29988 [ 0.765112] persistent_ram: found existing buffer, size 30105, start 30105 [ 0.769435] persistent_ram: found existing buffer, size 118542, start 118542 [ 0.785960] persistent_ram: found existing buffer, size 0, start 0 [ 0.786098] persistent_ram: found existing buffer, size 0, start 0 [ 0.786131] pstore: using zlib compression [ 0.790716] BUG: spinlock bad magic on CPU#0, swapper/0/1 [ 0.790729] lock: 0xffffffc0d1ca9bb0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 0.790742] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-rc2+ #913 [ 0.790747] Hardware name: Google Kevin (DT) [ 0.790750] Call trace: [ 0.790768] [<ffffff900808ae88>] dump_backtrace+0x0/0x2bc [ 0.790780] [<ffffff900808b164>] show_stack+0x20/0x28 [ 0.790794] [<ffffff9008460ee0>] dump_stack+0xa4/0xcc [ 0.790809] [<ffffff9008113cfc>] spin_dump+0xe0/0xf0 [ 0.790821] [<ffffff9008113d3c>] spin_bug+0x30/0x3c [ 0.790834] [<ffffff9008113e28>] do_raw_spin_lock+0x50/0x1b8 [ 0.790846] [<ffffff9008a2d2ec>] _raw_spin_lock_irqsave+0x54/0x6c [ 0.790862] [<ffffff90083ac3b4>] buffer_size_add+0x48/0xcc [ 0.790875] [<ffffff90083acb34>] persistent_ram_write+0x60/0x11c [ 0.790888] [<ffffff90083aab1c>] ramoops_pstore_write_buf+0xd4/0x2a4 [ 0.790900] [<ffffff90083a9d3c>] pstore_console_write+0xf0/0x134 [ 0.790912] [<ffffff900811c304>] console_unlock+0x48c/0x5e8 [ 0.790923] [<ffffff900811da18>] register_console+0x3b0/0x4d4 [ 0.790935] [<ffffff90083aa7d0>] pstore_register+0x1a8/0x234 [ 0.790947] [<ffffff90083ac250>] ramoops_probe+0x6b8/0x7d4 [ 0.790961] [<ffffff90085ca548>] platform_drv_probe+0x7c/0xd0 [ 0.790972] [<ffffff90085c76ac>] driver_probe_device+0x1b4/0x3bc [ 0.790982] [<ffffff90085c7ac8>] __device_attach_driver+0xc8/0xf4 [ 0.790996] [<ffffff90085c4bfc>] bus_for_each_drv+0xb4/0xe4 [ 0.791006] [<ffffff90085c7414>] __device_attach+0xd0/0x158 [ 0.791016] [<ffffff90085c7b18>] device_initial_probe+0x24/0x30 [ 0.791026] [<ffffff90085c648c>] bus_probe_device+0x50/0xe4 [ 0.791038] [<ffffff90085c35b8>] device_add+0x3a4/0x76c [ 0.791051] [<ffffff90087d0e84>] of_device_add+0x74/0x84 [ 0.791062] [<ffffff90087d19b8>] of_platform_device_create_pdata+0xc0/0x100 [ 0.791073] [<ffffff90087d1a2c>] of_platform_device_create+0x34/0x40 [ 0.791086] [<ffffff900903c910>] of_platform_default_populate_init+0x58/0x78 [ 0.791097] [<ffffff90080831fc>] do_one_initcall+0x88/0x160 [ 0.791109] [<ffffff90090010ac>] kernel_init_freeable+0x264/0x31c [ 0.791123] [<ffffff9008a25bd0>] kernel_init+0x18/0x11c [ 0.791133] [<ffffff9008082ec0>] ret_from_fork+0x10/0x50 [ 0.793717] console [pstore-1] enabled [ 0.797845] pstore: Registered ramoops as persistent store backend [ 0.804647] ramoops: attached 0x100000@0xf7edc000, ecc: 0/0 Fixes: 663deb47880f ("pstore: Allow prz to control need for locking") Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Reported-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06pstore: Allow prz to control need for lockingJoel Fernandes
commit 663deb47880f2283809669563c5a52ac7c6aef1a upstream. In preparation of not locking at all for certain buffers depending on if there's contention, make locking optional depending on the initialization of the prz. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: moved locking flag into prz instead of via caller arguments] Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06Make file credentials available to the seqfile interfacesLinus Torvalds
commit 34dbbcdbf63360661ff7bda6c5f52f99ac515f92 upstream. A lot of seqfile users seem to be using things like %pK that uses the credentials of the current process, but that is actually completely wrong for filesystem interfaces. The unix semantics for permission checking files is to check permissions at _open_ time, not at read or write time, and that is not just a small detail: passing off stdin/stdout/stderr to a suid application and making the actual IO happen in privileged context is a classic exploit technique. So if we want to be able to look at permissions at read time, we need to use the file open credentials, not the current ones. Normal file accesses can just use "f_cred" (or any of the helper functions that do that, like file_ns_capable()), but the seqfile interfaces do not have any such options. It turns out that seq_file _does_ save away the user_ns information of the file, though. Since user_ns is just part of the full credential information, replace that special case with saving off the cred pointer instead, and suddenly seq_file has all the permission information it needs. [sumits: this is used in Ubuntu as a fix for CVE-2015-8944] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06dentry name snapshotsAl Viro
