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* fuse: initialize the flock flag in fuse_file on allocationMateusz Jurczyk2017-11-111-1/+1
| | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* sched: move no_new_privs into new atomic flagsKees Cook2017-10-121-2/+2
| | | | | | | | | | | | | | | commit 1d4457f99928a968767f6405b4a1f50845aa15fd upstream. Since seccomp transitions between threads requires updates to the no_new_privs flag to be atomic, the flag must be part of an atomic flag set. This moves the nnp flag into a separate task field, and introduces accessors. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Andy Lutomirski <luto@amacapital.net> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Fix match_prepath()Sachin Prabhu2017-10-121-8/+6
| | | | | | | | | | | | | | commit cd8c42968ee651b69e00f8661caff32b0086e82d upstream. Incorrect return value for shares not using the prefix path means that we will never match superblocks for these shares. Fixes: commit c1d8b24d1819 ("Compare prepaths when comparing superblocks") Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com> Cc: Aurélien Aptel <aaptel@suse.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Fix regression which breaks DFS mountingSachin Prabhu2017-10-121-6/+8
| | | | | | | | | | | | commit d171356ff11ab1825e456dfb979755e01b3c54a1 upstream. Patch a6b5058 results in -EREMOTE returned by is_path_accessible() in cifs_mount() to be ignored which breaks DFS mounting. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Move check for prefix path to within cifs_get_root()Sachin Prabhu2017-10-121-5/+4
| | | | | | | | | commit 348c1bfa84dfc47da1f1234b7f2bf09fa798edea upstream. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Tested-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Compare prepaths when comparing superblocksSachin Prabhu2017-10-121-1/+20
| | | | | | | | | | | | | | | | | | commit c1d8b24d18192764fe82067ec6aa8d4c3bf094e0 upstream. The patch fs/cifs: make share unaccessible at root level mountable makes use of prepaths when any component of the underlying path is inaccessible. When mounting 2 separate shares having different prepaths but are other wise similar in other respects, we end up sharing superblocks when we shouldn't be doing so. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Tested-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Fix memory leaks in cifs_do_mount()Sachin Prabhu2017-10-123-14/+18
| | | | | | | | | | | | | | | commit 4214ebf4654798309364d0c678b799e402f38288 upstream. Fix memory leaks introduced by the patch fs/cifs: make share unaccessible at root level mountable Also move allocation of cifs_sb->prepath to cifs_setup_cifs_sb(). Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Tested-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <smfrench@gmail.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* fs/cifs: make share unaccessible at root level mountableAurelien Aptel2017-10-125-5/+104
| | | | | | | | | | | | | | | | | | | | | | commit a6b5058fafdf508904bbf16c29b24042cef3c496 upstream. if, when mounting //HOST/share/sub/dir/foo we can query /sub/dir/foo but not any of the path components above: - store the /sub/dir/foo prefix in the cifs super_block info - in the superblock, set root dentry to the subpath dentry (instead of the share root) - set a flag in the superblock to remember it - use prefixpath when building path from a dentry fixes bso#8950 Signed-off-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com> [bwh: Backported to 3.16: use Jiri Slaby's backport of the change in cifs_root_iget()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Btrfs: don't use src fd for printkJosef Bacik2017-10-121-1/+1
| | | | | | | | | | | | | commit c79b4713304f812d3d6c95826fc3e5fc2c0b0c14 upstream. The fd we pass in may not be on a btrfs file system, so don't try to do BTRFS_I() on it. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* xfs: XFS_IS_REALTIME_INODE() should be false if no rt device presentRichard Wareing2017-10-121-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* btrfs: preserve i_mode if __btrfs_set_acl() failsErnesto A. Fernández2017-10-121-1/+5
| | | | | | | | | | | | | | | | | | | | | commit d7d824966530acfe32b94d1ed672e6fe1638cd68 upstream. When changing a file's acl mask, btrfs_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by restoring the original mode bits if __btrfs_set_acl fails. Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* f2fs: preserve i_mode if __f2fs_set_acl() failsErnesto A. Fernández2017-10-121-2/+3
| | | | | | | | | | | | | | | | | | | | | commit 14af20fcb1833dd776822361891963c90f7b0262 upstream. When changing a file's acl mask, __f2fs_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* f2fs: Don't clear SGID when inheriting ACLsJaegeuk Kim2017-10-121-1/+1
| | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* ext4: Don't clear SGID when inheriting ACLsJan Kara2017-10-121-13/+15
