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2018-10-10sysfs: Do not return POSIX ACL xattrs via listxattrAndreas Gruenbacher
commit ffc4c92227db5699493e43eb140b4cb5904c30ff upstream. Commit 786534b92f3c introduced a regression that caused listxattr to return the POSIX ACL attribute names even though sysfs doesn't support POSIX ACLs. This happens because simple_xattr_list checks for NULL i_acl / i_default_acl, but inode_init_always initializes those fields to ACL_NOT_CACHED ((void *)-1). For example: $ getfattr -m- -d /sys /sys: system.posix_acl_access: Operation not supported /sys: system.posix_acl_default: Operation not supported Fix this in simple_xattr_list by checking if the filesystem supports POSIX ACLs. Fixes: 786534b92f3c ("tmpfs: listxattr should include POSIX ACL xattrs") Reported-by: Marc Aurèle La France <tsi@tuyoix.net> Tested-by: Marc Aurèle La France <tsi@tuyoix.net> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-09getxattr: use correct xattr lengthChristian Brauner
commit 82c9a927bc5df6e06b72d206d24a9d10cced4eb5 upstream. When running in a container with a user namespace, if you call getxattr with name = "system.posix_acl_access" and size % 8 != 4, then getxattr silently skips the user namespace fixup that it normally does resulting in un-fixed-up data being returned. This is caused by posix_acl_fix_xattr_to_user() being passed the total buffer size and not the actual size of the xattr as returned by vfs_getxattr(). This commit passes the actual length of the xattr as returned by vfs_getxattr() down. A reproducer for the issue is: touch acl_posix setfacl -m user:0:rwx acl_posix and the compile: #define _GNU_SOURCE #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <unistd.h> #include <attr/xattr.h> /* Run in user namespace with nsuid 0 mapped to uid != 0 on the host. */ int main(int argc, void **argv) { ssize_t ret1, ret2; char buf1[128], buf2[132]; int fret = EXIT_SUCCESS; char *file; if (argc < 2) { fprintf(stderr, "Please specify a file with " "\"system.posix_acl_access\" permissions set\n"); _exit(EXIT_FAILURE); } file = argv[1]; ret1 = getxattr(file, "system.posix_acl_access", buf1, sizeof(buf1)); if (ret1 < 0) { fprintf(stderr, "%s - Failed to retrieve " "\"system.posix_acl_access\" " "from \"%s\"\n", strerror(errno), file); _exit(EXIT_FAILURE); } ret2 = getxattr(file, "system.posix_acl_access", buf2, sizeof(buf2)); if (ret2 < 0) { fprintf(stderr, "%s - Failed to retrieve " "\"system.posix_acl_access\" " "from \"%s\"\n", strerror(errno), file); _exit(EXIT_FAILURE); } if (ret1 != ret2) { fprintf(stderr, "The value of \"system.posix_acl_" "access\" for file \"%s\" changed " "between two successive calls\n", file); _exit(EXIT_FAILURE); } for (ssize_t i = 0; i < ret2; i++) { if (buf1[i] == buf2[i]) continue; fprintf(stderr, "Unexpected different in byte %zd: " "%02x != %02x\n", i, buf1[i], buf2[i]); fret = EXIT_FAILURE; } if (fret == EXIT_SUCCESS) fprintf(stderr, "Test passed\n"); else fprintf(stderr, "Test failed\n"); _exit(fret); } and run: ./tester acl_posix On a non-fixed up kernel this should return something like: root@c1:/# ./t Unexpected different in byte 16: ffffffa0 != 00 Unexpected different in byte 17: ffffff86 != 00 Unexpected different in byte 18: 01 != 00 and on a fixed kernel: root@c1:~# ./t Test passed Cc: stable@vger.kernel.org Fixes: 2f6f0654ab61 ("userns: Convert vfs posix_acl support to use kuids and kgids") Link: https://bugzilla.kernel.org/show_bug.cgi?id=199945 Reported-by: Colin Watson <cjwatson@ubuntu.com> Signed-off-by: Christian Brauner <christian@brauner.io> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12lsm: fix smack_inode_removexattr and xattr_getsecurity memleakCasey Schaufler
commit 57e7ba04d422c3d41c8426380303ec9b7533ded9 upstream. security_inode_getsecurity() provides the text string value of a security attribute. It does not provide a "secctx". The code in xattr_getsecurity() that calls security_inode_getsecurity() and then calls security_release_secctx() happened to work because SElinux and Smack treat the attribute and the secctx the same way. It fails for cap_inode_getsecurity(), because that module has no secctx that ever needs releasing. It turns out that Smack is the one that's doing things wrong by not allocating memory when instructed to do so by the "alloc" parameter. The fix is simple enough. Change the security_release_secctx() to kfree() because it isn't a secctx being returned by security_inode_getsecurity(). Change Smack to allocate the string when told to do so. Note: this also fixes memory leaks for LSMs which implement inode_getsecurity but not release_secctx, such as capabilities. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-20fs/xattr.c: zero out memory copied to userspace in getxattrMichal Hocko
commit 81be3dee96346fbe08c31be5ef74f03f6b63cf68 upstream. getxattr uses vmalloc to allocate memory if kzalloc fails. This is filled by vfs_getxattr and then copied to the userspace. vmalloc, however, doesn't zero out the memory so if the specific implementation of the xattr handler is sloppy we can theoretically expose a kernel memory. There is no real sign this is really the case but let's make sure this will not happen and use vzalloc instead. Fixes: 779302e67835 ("fs/xattr.c:getxattr(): improve handling of allocation failures") Link: http://lkml.kernel.org/r/20170306103327.2766-1-mhocko@kernel.org Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Michal Hocko <mhocko@suse.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>