commit 49d31c2f389acfe83417083e1208422b4091cd9e upstream. take_dentry_name_snapshot() takes a safe snapshot of dentry name; if the name is a short one, it gets copied into caller-supplied structure, otherwise an extra reference to external name is grabbed (those are never modified). In either case the pointer to stable string is stored into the same structure. dentry must be held by the caller of take_dentry_name_snapshot(), but may be freely dropped afterwards - the snapshot will stay until destroyed by release_dentry_name_snapshot(). Intended use: struct name_snapshot s; take_dentry_name_snapshot(&s, dentry); ... access s.name ... release_dentry_name_snapshot(&s); Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name to pass down with event. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06xfs: don't BUG() on mixed direct and mapped I/OBrian Foster
commit 04197b341f23b908193308b8d63d17ff23232598 upstream. We've had reports of generic/095 causing XFS to BUG() in __xfs_get_blocks() due to the existence of delalloc blocks on a direct I/O read. generic/095 issues a mix of various types of I/O, including direct and memory mapped I/O to a single file. This is clearly not supported behavior and is known to lead to such problems. E.g., the lack of exclusion between the direct I/O and write fault paths means that a write fault can allocate delalloc blocks in a region of a file that was previously a hole after the direct read has attempted to flush/inval the file range, but before it actually reads the block mapping. In turn, the direct read discovers a delalloc extent and cannot proceed. While the appropriate solution here is to not mix direct and memory mapped I/O to the same regions of the same file, the current BUG_ON() behavior is probably overkill as it can crash the entire system. Instead, localize the failure to the I/O in question by returning an error for a direct I/O that cannot be handled safely due to delalloc blocks. Be careful to allow the case of a direct write to post-eof delalloc blocks. This can occur due to speculative preallocation and is safe as post-eof blocks are not accompanied by dirty pages in pagecache (conversely, preallocation within eof must have been zeroed, and thus dirtied, before the inode size could have been increased beyond said blocks). Finally, provide an additional warning if a direct I/O write occurs while the file is memory mapped. This may not catch all problematic scenarios, but provides a hint that some known-to-be-problematic I/O methods are in use. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Acked-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-06pstore: Make spinlock per zone instead of globalJoel Fernandes
commit 109704492ef637956265ec2eb72ae7b3b39eb6f4 upstream. Currently pstore has a global spinlock for all zones. Since the zones are independent and modify different areas of memory, there's no need to have a global lock, so we should use a per-zone lock as introduced here. Also, when ramoops's ftrace use-case has a FTRACE_PER_CPU flag introduced later, which splits the ftrace memory area into a single zone per CPU, it will eliminate the need for locking. In preparation for this, make the locking optional. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: updated commit message] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Leo Yan <leo.yan@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27ceph: fix race in concurrent readdirYan, Zheng
commit 84583cfb973c4313955c6231cc9cb3772d280b15 upstream. For a large directory, program needs to issue multiple readdir syscalls to get all dentries. When there are multiple programs read the directory concurrently. Following sequence of events can happen. - program calls readdir with pos = 2. ceph sends readdir request to mds. The reply contains N1 entries. ceph adds these N1 entries to readdir cache. - program calls readdir with pos = N1+2. The readdir is satisfied by the readdir cache, N2 entries are returned. (Other program calls readdir in the middle, which fills the cache) - program calls readdir with pos = N1+N2+2. ceph sends readdir request to mds. The reply contains N3 entries and it reaches directory end. ceph adds these N3 entries to the readdir cache and marks directory complete. The second readdir call does not update fi->readdir_cache_idx. ceph add the last N3 entries to wrong places. Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27udf: Fix deadlock between writeback and udf_setsize()Jan Kara