| | | | | | | | | | | | | | | | | | | | | | | | | commit a3bb2d5587521eea6dab2d05326abb0afb460abd upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving posix_acl_update_mode() out of __ext4_set_acl() into ext4_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> [bwh: Backported to 3.16: - Keep using ext4_current_time() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ext4: preserve i_mode if __ext4_set_acl() failsErnesto A. Fernández2017-10-121-4/+11
| | | | | | | | | | | | | | | | | | | | | commit 397e434176bb62bc6068d2210af1d876c6212a7e upstream. When changing a file's acl mask, __ext4_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: keep using ext4_current_time()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* jfs: preserve i_mode if __jfs_set_acl() failsErnesto A. Fernández2017-10-121-4/+11
| | | | | | | | | | | | | | | | | | | | commit f070e5ac9bc7de71c34402048ce5526dccbd347c upstream. When changing a file's acl mask, __jfs_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> [bwh: Backported to 3.16: keep using CURRENT_TIME] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* jfs: Don't clear SGID when inheriting ACLsJan Kara2017-10-121-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | commit 9bcf66c72d726322441ec82962994e69157613e4 upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving posix_acl_update_mode() out of __jfs_set_acl() into jfs_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: jfs-discussion@lists.sourceforge.net Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> [bwh: Backported to 3.16: - Keep using CURRENT_TIME - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* reiserfs: preserve i_mode if __reiserfs_set_acl() failsErnesto A. Fernández2017-10-121-3/+6
| | | | | | | | | | | | | | | | | | | commit fcea8aed91f53b51f9b943dc01f12d8aa666c720 upstream. When changing a file's acl mask, reiserfs_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* reiserfs: Don't clear SGID when inheriting ACLsJan Kara2017-10-121-5/+7
| | | | | | | | | | | | | | | | | | | | | | commit 6883cd7f68245e43e91e5ee583b7550abf14523f upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving posix_acl_update_mode() out of __reiserfs_set_acl() into reiserfs_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: reiserfs-devel@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* hfsplus: Don't clear SGID when inheriting ACLsJan Kara2017-10-121-12/+18
| | | | | | | | | | | | | | | | | | | | commit 84969465ddc4f8aeb3b993123b571aa01c5f2683 upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by creating __hfsplus_set_posix_acl() function that does not call posix_acl_update_mode() and use it when inheriting ACLs. That prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ext3: preserve i_mode if ext2_set_acl() failsBen Hutchings2017-10-121-2/+8
| | | | | | | | | | | | | | | | | | | | Based on Ernesto A. Fernández's fix for ext2 (commit fe26569eb919), from which the following description is taken: > When changing a file's acl mask, ext2_set_acl() will first set the group > bits of i_mode to the value of the mask, and only then set the actual > extended attribute representing the new acl. > > If the second part fails (due to lack of space, for example) and the file > had no acl attribute to begin with, the system will from now on assume > that the mask permission bits are actual group permission bits, potentially > granting access to the wrong users. > > Prevent this by only changing the inode mode after the acl has been set. Cc: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ext3: Don't clear SGID when inheriting ACLsBen Hutchings2017-10-121-7/+8
| | | | | | | | | | | | | | | | | | | Based on Jan Kara's fix for ext2 (commit a992f2d38e4c), from which the following description is taken: > When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit > set, DIR1 is expected to have SGID bit set (and owning group equal to > the owning group of 'DIR0'). However when 'DIR0' also has some default > ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on > 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving the posix_acl_update_mode() call up from __ext3_set_acl() into ext3_set_acl(). Fixes: 073931017b49 ("posix_acl: Clear SGID bit when setting file permissions") Cc: linux-ext4@vger.kernel.org Cc: Jan Kara <jack@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ext2: preserve i_mode if ext2_set_acl() failsErnesto A. Fernández2017-10-121-2/+9
| | | | | | | | | | | | | | | | | | | | | commit fe26569eb9197d845d73abe7dd20f603d79eb031 upstream. When changing a file's acl mask, ext2_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. [JK: Rebased on top of "ext2: Don't clear SGID when inheriting ACLs"] Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ext2: Don't clear SGID when inheriting ACLsJan Kara2017-10-121-14/+22