2016-11-17xattr: Fix setting security xattrs on sockfsAndreas Gruenbacher
The IOP_XATTR flag is set on sockfs because sockfs supports getting the "system.sockprotoname" xattr. Since commit 6c6ef9f2, this flag is checked for setxattr support as well. This is wrong on sockfs because security xattr support there is supposed to be provided by security_inode_setsecurity. The smack security module relies on socket labels (xattrs). Fix this by adding a security xattr handler on sockfs that returns -EAGAIN, and by checking for -EAGAIN in setxattr. We cannot simply check for -EOPNOTSUPP in setxattr because there are filesystems that neither have direct security xattr support nor support via security_inode_setsecurity. A more proper fix might be to move the call to security_inode_setsecurity into sockfs, but it's not clear to me if that is safe: we would end up calling security_inode_post_setxattr after that as well. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07vfs: Remove {get,set,remove}xattr inode operationsAndreas Gruenbacher
These inode operations are no longer used; remove them. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07xattr: Stop calling {get,set,remove}xattr inode operationsAndreas Gruenbacher
All filesystems that support xattrs by now do so via xattr handlers. They all define sb->s_xattr, and their getxattr, setxattr, and removexattr inode operations use the generic inode operations. On filesystems that don't support xattrs, the xattr inode operations are all NULL, and sb->s_xattr is also NULL. This means that we can remove the getxattr, setxattr, and removexattr inode operations and directly call the generic handlers, or better, inline expand those handlers into fs/xattr.c. Filesystems that do not support xattrs on some inodes should clear the IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems have checks to disable xattrs on some inodes in the ->list, ->get, and ->set xattr handler operations instead.) The IOP_XATTR flag is automatically cleared in inodes of filesystems that don't have xattr support. In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a check for symlinks to orangefs_inode_getxattr to preserve the current, weird behavior; that check may not be necessary though. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07vfs: Check for the IOP_XATTR flag in listxattrAndreas Gruenbacher
When an inode doesn't support xattrs, turn listxattr off as well. (When xattrs are "turned off", the VFS still passes security xattr operations through to security modules, which can still expose inode security labels that way.) Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07xattr: Add __vfs_{get,set,remove}xattr helpersAndreas Gruenbacher
Right now, various places in the kernel check for the existence of getxattr, setxattr, and removexattr inode operations and directly call those operations. Switch to helper functions and test for the IOP_XATTR flag instead. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07vfs: Use IOP_XATTR flag for bad-inode handlingAndreas Gruenbacher
With this change, all the xattr handler based operations will produce an -EIO result for bad inodes, and we no longer only depend on inode->i_op to be set to bad_inode_ops. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07vfs: Add IOP_XATTR inode operations flagAndreas Gruenbacher
The IOP_XATTR inode operations flag in inode->i_opflags indicates that the inode has xattr support. The flag is automatically set by new_inode() on filesystems with xattr support (where sb->s_xattr is defined), and cleared otherwise. Filesystems can explicitly clear it for inodes that should not have xattr support. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07vfs: Move xattr_resolve_name to the front of fs/xattr.cAndreas Gruenbacher
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-06xattr: Remove unnecessary NULL attribute name checkAndreas Gruenbacher
When NULL is passed to one of the xattr system calls as the attribute name, copying that name from user space already fails with -EFAULT; xattr_resolve_name is never called with a NULL attribute name. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-05vfs: Don't modify inodes with a uid or gid unknown to the vfsEric W. Biederman
When a filesystem outside of init_user_ns is mounted it could have uids and gids stored in it that do not map to init_user_ns. The plan is to allow those filesystems to set i_uid to INVALID_UID and i_gid to INVALID_GID for unmapped uids and gids and then to handle that strange case in the vfs to ensure there is consistent robust handling of the weirdness. Upon a careful review of the vfs and filesystems about the only case where there is any possibility of confusion or trouble is when the inode is written back to disk. In that case filesystems typically read the inode->i_uid and inode->i_gid and write them to disk even when just an inode timestamp is being updated. Which leads to a rule that is very simple to implement and understand inodes whose i_uid or i_gid is not valid may not be written. In dealing with access times this means treat those inodes as if the inode flag S_NOATIME was set. Reads of the inodes appear safe and useful, but any write or modification is disallowed. The only inode write that is allowed is a chown that sets the uid and gid on the inode to valid values. After such a chown the inode is normal and may be treated as such. Denying all writes to inodes with uids or gids unknown to the vfs also prevents several oddball cases where corruption would have occurred because the vfs does not have complete information. One problem case that is prevented is attempting to use the gid of a directory for new inodes where the directories sgid bit is set but the directories gid is not mapped. Another problem case avoided is attempting to update the evm hash after setxattr, removexattr, and setattr. As the evm hash includeds the inode->i_uid or inode->i_gid not knowning the uid or gid prevents a correct evm hash from being computed. evm hash verification also fails when i_uid or i_gid is unknown but that is essentially harmless as it does not cause filesystem corruption. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-05-27switch ->setxattr() to passing dentry and inode separatelyAl Viro