commit f2e95355891153f66d4156bf3a142c6489cd78c6 upstream. udf_setsize() called truncate_setsize() with i_data_sem held. Thus truncate_pagecache() called from truncate_setsize() could lock a page under i_data_sem which can deadlock as page lock ranks below i_data_sem - e. g. writeback can hold page lock and try to acquire i_data_sem to map a block. Fix the problem by moving truncate_setsize() calls from under i_data_sem. It is safe for us to change i_size without holding i_data_sem as all the places that depend on i_size being stable already hold inode_lock. Fixes: 7e49b6f2480cb9a9e7322a91592e56a5c85361f5 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27NFS: only invalidate dentrys that are clearly invalid.NeilBrown
commit cc89684c9a265828ce061037f1f79f4a68ccd3f7 upstream. Since commit bafc9b754f75 ("vfs: More precise tests in d_invalidate") in v3.18, a return of '0' from ->d_revalidate() will cause the dentry to be invalidated even if it has filesystems mounted on or it or on a descendant. The mounted filesystem is unmounted. This means we need to be careful not to return 0 unless the directory referred to truly is invalid. So -ESTALE or -ENOENT should invalidate the directory. Other errors such a -EPERM or -ERESTARTSYS should be returned from ->d_revalidate() so they are propagated to the caller. A particular problem can be demonstrated by: 1/ mount an NFS filesystem using NFSv3 on /mnt 2/ mount any other filesystem on /mnt/foo 3/ ls /mnt/foo 4/ turn off network, or otherwise make the server unable to respond 5/ ls /mnt/foo & 6/ cat /proc/$!/stack # note that nfs_lookup_revalidate is in the call stack 7/ kill -9 $! # this results in -ERESTARTSYS being returned 8/ observe that /mnt/foo has been unmounted. This patch changes nfs_lookup_revalidate() to only treat -ESTALE from nfs_lookup_verify_inode() and -ESTALE or -ENOENT from ->lookup() as indicating an invalid inode. Other errors are returned. Also nfs_check_inode_attributes() is changed to return -ESTALE rather than -EIO. This is consistent with the error returned in similar circumstances from nfs_update_inode(). As this bug allows any user to unmount a filesystem mounted on an NFS filesystem, this fix is suitable for stable kernels. Fixes: bafc9b754f75 ("vfs: More precise tests in d_invalidate") Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27f2fs: Don't clear SGID when inheriting ACLsJaegeuk Kim
commit c925dc162f770578ff4a65ec9b08270382dba9e6 upstream. This patch copies commit b7f8a09f80: "btrfs: Don't clear SGID when inheriting ACLs" written by Jan. Fixes: 073931017b49d9458aa351605b43a7e34598caef Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Chao Yu <yuchao0@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21mnt: Make propagate_umount less slow for overlapping mount propagation treesEric W. Biederman
commit 296990deb389c7da21c78030376ba244dc1badf5 upstream. Andrei Vagin pointed out that time to executue propagate_umount can go non-linear (and take a ludicrious amount of time) when the mount propogation trees of the mounts to be unmunted by a lazy unmount overlap. Make the walk of the mount propagation trees nearly linear by remembering which mounts have already been visited, allowing subsequent walks to detect when walking a mount propgation tree or a subtree of a mount propgation tree would be duplicate work and to skip them entirely. Walk the list of mounts whose propgatation trees need to be traversed from the mount highest in the mount tree to mounts lower in the mount tree so that odds are higher that the code will walk the largest trees first, allowing later tree walks to be skipped entirely. Add cleanup_umount_visitation to remover the code's memory of which mounts have been visited. Add the functions last_slave and skip_propagation_subtree to allow skipping appropriate parts of the mount propagation tree without needing to change the logic of the rest of the code. A script to generate overlapping mount propagation trees: $ cat runs.h set -e mount -t tmpfs zdtm /mnt mkdir -p /mnt/1 /mnt/2 mount -t tmpfs zdtm /mnt/1 mount --make-shared /mnt/1 mkdir /mnt/1/1 iteration=10 if [ -n "$1" ] ; then