| | | | | | | | | | | | | | | | | | | | | commit a992f2d38e4ce17b8c7d1f7f67b2de0eebdea069 upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by creating __ext2_set_acl() function that does not call posix_acl_update_mode() and use it when inheriting ACLs. That prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: linux-ext4@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: keep using CURRENT_TIME_SEC] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ubifs: Don't leak kernel memory to the MTDRichard Weinberger2017-10-121-4/+4
| | | | | | | | | | | | | | | | | | | | | commit 4acadda74ff8b949c448c0282765ae747e088c87 upstream. When UBIFS prepares data structures which will be written to the MTD it ensues that their lengths are multiple of 8. Since it uses kmalloc() the padded bytes are left uninitialized and we leak a few bytes of kernel memory to the MTD. To make sure that all bytes are initialized, let's switch to kzalloc(). Kzalloc() is fine in this case because the buffers are not huge and in the IO path the performance bottleneck is anyway the MTD. Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Richard Weinberger <richard@nod.at> [bwh: Backported to 3.16: - Drop change in ubifs_jnl_xrename() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ubifs: Correctly evict xattr inodesRichard Weinberger2017-10-123-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 272eda8298dc82eb411ece82bbb2c62911087b24 upstream. UBIFS handles extended attributes just like files, as consequence of that, they also have inodes. Therefore UBIFS does all the inode machinery also for xattrs. Since new inodes have i_nlink of 1, a file or xattr inode will be evicted if i_nlink goes down to 0 after an unlink. UBIFS assumes this model also for xattrs, which is not correct. One can create a file "foo" with xattr "user.test". By reading "user.test" an inode will be created, and by deleting "user.test" it will get evicted later. The assumption breaks if the file "foo", which hosts the xattrs, will be removed. VFS nor UBIFS does not remove each xattr via ubifs_xattr_remove(), it just removes the host inode from the TNC and all underlying xattr nodes too and the inode will remain in the cache and wastes memory. To solve this problem, remove xattr inodes from the VFS inode cache in ubifs_xattr_remove() to make sure that they get evicted. Fixes: 1e51764a3c2ac05a ("UBIFS: add new flash file system") Signed-off-by: Richard Weinberger <richard@nod.at> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sysctl: fix lax sysctl_check_table() sanity checkLuis R. Rodriguez2017-10-121-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 89c5b53b16bf577079d4f0311406dbea3c71202c upstream. Patch series "sysctl: few fixes", v5. I've been working on making kmod more deterministic, and as I did that I couldn't help but notice a few issues with sysctl. My end goal was just to fix unsigned int support, which back then was completely broken. Liping Zhang has sent up small atomic fixes, however it still missed yet one more fix and Alexey Dobriyan had also suggested to just drop array support given its complexity. I have inspected array support using Coccinelle and indeed its not that popular, so if in fact we can avoid it for new interfaces, I agree its best. I did develop a sysctl stress driver but will hold that off for another series. This patch (of 5): Commit 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks") improved sanity checks considerbly, however the enhancements on sysctl_check_table() meant adding a functional change so that only the last table entry's sanity error is propagated. It also changed the way errors were propagated so that each new check reset the err value, this means only last sanity check computed is used for an error. This has been in the kernel since v3.4 days. Fix this by carrying on errors from previous checks and iterations as we traverse the table and ensuring we keep any error from previous checks. We keep iterating on the table even if an error is found so we can complain for all errors found in one shot. This works as -EINVAL is always returned on error anyway, and the check for error is any non-zero value. Fixes: 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks") Link: http://lkml.kernel.org/r/20170519033554.18592-2-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* fs/dcache.c: fix spin lockup issue on nlru->lockSahitya Tummala2017-10-121-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* CIFS: fix circular locking dependencyRabin Vincent2017-10-121-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 966681c9f029afd5decee069b7658bb58ad0a863 upstream. When a CIFS filesystem is mounted with the forcemand option and the following command is run on it, lockdep warns about a circular locking dependency between CifsInodeInfo::lock_sem and the inode lock. while echo foo > hello; do :; done & while touch -c hello; do :; done cifs_writev() takes the locks in the wrong order, but note that we can't only flip the order around because it releases the inode lock before the call to generic_write_sync() while it holds the lock_sem across that call. But, AFAICS, there is no need to hold the CifsInodeInfo::lock_sem across the generic_write_sync() call either, so we can release both the locks before generic_write_sync(), and change the order. ====================================================== WARNING: possible circular locking dependency detected 4.12.0-rc7+ #9 Not tainted ------------------------------------------------------ touch/487 is trying to acquire lock: (&cifsi->lock_sem){++++..