f2fs: fix to do sanity check on last xattr entry in __f2fs_setxattr()
commit
5598b24efaf4892741c798b425d543e4bed357a1 upstream.
As Wenqing Liu reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=215235
- Overview
page fault in f2fs_setxattr() when mount and operate on corrupted image
- Reproduce
tested on kernel 5.16-rc3, 5.15.X under root
1. unzip tmp7.zip
2. ./single.sh f2fs 7
Sometimes need to run the script several times
- Kernel dump
loop0: detected capacity change from 0 to 131072
F2FS-fs (loop0): Found nat_bits in checkpoint
F2FS-fs (loop0): Mounted with checkpoint version =
7548c2ee
BUG: unable to handle page fault for address:
ffffe47bc7123f48
RIP: 0010:kfree+0x66/0x320
Call Trace:
__f2fs_setxattr+0x2aa/0xc00 [f2fs]
f2fs_setxattr+0xfa/0x480 [f2fs]
__f2fs_set_acl+0x19b/0x330 [f2fs]
__vfs_removexattr+0x52/0x70
__vfs_removexattr_locked+0xb1/0x140
vfs_removexattr+0x56/0x100
removexattr+0x57/0x80
path_removexattr+0xa3/0xc0
__x64_sys_removexattr+0x17/0x20
do_syscall_64+0x37/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
The root cause is in __f2fs_setxattr(), we missed to do sanity check on
last xattr entry, result in out-of-bound memory access during updating
inconsistent xattr data of target inode.
After the fix, it can detect such xattr inconsistency as below:
F2FS-fs (loop11): inode (7) has invalid last xattr entry, entry_size: 60676
F2FS-fs (loop11): inode (8) has corrupted xattr
F2FS-fs (loop11): inode (8) has corrupted xattr
F2FS-fs (loop11): inode (8) has invalid last xattr entry, entry_size: 47736
Cc: stable@vger.kernel.org
Reported-by: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>