iteration=$1 fi for i in $(seq $iteration); do mount --bind /mnt/1/1 /mnt/1/1 done mount --rbind /mnt/1 /mnt/2 TIMEFORMAT='%Rs' nr=$(( ( 2 ** ( $iteration + 1 ) ) + 1 )) echo -n "umount -l /mnt/1 -> $nr " time umount -l /mnt/1 nr=$(cat /proc/self/mountinfo | grep zdtm | wc -l ) time umount -l /mnt/2 $ for i in $(seq 9 19); do echo $i; unshare -Urm bash ./run.sh $i; done Here are the performance numbers with and without the patch: mhash | 8192 | 8192 | 1048576 | 1048576 mounts | before | after | before | after ------------------------------------------------ 1025 | 0.040s | 0.016s | 0.038s | 0.019s 2049 | 0.094s | 0.017s | 0.080s | 0.018s 4097 | 0.243s | 0.019s | 0.206s | 0.023s 8193 | 1.202s | 0.028s | 1.562s | 0.032s 16385 | 9.635s | 0.036s | 9.952s | 0.041s 32769 | 60.928s | 0.063s | 44.321s | 0.064s 65537 | | 0.097s | | 0.097s 131073 | | 0.233s | | 0.176s 262145 | | 0.653s | | 0.344s 524289 | | 2.305s | | 0.735s 1048577 | | 7.107s | | 2.603s Andrei Vagin reports fixing the performance problem is part of the work to fix CVE-2016-6213. Fixes: a05964f3917c ("[PATCH] shared mounts handling: umount") Reported-by: Andrei Vagin <avagin@openvz.org> Reviewed-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21mnt: In propgate_umount handle visiting mounts in any orderEric W. Biederman
commit 99b19d16471e9c3faa85cad38abc9cbbe04c6d55 upstream. While investigating some poor umount performance I realized that in the case of overlapping mount trees where some of the mounts are locked the code has been failing to unmount all of the mounts it should have been unmounting. This failure to unmount all of the necessary mounts can be reproduced with: $ cat locked_mounts_test.sh mount -t tmpfs test-base /mnt mount --make-shared /mnt mkdir -p /mnt/b mount -t tmpfs test1 /mnt/b mount --make-shared /mnt/b mkdir -p /mnt/b/10 mount -t tmpfs test2 /mnt/b/10 mount --make-shared /mnt/b/10 mkdir -p /mnt/b/10/20 mount --rbind /mnt/b /mnt/b/10/20 unshare -Urm --propagation unchaged /bin/sh -c 'sleep 5; if [ $(grep test /proc/self/mountinfo | wc -l) -eq 1 ] ; then echo SUCCESS ; else echo FAILURE ; fi' sleep 1 umount -l /mnt/b wait %% $ unshare -Urm ./locked_mounts_test.sh This failure is corrected by removing the prepass that marks mounts that may be umounted. A first pass is added that umounts mounts if possible and if not sets mount mark if they could be unmounted if they weren't locked and adds them to a list to umount possibilities. This first pass reconsiders the mounts parent if it is on the list of umount possibilities, ensuring that information of umoutability will pass from child to mount parent. A second pass then walks through all mounts that are umounted and processes their children unmounting them or marking them for reparenting. A last pass cleans up the state on the mounts that could not be umounted and if applicable reparents them to their first parent that remained mounted. While a bit longer than the old code this code is much more robust as it allows information to flow up from the leaves and down from the trunk making the order in which mounts are encountered in the umount propgation tree irrelevant. Fixes: 0c56fe31420c ("mnt: Don't propagate unmounts to locked mounts") Reviewed-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21mnt: In umount propagation reparent in a separate passEric W. Biederman
commit 570487d3faf2a1d8a220e6ee10f472163123d7da upstream. It was observed that in some pathlogical cases that the current code does not unmount everything it should. After investigation it was determined that the issue is that mnt_change_mntpoint can can change which mounts are available to be unmounted during mount propagation which is wrong. The trivial reproducer is: $ cat ./pathological.sh mount -t tmpfs test-base /mnt cd /mnt mkdir 1 2 1/1 mount --bind 1 1 mount --make-shared 1 mount --bind 1 2 mount --bind 1/1 1/1 mount --bind 1/1 1/1 echo grep test-base /proc/self/mountinfo umount 1/1 echo grep test-base /proc/self/mountinfo $ unshare -Urm ./pathological.sh The expected output looks like: 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 49 54 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 50 53 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 51 49 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 54 47 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 53 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 52 50 