}, at: cifsFileInfo_put+0x88f/0x16a0 but task is already holding lock: (&sb->s_type->i_mutex_key#11){+.+.+.}, at: utimes_common+0x3ad/0x870 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#11){+.+.+.}: __lock_acquire+0x1f74/0x38f0 lock_acquire+0x1cc/0x600 down_write+0x74/0x110 cifs_strict_writev+0x3cb/0x8c0 __vfs_write+0x4c1/0x930 vfs_write+0x14c/0x2d0 SyS_write+0xf7/0x240 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #0 (&cifsi->lock_sem){++++..}: check_prevs_add+0xfa0/0x1d10 __lock_acquire+0x1f74/0x38f0 lock_acquire+0x1cc/0x600 down_write+0x74/0x110 cifsFileInfo_put+0x88f/0x16a0 cifs_setattr+0x992/0x1680 notify_change+0x61a/0xa80 utimes_common+0x3d4/0x870 do_utimes+0x1c1/0x220 SyS_utimensat+0x84/0x1a0 entry_SYSCALL_64_fastpath+0x1f/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#11); lock(&cifsi->lock_sem); lock(&sb->s_type->i_mutex_key#11); lock(&cifsi->lock_sem); *** DEADLOCK *** 2 locks held by touch/487: #0: (sb_writers#10){.+.+.+}, at: mnt_want_write+0x41/0xb0 #1: (&sb->s_type->i_mutex_key#11){+.+.+.}, at: utimes_common+0x3ad/0x870 stack backtrace: CPU: 0 PID: 487 Comm: touch Not tainted 4.12.0-rc7+ #9 Call Trace: dump_stack+0xdb/0x185 print_circular_bug+0x45b/0x790 __lock_acquire+0x1f74/0x38f0 lock_acquire+0x1cc/0x600 down_write+0x74/0x110 cifsFileInfo_put+0x88f/0x16a0 cifs_setattr+0x992/0x1680 notify_change+0x61a/0xa80 utimes_common+0x3d4/0x870 do_utimes+0x1c1/0x220 SyS_utimensat+0x84/0x1a0 entry_SYSCALL_64_fastpath+0x1f/0xbe Fixes: 19dfc1f5f2ef03a52 ("cifs: fix the race in cifs_writev()") Signed-off-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Steve French <smfrench@gmail.com> Acked-by: Pavel Shilovsky <pshilov@microsoft.com> [bwh: Backported to 3.16: - Keep using mutex_{,un}lock() - Update both branches of if (!cifs_find_lock_conflict(...))] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* btrfs: Don't clear SGID when inheriting ACLsJan Kara2017-10-121-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | commit b7f8a09f8097db776b8d160862540e4fc1f51296 upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving posix_acl_update_mode() out of __btrfs_set_acl() into btrfs_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: linux-btrfs@vger.kernel.org CC: David Sterba <dsterba@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* xfs: Don't clear SGID when inheriting ACLsJan Kara2017-10-123-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | commit 8ba358756aa08414fa9e65a1a41d28304ed6fd7f upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by calling __xfs_set_acl() instead of xfs_set_acl() when setting up inode in xfs_generic_create(). That prevents SGID bit clearing and mode is properly set by posix_acl_create() anyway. We also reorder arguments of __xfs_set_acl() to match the ordering of xfs_set_acl() to make things consistent. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: Darrick J. Wong <darrick.wong@oracle.com> CC: linux-xfs@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Btrfs: fix invalid extent maps due to hole punchingFilipe Manana2017-10-121-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 609805d809733d0c669f21f710bdac308cc63cba upstream. While punching a hole in a range that is not aligned with the sector size (currently the same as the page size) we can end up leaving an extent map in memory with a length that is smaller then the sector size or with a start offset that is not aligned to the sector size. Both cases are not expected and can lead to problems. This issue is easily detected after the patch from commit a7e3b975a0f9 ("Btrfs: fix reported number of inode blocks"), introduced in kernel 4.12-rc1, in a scenario like the following for example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -c "pwrite -S 0xaa -b 100K 0 100K" /mnt/foo $ xfs_io -c "fpunch 60K 90K" /mnt/foo $ xfs_io -c "pwrite -S 0xbb -b 100K 50K 100K" /mnt/foo $ xfs_io -c "pwrite -S 0xcc -b 50K 100K 50K" /mnt/foo $ umount /mnt After the unmount operation we can see several warnings emmitted due to underflows related to space reservation counters: [ 2837.443299] ------------[ cut here ]------------ [ 2837.447395] WARNING: CPU: 8 PID: 2474 at fs/btrfs/inode.c:9444 btrfs_destroy_inode+0xe8/0x27e [btrfs] [ 2837.452108] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button se rio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_gene