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before we'd hashed the new dentry and attached it to inode, we need ->setxattr() instances getting the inode as an explicit argument rather than obtaining it from dentry. Similar change for ->getxattr() had been done in commit ce23e64. Unlike ->getxattr() (which is used by both selinux and smack instances of ->d_instantiate()) ->setxattr() is used only by smack one and unfortunately it got missed back then. Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-27switch xattr_handler->set() to passing dentry and inode separatelyAl Viro
preparation for similar switch in ->setxattr() (see the next commit for rationale). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-25make xattr_resolve_handlers() safe to use with NULL ->s_xattrAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-25xattr: Fail with -EINVAL for NULL attribute namesAndreas Gruenbacher
Commit 98e9cb57 improved the xattr name checks in xattr_resolve_name but didn't update the NULL attribute name check appropriately, so NULL attribute names lead to NULL pointer dereferences. Turn that into -EINVAL results instead. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> fs/xattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-11->getxattr(): pass dentry and inode as separate argumentsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-10xattr_handler: pass dentry and inode as separate arguments of ->get()Al Viro
... and do not assume they are already attached to each other Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-02-20xattr handlers: plug a lock leak in simple_xattr_listMateusz Guzik
The code could leak xattrs->lock on error. Problem introduced with 786534b92f3ce68f4 "tmpfs: listxattr should include POSIX ACL xattrs". Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22wrappers for ->i_mutex accessAl Viro
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-12Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "All kinds of stuff. That probably should've been 5 or 6 separate branches, but by the time I'd realized how large and mixed that bag had become it had been too close to -final to play with rebasing. Some fs/namei.c cleanups there, memdup_user_nul() introduction and switching open-coded instances, burying long-dead code, whack-a-mole of various kinds, several new helpers for ->llseek(), assorted cleanups and fixes from various people, etc. One piece probably deserves special mention - Neil's lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets called without ->i_mutex and tries to avoid ever taking it. That, of course, means that it's not useful for any directory modifications, but things like getting inode attributes in nfds readdirplus are fine with that. I really should've asked for moratorium on lookup-related changes this cycle, but since I hadn't done that early enough... I *am* asking for that for the coming cycle, though - I'm going to try and get conversion of i_mutex to rwsem with ->lookup() done under lock taken shared. There will be a patch closer to the end of the window, along the lines of the one Linus had posted last May - mechanical conversion of ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/ inode_is_locked()/inode_lock_nested(). To quote Linus back then: ----- | This is an automated patch using | | sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/' | sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/' | sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/' | sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/' | sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/' | | with a very few manual fixups ----- I'm going to send that once the ->i_mutex-affecting stuff in -next gets mostly merged (or when Linus says he's about to stop taking merges)" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) nfsd: don't hold i_mutex over userspace upcalls fs:affs:Replace time_t with time64_t fs/9p: use fscache mutex rather than spinlock proc: add a reschedule point in proc_readfd_common() logfs: constify logfs_block_ops structures fcntl: allow to set O_DIRECT flag on pipe fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE fs: xattr: Use kvfree() [s390] page_to_phys() always returns a multiple of PAGE_SIZE nbd: use ->compat_ioctl() fs: use block_device name vsprintf helper lib/vsprintf: add %*pg format specifier fs: use gendisk->disk_name where possible poll: plug an unused argument to do_poll amdkfd: don't open-code memdup_user() cdrom: don't open-code memdup_user() rsxx: don't open-code memdup_user() mtip32xx: don't open-code memdup_user() [um] mconsole: don't open-code memdup_user_nul() [um] hostaudio: don't open-code memdup_user() ...