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 The output without the fix looks like: 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 49 54 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 50 53 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 51 49 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 54 47 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 53 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 52 50 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 52 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 That last mount in the output was in the propgation tree to be unmounted but was missed because the mnt_change_mountpoint changed it's parent before the walk through the mount propagation tree observed it. Fixes: 1064f874abc0 ("mnt: Tuck mounts under others instead of creating shadow/side mounts.") Acked-by: Andrei Vagin <avagin@virtuozzo.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21exec: Limit arg stack to at most 75% of _STK_LIMKees Cook
commit da029c11e6b12f321f36dac8771e833b65cec962 upstream. To avoid pathological stack usage or the need to special-case setuid execs, just limit all arg stack usage to at most 75% of _STK_LIM (6MB). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21binfmt_elf: use ELF_ET_DYN_BASE only for PIEKees Cook
commit eab09532d40090698b05a07c1c87f39fdbc5fab5 upstream. The ELF_ET_DYN_BASE position was originally intended to keep loaders away from ET_EXEC binaries. (For example, running "/lib/ld-linux.so.2 /bin/cat" might cause the subsequent load of /bin/cat into where the loader had been loaded.) With the advent of PIE (ET_DYN binaries with an INTERP Program Header), ELF_ET_DYN_BASE continued to be used since the kernel was only looking at ET_DYN. However, since ELF_ET_DYN_BASE is traditionally set at the top 1/3rd of the TASK_SIZE, a substantial portion of the address space is unused. For 32-bit tasks when RLIMIT_STACK is set to RLIM_INFINITY, programs are loaded above the mmap region. This means they can be made to collide (CVE-2017-1000370) or nearly collide (CVE-2017-1000371) with pathological stack regions. Lowering ELF_ET_DYN_BASE solves both by moving programs below the mmap region in all cases, and will now additionally avoid programs falling back to the mmap region by enforcing MAP_FIXED for program loads (i.e. if it would have collided with the stack, now it will fail to load instead of falling back to the mmap region). To allow for a lower ELF_ET_DYN_BASE, loaders (ET_DYN without INTERP) are loaded into the mmap region, leaving space available for either an ET_EXEC binary with a fixed location or PIE being loaded into mmap by the loader. Only PIE programs are loaded offset from ELF_ET_DYN_BASE, which means architectures can now safely lower their values without risk of loaders colliding with their subsequently loaded programs. For 64-bit, ELF_ET_DYN_BASE is best set to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. Thanks to PaX Team, Daniel Micay, and Rik van Riel for inspiration and suggestions on how to implement this solution. Fixes: d1fd836dcf00 ("mm: split ET_DYN ASLR from mmap ASLR") Link: http://lkml.kernel.org/r/20170621173201.GA114489@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Daniel Micay <danielmicay@gmail.com> Cc: Qualys Security Advisory <qsa@qualys.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Pratyush Anand <panand@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.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>
2017-07-21fs/dcache.c: fix spin lockup issue on nlru->lockSahitya Tummala
commit b17c070fb624cf10162cf92ea5e1ec25cd8ac176 upstream. __list_lru_walk_one() acquires nlru spin lock (nlru->lock) for longer duration if there are more number of items in the lru list. As per the current code, it can hold the spin lock for upto maximum UINT_MAX entries at a time. So if there are more number of items in the lru list, then "BUG: spinlock lockup suspected" is observed in the below path: spin_bug+0x90 do_raw_spin_lock+0xfc _raw_spin_lock+0x28 list_lru_add+0x28 dput+0x1c8 path_put+0x20 terminate_walk+0x3c path_lookupat+0x100 filename_lookup+0x6c user_path_at_empty+0x54 SyS_faccessat+0xd0 el0_svc_naked+0x24 This nlru->lock is acquired by another CPU in this path - d_lru_shrink_move+0x34 dentry_lru_isolate_shrink+0x48 __list_lru_walk_one.isra.10+0x94 list_lru_walk_node+0x40 shrink_dcache_sb+0x60 do_remount_sb+0xbc