ric raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.458389] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.459754] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.462379] Call Trace: [ 2837.462379] dump_stack+0x68/0x92 [ 2837.462379] __warn+0xc2/0xdd [ 2837.462379] warn_slowpath_null+0x1d/0x1f [ 2837.462379] btrfs_destroy_inode+0xe8/0x27e [btrfs] [ 2837.462379] destroy_inode+0x3d/0x55 [ 2837.462379] evict+0x177/0x17e [ 2837.462379] dispose_list+0x50/0x71 [ 2837.462379] evict_inodes+0x132/0x141 [ 2837.462379] generic_shutdown_super+0x3f/0xeb [ 2837.462379] kill_anon_super+0x12/0x1c [ 2837.462379] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.462379] deactivate_locked_super+0x30/0x68 [ 2837.462379] deactivate_super+0x36/0x39 [ 2837.462379] cleanup_mnt+0x58/0x76 [ 2837.462379] __cleanup_mnt+0x12/0x14 [ 2837.462379] task_work_run+0x77/0x9b [ 2837.462379] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.462379] syscall_return_slowpath+0x196/0x1b9 [ 2837.462379] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.462379] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.462379] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.462379] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.462379] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.462379] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.462379] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.462379] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.519355] ---[ end trace e79345fe24b30b8d ]--- [ 2837.596256] ------------[ cut here ]------------ [ 2837.597625] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5699 btrfs_free_block_groups+0x246/0x3eb [btrfs] [ 2837.603547] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.659372] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.663359] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.663359] Call Trace: [ 2837.663359] dump_stack+0x68/0x92 [ 2837.663359] __warn+0xc2/0xdd [ 2837.663359] warn_slowpath_null+0x1d/0x1f [ 2837.663359] btrfs_free_block_groups+0x246/0x3eb [btrfs] [ 2837.663359] close_ctree+0x1dd/0x2e1 [btrfs] [ 2837.663359] ? evict_inodes+0x132/0x141 [ 2837.663359] btrfs_put_super+0x15/0x17 [btrfs] [ 2837.663359] generic_shutdown_super+0x6a/0xeb [ 2837.663359] kill_anon_super+0x12/0x1c [ 2837.663359] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.663359] deactivate_locked_super+0x30/0x68 [ 2837.663359] deactivate_super+0x36/0x39 [ 2837.663359] cleanup_mnt+0x58/0x76 [ 2837.663359] __cleanup_mnt+0x12/0x14 [ 2837.663359] task_work_run+0x77/0x9b [ 2837.663359] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.663359] syscall_return_slowpath+0x196/0x1b9 [ 2837.663359] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.663359] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.663359] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.663359] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.663359] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.663359] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.663359] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.663359] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.739445] ---[ end trace e79345fe24b30b8e ]--- [ 2837.745595] ------------[ cut here ]------------ [ 2837.746412] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5700 btrfs_free_block_groups+0x261/0x3eb [btrfs] [ 2837.747955] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.755395] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.756769] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.758526] Call Trace: [ 2837.758925] dump_stack+0x68/0x92 [ 2837.759383] __warn+0xc2/0xdd [ 2837.759383] warn_slowpath_null+0x1d/0x1f [ 2837.759383] btrfs_free_block_groups+0x261/0x3eb [btrfs] [ 2837.759383] close_ctree+0x1dd/0x2e1 [btrfs] [ 2837.759383] ? evict_inodes+0x132/0x141 [ 2837.759383] btrfs_put_super+0x15/0x17 [btrfs] [ 2837.759383] generic_shutdown_super+0x6a/0xeb [ 2837.759383] kill_anon_super+0x12/0x1c [ 2837.759383] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.759383] deactivate_locked_super+0x30/0x68 [ 2837.759383] deactivate_super+0x36/0x39 [ 2837.759383] cleanup_mnt+0x58/0x76 [ 2837.759383] __cleanup_mnt+0x12/0x14 [ 2837.759383] task_work_run+0x77/0x9b [ 2837.759383] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.759383] syscall_return_slowpath+0x196/0x1b9 [ 2837.759383] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.759383] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.759383] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.759383] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.759383] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.759383] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.759383] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.759383] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.777063] ---[ end trace e79345fe24b30b8f ]--- [ 