2016-01-09fs: xattr: Use kvfree()Richard Weinberger
... instead of open coding it. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-13xattr handlers: Simplify list operationAndreas Gruenbacher
Change the list operation to only return whether or not an attribute should be listed. Copying the attribute names into the buffer is moved to the callers. Since the result only depends on the dentry and not on the attribute name, we do not pass the attribute name to list operations. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-13nfs: Move call to security_inode_listsecurity into nfs_listxattrAndreas Gruenbacher
Add a nfs_listxattr operation. Move the call to security_inode_listsecurity from list operation of the "security.*" xattr handler to nfs_listxattr. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Anna Schumaker <anna.schumaker@netapp.com> Cc: linux-nfs@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06tmpfs: listxattr should include POSIX ACL xattrsAndreas Gruenbacher
When a file on tmpfs has an ACL or a Default ACL, listxattr should include the corresponding xattr name. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06tmpfs: Use xattr handler infrastructureAndreas Gruenbacher
Use the VFS xattr handler infrastructure and get rid of similar code in the filesystem. For implementing shmem_xattr_handler_set, we need a version of simple_xattr_set which removes the attribute when value is NULL. Use this to implement kernfs_iop_removexattr as well. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06vfs: Distinguish between full xattr names and proper prefixesAndreas Gruenbacher
Add an additional "name" field to struct xattr_handler. When the name is set, the handler matches attributes with exactly that name. When the prefix is set instead, the handler matches attributes with the given prefix and with a non-empty suffix. This patch should avoid bugs like the one fixed in commit c361016a in the future. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06vfs: Remove vfs_xattr_cmpAndreas Gruenbacher
This function was only briefly used in security/integrity/evm, between commits 66dbc325 and 15647eb3. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-139p: xattr simplificationsAndreas Gruenbacher
Now that the xattr handler is passed to the xattr handler operations, we can use the same get and set operations for the user, trusted, and security xattr namespaces. In those namespaces, we can access the full attribute name by "reattaching" the name prefix the vfs has skipped for us. Add a xattr_full_name helper to make this obvious in the code. For the "system.posix_acl_access" and "system.posix_acl_default" attributes, handler->prefix is the full attribute name; the suffix is the empty string. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: v9fs-developer@lists.sourceforge.net Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-13xattr handlers: Pass handler to operations instead of flagsAndreas Gruenbacher
The xattr_handler operations are currently all passed a file system specific flags value which the operations can use to disambiguate between different handlers; some file systems use that to distinguish the xattr namespace, for example. In some oprations, it would be useful to also have access to the handler prefix. To allow that, pass a pointer to the handler to operations instead of the flags value alone. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-21evm: fix potential race when removing xattrsDmitry Kasatkin
EVM needs to be atomically updated when removing xattrs. Otherwise concurrent EVM verification may fail in between. This patch fixes by moving i_mutex unlocking after calling EVM hook. fsnotify_xattr() is also now called while locked the same way as it is done in __vfs_setxattr_noperm. Changelog: - remove unused 'inode' variable. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-19new helper: audit_file()Al Viro
... for situations when we don't have any candidate in pathnames - basically, in descriptor-based syscalls. [Folded the build fix for !CONFIG_AUDITSYSCALL configs from Chen Gang] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-12vfs: Deduplicate code shared by xattr system calls operating on pathsEric Biggers