do_emergency_remount+0xb0 process_one_work+0x228 worker_thread+0x2e0 kthread+0xf4 ret_from_fork+0x10 Fix this lockup by reducing the number of entries to be shrinked from the lru list to 1024 at once. Also, add cond_resched() before processing the lru list again. Link: http://marc.info/?t=149722864900001&r=1&w=2 Link: http://lkml.kernel.org/r/1498707575-2472-1-git-send-email-stummala@codeaurora.org Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> Suggested-by: Jan Kara <jack@suse.cz> Suggested-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Alexander Polakov <apolyakov@beget.ru> Cc: Al Viro <viro@zeniv.linux.org.uk> 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>
2017-07-15ext4: check return value of kstrtoull correctly in reserved_clusters_storeChao Yu
commit 1ea1516fbbab2b30bf98c534ecaacba579a35208 upstream. kstrtoull returns 0 on success, however, in reserved_clusters_store we will return -EINVAL if kstrtoull returns 0, it makes us fail to update reserved_clusters value through sysfs. Fixes: 76d33bca5581b1dd5c3157fa168db849a784ada4 Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Miao Xie <miaoxie@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-15gfs2: Fix glock rhashtable rcu bugAndreas Gruenbacher
commit 961ae1d83d055a4b9ebbfb4cc8ca62ec1a7a3b74 upstream. Before commit 88ffbf3e03 "GFS2: Use resizable hash table for glocks", glocks were freed via call_rcu to allow reading the glock hashtable locklessly using rcu. This was then changed to free glocks immediately, which made reading the glock hashtable unsafe. Bring back the original code for freeing glocks via call_rcu. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-15fs: completely ignore unknown open flagsChristoph Hellwig
commit 629e014bb8349fcf7c1e4df19a842652ece1c945 upstream. Currently we just stash anything we got into file->f_flags, and the report it in fcntl(F_GETFD). This patch just clears out all unknown flags so that we don't pass them to the fs or report them. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-15fs: add a VALID_OPEN_FLAGSChristoph Hellwig
commit 80f18379a7c350c011d30332658aa15fe49a8fa5 upstream. Add a central define for all valid open flags, and use it in the uniqueness check. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05ocfs2: o2hb: revert hb threshold to keep compatibleJunxiao Bi
commit 33496c3c3d7b88dcbe5e55aa01288b05646c6aca upstream. Configfs is the interface for ocfs2-tools to set configure to kernel and $configfs_dir/cluster/$clustername/heartbeat/dead_threshold is the one used to configure heartbeat dead threshold. Kernel has a default value of it but user can set O2CB_HEARTBEAT_THRESHOLD in /etc/sysconfig/o2cb to override it. Commit 45b997737a80 ("ocfs2/cluster: use per-attribute show and store methods") changed heartbeat dead threshold name while ocfs2-tools did not, so ocfs2-tools won't set this configurable and the default value is always used. So revert it. Fixes: 45b997737a80 ("ocfs2/cluster: use per-attribute show and store methods") Link: http://lkml.kernel.org/r/1490665245-15374-1-git-send-email-junxiao.bi@oracle.com Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Acked-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> 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>
2017-07-05coredump: Ensure proper size of sparse core filesDave Kleikamp
[ Upstream commit 4d22c75d4c7b5c5f4bd31054f09103ee490878fd ] If the last section of a core file ends with an unmapped or zero page, the size of the file does not correspond with the last dump_skip() call. gdb complains that the file is truncated and can be confusing to users. After all of the vma sections are written, make sure that the file size is no smaller than the current file position. This problem can be demonstrated with gdb's bigcore testcase on the sparc architecture. Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05Btrfs: fix truncate down when no_holes feature is enabledLiu Bo
[ Upstream commit 91298eec05cd8d4e828cf7ee5d4a6334f70cf69a ] For such a file mapping, [0-4k][hole][8k-12k] In NO_HOLES mode, we don't have the [hole] extent any more. Commit c1aa45759e90 ("Btrfs: fix shrinking truncate when the no_holes feature is enabled") fixed disk isize not being updated in NO_HOLES mode when data is not flushed. However, even if data has been flushed, we can still have trouble in updating disk isize since we updated disk isize to 'start' of the last evicted extent. Reviewed-by: Chris Mason <clm@fb.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05NFSv4: fix a reference leak caused WARNING messagesKinglong Mee