2837.778235] ------------[ cut here ]------------ [ 2837.778856] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:9825 btrfs_free_block_groups+0x348/0x3eb [btrfs] [ 2837.791385] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.797711] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.798594] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.800118] Call Trace: [ 2837.800515] dump_stack+0x68/0x92 [ 2837.801015] __warn+0xc2/0xdd [ 2837.801471] warn_slowpath_null+0x1d/0x1f [ 2837.801698] btrfs_free_block_groups+0x348/0x3eb [btrfs] [ 2837.801698] close_ctree+0x1dd/0x2e1 [btrfs] [ 2837.801698] ? evict_inodes+0x132/0x141 [ 2837.801698] btrfs_put_super+0x15/0x17 [btrfs] [ 2837.801698] generic_shutdown_super+0x6a/0xeb [ 2837.801698] kill_anon_super+0x12/0x1c [ 2837.801698] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.801698] deactivate_locked_super+0x30/0x68 [ 2837.801698] deactivate_super+0x36/0x39 [ 2837.801698] cleanup_mnt+0x58/0x76 [ 2837.801698] __cleanup_mnt+0x12/0x14 [ 2837.801698] task_work_run+0x77/0x9b [ 2837.801698] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.801698] syscall_return_slowpath+0x196/0x1b9 [ 2837.801698] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.801698] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.801698] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.801698] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.801698] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.801698] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.801698] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.801698] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.818441] ---[ end trace e79345fe24b30b90 ]--- [ 2837.818991] BTRFS info (device sdc): space_info 1 has 7974912 free, is not full [ 2837.819830] BTRFS info (device sdc): space_info total=8388608, used=417792, pinned=0, reserved=0, may_use=18446744073709547520, readonly=0 What happens in the above example is the following: 1) When punching the hole, at btrfs_punch_hole(), the variable tail_len is set to 2048 (as tail_start is 148Kb + 1 and offset + len is 150Kb). This results in the creation of an extent map with a length of 2Kb starting at file offset 148Kb, through find_first_non_hole() -> btrfs_get_extent(). 2) The second write (first write after the hole punch operation), sets the range [50Kb, 152Kb[ to delalloc. 3) The third write, at btrfs_find_new_delalloc_bytes(), sees the extent map covering the range [148Kb, 150Kb[ and ends up calling set_extent_bit() for the same range, which results in splitting an existing extent state record, covering the range [148Kb, 152Kb[ into two 2Kb extent state records, covering the ranges [148Kb, 150Kb[ and [150Kb, 152Kb[. 4) Finally at lock_and_cleanup_extent_if_need(), immediately after calling btrfs_find_new_delalloc_bytes() we clear the delalloc bit from the range [100Kb, 152Kb[ which results in the btrfs_clear_bit_hook() callback being invoked against the two 2Kb extent state records that cover the ranges [148Kb, 150Kb[ and [150Kb, 152Kb[. When called against the first 2Kb extent state, it calls btrfs_delalloc_release_metadata() with a length argument of 2048 bytes. That function rounds up the length to a sector size aligned length, so it ends up considering a length of 4096 bytes, and then calls calc_csum_metadata_size() which results in decrementing the inode's csum_bytes counter by 4096 bytes, so after it stays a value of 0 bytes. Then the same happens when btrfs_clear_bit_hook() is called against the second extent state that has a length of 2Kb, covering the range [150Kb, 152Kb[, the length is rounded up to 4096 and calc_csum_metadata_size() ends up being called to decrement 4096 bytes from the inode's csum_bytes counter, which at that time has a value of 0, leading to an underflow, which is exactly what triggers the first warning, at btrfs_destroy_inode(). All the other warnings relate to several space accounting counters that underflow as well due to similar reasons. A similar case but where the hole punching operation creates an extent map with a start offset not aligned to the sector size is the following: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "fpunch 695K 820K" $SCRATCH_MNT/bar $ xfs_io -c "pwrite -S 0xaa 1008K 307K" $SCRATCH_MNT/bar $ xfs_io -c "pwrite -S 0xbb -b 630K 1073K 630K" $SCRATCH_MNT/bar $ xfs_io -c "pwrite -S 0xcc -b 459K 1068K 459K" $SCRATCH_MNT/bar $ umount /mnt During the unmount operation we get similar traces for the same reasons as in the first example. So fix the hole punching operation to make sure it never creates extent maps with a length that is not aligned to the sector size nor with a start offset that is not aligned to the sector size, as this breaks all assumptions and it's a land mine. Fixes: d77815461f04 ("btrfs: Avoid trucating page or punching hole in a already existed hole.") Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> [bwh: Backported to 3.16: - sectorsize is a member of btrfs_root not btrfs_fs_info - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Btrfs: skip commit transaction if we don't have enough pinned bytesLiu Bo2017-10-121-1/+1