The following pairs of system calls dealing with extended attributes only differ in their behavior on whether the symbolic link is followed (when the named file is a symbolic link): - setxattr() and lsetxattr() - getxattr() and lgetxattr() - listxattr() and llistxattr() - removexattr() and lremovexattr() Despite this, the implementations all had duplicated code, so this commit redirects each of the above pairs of system calls to a corresponding function to which different lookup flags (LOOKUP_FOLLOW or 0) are passed. For me this reduced the stripped size of xattr.o from 8824 to 8248 bytes. Signed-off-by: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-07-23simple_xattr: permit 0-size extended attributesHugh Dickins
If a filesystem uses simple_xattr to support user extended attributes, LTP setxattr01 and xfstests generic/062 fail with "Cannot allocate memory": simple_xattr_alloc()'s wrap-around test mistakenly excludes values of zero size. Fix that off-by-one (but apparently no filesystem needs them yet). Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: Aristeu Rozanski <aris@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20vfs: make lremovexattr retry once on ESTALE errorJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20vfs: make removexattr retry once on ESTALEJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20vfs: make llistxattr retry once on ESTALE errorJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20vfs: make listxattr retry once on ESTALE errorJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20vfs: make lgetxattr retry once on ESTALEJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20vfs: make getxattr retry once on an ESTALE errorJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20vfs: allow lsetxattr() to retry once on ESTALE errorsJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-20vfs: allow setxattr to retry once on ESTALE errorsJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-18fs, xattr: fix bug when removing a name not in xattr listDavid Rientjes
Commit 38f38657444d ("xattr: extract simple_xattr code from tmpfs") moved some code from tmpfs but introduced a subtle bug along the way. If the name passed to simple_xattr_remove() does not exist in the list of xattrs, then it is possible to call kfree(new_xattr) when new_xattr is actually initialized to itself on the stack via uninitialized_var(). This causes a BUG() since the memory was not allocated via the slab allocator and was not bypassed through to the page allocator because it was too large. Initialize the local variable to NULL so the kfree() never takes place. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-12audit: set the name_len in audit_inode for parent lookupsJeff Layton
Currently, this gets set mostly by happenstance when we call into audit_inode_child. While that might be a little more efficient, it seems wrong. If the syscall ends up failing before audit_inode_child ever gets called, then you'll have an audit_names record that shows the full path but has the parent inode info attached. Fix this by passing in a parent flag when we call audit_inode that gets set to the value of LOOKUP_PARENT. We can then fix up the pathname for the audit entry correctly from the get-go. While we're at it, clean up the no-op macro for audit_inode in the !CONFIG_AUDITSYSCALL case. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-02Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: - Integrity: add local fs integrity verification to detect offline attacks - Integrity: add digital signature verification - Simple stacking of Yama with other LSMs (per LSS discussions) - IBM vTPM support on ppc64 - Add new driver for Infineon I2C TIS TPM - Smack: add rule revocation for subject labels" Fixed conflicts with the user namespace support in kernel/auditsc.c and security/integrity/ima/ima_policy.c. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (39 commits) Documentation: Update git repository URL for Smack userland tools ima: change flags container data type Smack: setprocattr memory leak fix Smack: implement revoking all rules for a subject label Smack: remove task_wait() hook. ima: audit log hashes ima: generic IMA action flag handling ima: rename ima_must_appraise_or_measure audit: export audit_log_task_info tpm: fix tpm_acpi sparse warning on different address spaces samples/seccomp: fix 31 bit build on s390 ima: digital signature verification support ima: add support for different security.ima data types ima: add ima_inode_setxattr/removexattr function and calls ima: add inode_post_setattr call ima: replace iint spinblock with rwlock/read_lock ima: allocating iint improvements ima: add appraise action keywords and default rules ima: integrity appraisal extension vfs: move ima_file_free before releasing the file ...