commit 366a1569bff3fe14abfdf9285e31e05e091745f5 upstream. Because nfs4_opendata_access() has close the state when access is denied, so the state isn't leak. Rather than revert the commit a974deee47, I'd like clean the strange state close. [ 1615.094218] ------------[ cut here ]------------ [ 1615.094607] WARNING: CPU: 0 PID: 23702 at lib/list_debug.c:31 __list_add_valid+0x8e/0xa0 [ 1615.094913] list_add double add: new=ffff9d7901d9f608, prev=ffff9d7901d9f608, next=ffff9d7901ee8dd0. [ 1615.095458] Modules linked in: nfsv4(E) nfs(E) nfsd(E) tun bridge stp llc fuse ip_set nfnetlink vmw_vsock_vmci_transport vsock f2fs snd_seq_midi snd_seq_midi_event fscrypto coretemp ppdev crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_rapl_perf vmw_balloon snd_ens1371 joydev gameport snd_ac97_codec ac97_bus snd_seq snd_pcm snd_rawmidi snd_timer snd_seq_device snd soundcore nfit parport_pc parport acpi_cpufreq tpm_tis tpm_tis_core tpm i2c_piix4 vmw_vmci shpchp auth_rpcgss nfs_acl lockd(E) grace sunrpc(E) xfs libcrc32c vmwgfx drm_kms_helper ttm drm crc32c_intel mptspi e1000 serio_raw scsi_transport_spi mptscsih mptbase ata_generic pata_acpi fjes [last unloaded: nfs] [ 1615.097663] CPU: 0 PID: 23702 Comm: fstest Tainted: G W E 4.11.0-rc1+ #517 [ 1615.098015] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 [ 1615.098807] Call Trace: [ 1615.099183] dump_stack+0x63/0x86 [ 1615.099578] __warn+0xcb/0xf0 [ 1615.099967] warn_slowpath_fmt+0x5f/0x80 [ 1615.100370] __list_add_valid+0x8e/0xa0 [ 1615.100760] nfs4_put_state_owner+0x75/0xc0 [nfsv4] [ 1615.101136] __nfs4_close+0x109/0x140 [nfsv4] [ 1615.101524] nfs4_close_state+0x15/0x20 [nfsv4] [ 1615.101949] nfs4_close_context+0x21/0x30 [nfsv4] [ 1615.102691] __put_nfs_open_context+0xb8/0x110 [nfs] [ 1615.103155] put_nfs_open_context+0x10/0x20 [nfs] [ 1615.103586] nfs4_file_open+0x13b/0x260 [nfsv4] [ 1615.103978] do_dentry_open+0x20a/0x2f0 [ 1615.104369] ? nfs4_copy_file_range+0x30/0x30 [nfsv4] [ 1615.104739] vfs_open+0x4c/0x70 [ 1615.105106] ? may_open+0x5a/0x100 [ 1615.105469] path_openat+0x623/0x1420 [ 1615.105823] do_filp_open+0x91/0x100 [ 1615.106174] ? __alloc_fd+0x3f/0x170 [ 1615.106568] do_sys_open+0x130/0x220 [ 1615.106920] ? __put_cred+0x3d/0x50 [ 1615.107256] SyS_open+0x1e/0x20 [ 1615.107588] entry_SYSCALL_64_fastpath+0x1a/0xa9 [ 1615.107922] RIP: 0033:0x7fab599069b0 [ 1615.108247] RSP: 002b:00007ffcf0600d78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 1615.108575] RAX: ffffffffffffffda RBX: 00007fab59bcfae0 RCX: 00007fab599069b0 [ 1615.108896] RDX: 0000000000000200 RSI: 0000000000000200 RDI: 00007ffcf060255e [ 1615.109211] RBP: 0000000000040010 R08: 0000000000000000 R09: 0000000000000016 [ 1615.109515] R10: 00000000000006a1 R11: 0000000000000246 R12: 0000000000041000 [ 1615.109806] R13: 0000000000040010 R14: 0000000000001000 R15: 0000000000002710 [ 1615.110152] ---[ end trace 96ed63b1306bf2f3 ]--- Fixes: a974deee47 ("NFSv4: Fix memory and state leak in...") Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29CIFS: Improve readdir verbosityPavel Shilovsky
commit dcd87838c06f05ab7650b249ebf0d5b57ae63e1e upstream. Downgrade the loglevel for SMB2 to prevent filling the log with messages if e.g. readdir was interrupted. Also make SMB2 and SMB1 codepaths do the same logging during readdir. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAILNeilBrown
commit 9fa4eb8e490a28de40964b1b0e583d8db4c7e57c upstream. If a positive status is passed with the AUTOFS_DEV_IOCTL_FAIL ioctl, autofs4_d_automount() will return ERR_PTR(status) with that status to follow_automount(), which will then dereference an invalid pointer. So treat a positive status the same as zero, and map to ENOENT. See comment in systemd src/core/automount.c::automount_send_ready(). Link: http://lkml.kernel.org/r/871sqwczx5.fsf@notabene.neil.brown.name Signed-off-by: NeilBrown <neilb@suse.com> Cc: Ian Kent <raven@themaw.net> 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>
2017-06-29fs/exec.c: account for argv/envp pointersKees Cook