| | | | | | | | | | | | | | | | | | | | commit 28785f70ef882e4798cd5706066a55dbf7adf80e upstream. We commit transaction in order to reclaim space from pinned bytes because it could process delayed refs, and in may_commit_transaction(), we check first if pinned bytes are enough for the required space, we then check if that plus bytes reserved for delayed insert are enough for the required space. This changes the code to the above logic. Fixes: b150a4f10d87 ("Btrfs: use a percpu to keep track of possibly pinned bytes") Tested-by: Nikolay Borisov <nborisov@suse.com> Reported-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* udf: Fix deadlock between writeback and udf_setsize()Jan Kara2017-10-121-2/+2
| | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* udf: Fix races with i_size changes during readpageJan Kara2017-10-121-2/+7
| | | | | | | | | | | | | | | | commit 9795e0e8ac0d6a3ee092f1b555b284b57feef99e upstream. __udf_adinicb_readpage() uses i_size several times. When truncate changes i_size while the function is running, it can observe several different values and thus e.g. expose uninitialized parts of page to userspace. Also use i_size_read() in the function since it does not hold inode_lock. Since i_size is guaranteed to be small, this cannot really cause any issues even on 32-bit archs but let's be careful. Fixes: 9c2fc0de1a6e638fe58c354a463f544f42a90a09 Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* f2fs: try to freeze in gc and discard threadsJaegeuk Kim2017-10-121-4/+5
| | | | | | | | | | commit 1d7be2708277edfef95171d52fb65ee26eaa076b upstream. This allows to freeze gc and discard threads. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> [bwh: Backported to 3.16: drop changes to discard thread] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* f2fs: load inode's flag from diskJaegeuk Kim2017-10-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 93607124c5450148e592c3d18ac533b4e5f25b8b upstream. This patch fixes missing inode flag loaded from disk, reported by Tom. [tom@localhost ~]$ sudo mount /dev/loop0 /mnt/ [tom@localhost ~]$ sudo chown tom:tom /mnt/ [tom@localhost ~]$ touch /mnt/testfile [tom@localhost ~]$ sudo chattr +i /mnt/testfile [tom@localhost ~]$ echo test > /mnt/testfile bash: /mnt/testfile: Operation not permitted [tom@localhost ~]$ rm /mnt/testfile rm: cannot remove '/mnt/testfile': Operation not permitted [tom@localhost ~]$ sudo umount /mnt/ [tom@localhost ~]$ sudo mount /dev/loop0 /mnt/ [tom@localhost ~]$ lsattr /mnt/testfile ----i-------------- /mnt/testfile [tom@localhost ~]$ echo test > /mnt/testfile [tom@localhost ~]$ rm /mnt/testfile [tom@localhost ~]$ sudo umount /mnt/ Reported-by: Tom Yan <tom.ty89@outlook.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> [bwh: Backported to 3.16: mark_inode_dirty() is in the right place, so only f2fs_iget() needs to be changed] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ptrace: use fsuid, fsgid, effective creds for fs access checksJann Horn2017-09-155-16/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit caaee6234d05a58c5b4d05e7bf766131b810a657 upstream. By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.16: - Update mm_access() calls in fs/proc/task_{,no}mmu.c too - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAILNeilBrown2017-09-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* CIFS: Improve readdir verbosityPavel Shilovsky2017-09-152-4/+9
| | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* configfs: Fix race between create_link and configfs_rmdirNicholas Bellinger2017-09-151-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Ben Hutchings <ben@decadent.org.uk>
* excessive checks in ufs_write_failed() and ufs_evict_inode()Al Viro2017-09-152-7/+4
| | | | | | | | | | | | | | | | commit babef37dccbaa49249a22bae9150686815d7be71 upstream. As it is, short copy in write() to append-only file will fail to truncate the excessive allocated blocks. As the matter of fact, all checks in ufs_truncate_blocks() are either redundant or wrong for that caller. As for the only other caller (ufs_evict_inode()), we only need the file type checks there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: - No functions need to be renamed - Adjust filenames, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ufs: set correct ->s_maxsizeAl Viro2017-09-151-0/+18
| | | | | | | commit 6b0d144fa758869bdd652c50aa41aaf601232550 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ufs: restore maintaining ->i_blocksAl Viro2017-09-152-1/+26
| | | | | | | | commit eb315d2ae614493fd1ebb026c75a80573d84f7ad upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: open-code i_blocksize()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* fix ufs_isblockset()Al Viro2017-09-151-3/+7