2012-10-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs update from Al Viro: - big one - consolidation of descriptor-related logics; almost all of that is moved to fs/file.c (BTW, I'm seriously tempted to rename the result to fd.c. As it is, we have a situation when file_table.c is about handling of struct file and file.c is about handling of descriptor tables; the reasons are historical - file_table.c used to be about a static array of struct file we used to have way back). A lot of stray ends got cleaned up and converted to saner primitives, disgusting mess in android/binder.c is still disgusting, but at least doesn't poke so much in descriptor table guts anymore. A bunch of relatively minor races got fixed in process, plus an ext4 struct file leak. - related thing - fget_light() partially unuglified; see fdget() in there (and yes, it generates the code as good as we used to have). - also related - bits of Cyrill's procfs stuff that got entangled into that work; _not_ all of it, just the initial move to fs/proc/fd.c and switch of fdinfo to seq_file. - Alex's fs/coredump.c spiltoff - the same story, had been easier to take that commit than mess with conflicts. The rest is a separate pile, this was just a mechanical code movement. - a few misc patches all over the place. Not all for this cycle, there'll be more (and quite a few currently sit in akpm's tree)." Fix up trivial conflicts in the android binder driver, and some fairly simple conflicts due to two different changes to the sock_alloc_file() interface ("take descriptor handling from sock_alloc_file() to callers" vs "net: Providing protocol type via system.sockprotoname xattr of /proc/PID/fd entries" adding a dentry name to the socket) * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits) MAX_LFS_FILESIZE should be a loff_t compat: fs: Generic compat_sys_sendfile implementation fs: push rcu_barrier() from deactivate_locked_super() to filesystems btrfs: reada_extent doesn't need kref for refcount coredump: move core dump functionality into its own file coredump: prevent double-free on an error path in core dumper usb/gadget: fix misannotations fcntl: fix misannotations ceph: don't abuse d_delete() on failure exits hypfs: ->d_parent is never NULL or negative vfs: delete surplus inode NULL check switch simple cases of fget_light to fdget new helpers: fdget()/fdput() switch o2hb_region_dev_write() to fget_light() proc_map_files_readdir(): don't bother with grabbing files make get_file() return its argument vhost_set_vring(): turn pollstart/pollstop into bool switch prctl_set_mm_exe_file() to fget_light() switch xfs_find_handle() to fget_light() switch xfs_swapext() to fget_light() ...
2012-10-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace changes from Eric Biederman: "This is a mostly modest set of changes to enable basic user namespace support. This allows the code to code to compile with user namespaces enabled and removes the assumption there is only the initial user namespace. Everything is converted except for the most complex of the filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs, nfs, ocfs2 and xfs as those patches need a bit more review. The strategy is to push kuid_t and kgid_t values are far down into subsystems and filesystems as reasonable. Leaving the make_kuid and from_kuid operations to happen at the edge of userspace, as the values come off the disk, and as the values come in from the network. Letting compile type incompatible compile errors (present when user namespaces are enabled) guide me to find the issues. The most tricky areas have been the places where we had an implicit union of uid and gid values and were storing them in an unsigned int. Those places were converted into explicit unions. I made certain to handle those places with simple trivial patches. Out of that work I discovered we have generic interfaces for storing quota by projid. I had never heard of the project identifiers before. Adding full user namespace support for project identifiers accounts for most of the code size growth in my git tree. Ultimately there will be work to relax privlige checks from "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing root in a user names to do those things that today we only forbid to non-root users because it will confuse suid root applications. While I was pushing kuid_t and kgid_t changes deep into the audit code I made a few other cleanups. I capitalized on the fact we process netlink messages in the context of the message sender. I removed usage of NETLINK_CRED, and started directly using current->tty. Some of these patches have also made it into maintainer trees, with no problems from identical code from different trees showing up in linux-next. After reading through all of this code I feel like I might be able to win a game of kernel trivial pursuit." Fix up some fairly trivial conflicts in netfilter uid/git logging code. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits) userns: Convert the ufs filesystem to use kuid/kgid where appropriate userns: Convert the udf filesystem to use kuid/kgid where appropriate userns: Convert ubifs to use kuid/kgid userns: Convert squashfs to use kuid/kgid where appropriate userns: Convert reiserfs to use kuid and kgid where appropriate userns: Convert jfs to use kuid/kgid where appropriate userns: Convert jffs2 to use kuid and kgid where appropriate userns: Convert hpfs to use kuid and kgid where appropriate userns: Convert btrfs to use kuid/kgid where appropriate userns: Convert bfs to use kuid/kgid where appropriate userns: Convert affs to use kuid/kgid wherwe appropriate userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids userns: On ia64 deal with current_uid and current_gid being kuid and kgid userns: On ppc convert current_uid from a kuid before printing. userns: Convert s390 getting uid and gid system calls to use kuid and kgid userns: Convert s390 hypfs to use kuid and kgid where appropriate userns: Convert binder ipc to use kuids userns: Teach security_path_chown to take kuids and kgids userns: Add user namespace support to IMA userns: Convert EVM to deal with kuids and kgids in it's hmac computation ...
2012-09-26switch simple cases of fget_light to fdgetAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>