commit 98da7d08850fb8bdeb395d6368ed15753304aa0c upstream. When limiting the argv/envp strings during exec to 1/4 of the stack limit, the storage of the pointers to the strings was not included. This means that an exec with huge numbers of tiny strings could eat 1/4 of the stack limit in strings and then additional space would be later used by the pointers to the strings. For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721 single-byte strings would consume less than 2MB of stack, the max (8MB / 4) amount allowed, but the pointers to the strings would consume the remaining additional stack space (1677721 * 4 == 6710884). The result (1677721 + 6710884 == 8388605) would exhaust stack space entirely. Controlling this stack exhaustion could result in pathological behavior in setuid binaries (CVE-2017-1000365). [akpm@linux-foundation.org: additional commenting from Kees] Fixes: b6a2fea39318 ("mm: variable length argument support") Link: http://lkml.kernel.org/r/20170622001720.GA32173@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Qualys Security Advisory <qsa@qualys.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>
2017-06-26mm: larger stack guard gap, between vmasHugh Dickins
commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [wt: backport to 4.11: adjust context] [wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide] [wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes] Signed-off-by: Willy Tarreau <w@1wt.eu> [gkh: minor build fixes for 4.4] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-26configfs: Fix race between create_link and configfs_rmdirNicholas Bellinger
commit ba80aa909c99802c428682c352b0ee0baac0acd3 upstream. This patch closes a long standing race in configfs between the creation of a new symlink in create_link(), while the symlink target's config_item is being concurrently removed via configfs_rmdir(). This can happen because the symlink target's reference is obtained by config_item_get() in create_link() before the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep() during configfs_rmdir() shutdown is actually checked.. This originally manifested itself on ppc64 on v4.8.y under heavy load using ibmvscsi target ports with Novalink API: [ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added [ 7879.893760] ------------[ cut here ]------------ [ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs] [ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G O 4.8.17-customv2.22 #12 [ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000 [ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870 [ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700 Tainted: G O (4.8.17-customv2.22) [ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 28222242 XER: 00000000 [ 7879.893820] CFAR: d000000002c664bc SOFTE: 1 GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820 GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000 GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80 GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40 GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940 GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000 GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490 GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940 [ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs] [ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893842] Call Trace: [ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460 [ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490 [ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170 [ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390 [ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec [ 7879.893856] Instruction dump: [ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000 [ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000 [ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]--- To close this race, go ahead and obtain the symlink's target config_item reference only after the existing CONFIGFS_USET_DROPPING check succeeds. This way, if configfs_rmdir() wins create_link() will return -ENONET, and if create_link() wins configfs_rmdir() will return -EBUSY. Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-17proc: add a schedule point in proc_pid_readdir()Eric Dumazet
[ Upstream commit 3ba4bceef23206349d4130ddf140819b365de7c8 ] We have seen proc_pid_readdir() invocations holding cpu for more than 50 ms. Add a cond_resched() to be gentle with other tasks. [akpm@linux-foundation.org: coding style fix] Link: http://lkml.kernel.org/r/1484238380.15816.42.camel@edumazet-glaptop3.roam.corp.google.com Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-25 04:48:09 +0000