| | | | | | | commit 414cf7186dbec29bd946c138d6b5c09da5955a08 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* fs/ufs: Set UFS default maximum bytes per fileRichard Narron2017-09-151-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 239e250e4acbc0104d514307029c0839e834a51a upstream. This fixes a problem with reading files larger than 2GB from a UFS-2 file system: https://bugzilla.kernel.org/show_bug.cgi?id=195721 The incorrect UFS s_maxsize limit became a problem as of commit c2a9737f45e2 ("vfs,mm: fix a dead loop in truncate_inode_pages_range()") which started using s_maxbytes to avoid a page index overflow in do_generic_file_read(). That caused files to be truncated on UFS-2 file systems because the default maximum file size is 2GB (MAX_NON_LFS) and UFS didn't update it. Here I simply increase the default to a common value used by other file systems. Signed-off-by: Richard Narron <comet.berkeley@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will B <will.brokenbourgh2877@gmail.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* btrfs: fix memory leak in update_space_info failure pathJeff Mahoney2017-09-151-0/+1
| | | | | | | | | | | | | commit 896533a7da929136d0432713f02a3edffece2826 upstream. If we fail to add the space_info kobject, we'll leak the memory for the percpu counter. Fixes: 6ab0a2029c (btrfs: publish allocation data in sysfs) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* btrfs: use correct types for page indices in btrfs_page_exists_in_rangeDavid Sterba2017-09-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit cc2b702c52094b637a351d7491ac5200331d0445 upstream. Variables start_idx and end_idx are supposed to hold a page index derived from the file offsets. The int type is not the right one though, offsets larger than 1 << 44 will get silently trimmed off the high bits. (1 << 44 is 16TiB) What can go wrong, if start is below the boundary and end gets trimmed: - if there's a page after start, we'll find it (radix_tree_gang_lookup_slot) - the final check "if (page->index <= end_idx)" will unexpectedly fail The function will return false, ie. "there's no page in the range", although there is at least one. btrfs_page_exists_in_range is used to prevent races in: * in hole punching, where we make sure there are not pages in the truncated range, otherwise we'll wait for them to finish and redo truncation, but we're going to replace the pages with holes anyway so the only problem is the intermediate state * lock_extent_direct: we want to make sure there are no pages before we lock and start DIO, to prevent stale data reads For practical occurence of the bug, there are several constaints. The file must be quite large, the affected range must cross the 16TiB boundary and the internal state of the file pages and pending operations must match. Also, we must not have started any ordered data in the range, otherwise we don't even reach the buggy function check. DIO locking tries hard in several places to avoid deadlocks with buffered IO and avoids waiting for ranges. The worst consequence seems to be stale data read. CC: Liu Bo <bo.li.liu@oracle.com> Fixes: fc4adbff823f7 ("btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking") Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ext4: fix fdatasync(2) after extent manipulation operationsJan Kara2017-09-152-0/+5
| | | | | | | | | | | | | | | | | | | | commit 67a7d5f561f469ad2fa5154d2888258ab8e6df7c upstream. Currently, extent manipulation operations such as hole punch, range zeroing, or extent shifting do not record the fact that file data has changed and thus fdatasync(2) has a work to do. As a result if we crash e.g. after a punch hole and fdatasync, user can still possibly see the punched out data after journal replay. Test generic/392 fails due to these problems. Fix the problem by properly marking that file data has changed in these operations. Fixes: a4bb6b64e39abc0e41ca077725f2a72c868e7622 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> [bwh: Backported to 3.16: drop change in ext4_insert_range()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* ext4: fix data corruption for mmap writesJan Kara2017-09-151-2/+16
| | | | | | | | | | | | | | | | | | | commit a056bdaae7a181f7dcc876cfab2f94538e508709 upstream. mpage_submit_page() can race with another process growing i_size and writing data via mmap to the written-back page. As mpage_submit_page() samples i_size too early, it may happen that ext4_bio_write_page() zeroes out too large tail of the page and thus corrupts user data. Fix the problem by sampling i_size only after the page has been write-protected in page tables by clear_page_dirty_for_io() call. Reported-by: Michael Zimmer <michael@swarm64.com> Fixes: cb20d5188366f04d96d2e07b1240cc92170ade40 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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