| From 2f25d72c9a5e1ba2befd9a74f796d89285c1cbc3 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sun, 11 Aug 2019 15:52:27 -0700 |
| Subject: xfs: don't crash on null attr fork xfs_bmapi_read |
| |
| From: Darrick J. Wong <darrick.wong@oracle.com> |
| |
| [ Upstream commit 8612de3f7ba6e900465e340516b8313806d27b2d ] |
| |
| Zorro Lang reported a crash in generic/475 if we try to inactivate a |
| corrupt inode with a NULL attr fork (stack trace shortened somewhat): |
| |
| RIP: 0010:xfs_bmapi_read+0x311/0xb00 [xfs] |
| RSP: 0018:ffff888047f9ed68 EFLAGS: 00010202 |
| RAX: dffffc0000000000 RBX: ffff888047f9f038 RCX: 1ffffffff5f99f51 |
| RDX: 0000000000000002 RSI: 0000000000000008 RDI: 0000000000000012 |
| RBP: ffff888002a41f00 R08: ffffed10005483f0 R09: ffffed10005483ef |
| R10: ffffed10005483ef R11: ffff888002a41f7f R12: 0000000000000004 |
| R13: ffffe8fff53b5768 R14: 0000000000000005 R15: 0000000000000001 |
| FS: 00007f11d44b5b80(0000) GS:ffff888114200000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 0000000000ef6000 CR3: 000000002e176003 CR4: 00000000001606e0 |
| Call Trace: |
| xfs_dabuf_map.constprop.18+0x696/0xe50 [xfs] |
| xfs_da_read_buf+0xf5/0x2c0 [xfs] |
| xfs_da3_node_read+0x1d/0x230 [xfs] |
| xfs_attr_inactive+0x3cc/0x5e0 [xfs] |
| xfs_inactive+0x4c8/0x5b0 [xfs] |
| xfs_fs_destroy_inode+0x31b/0x8e0 [xfs] |
| destroy_inode+0xbc/0x190 |
| xfs_bulkstat_one_int+0xa8c/0x1200 [xfs] |
| xfs_bulkstat_one+0x16/0x20 [xfs] |
| xfs_bulkstat+0x6fa/0xf20 [xfs] |
| xfs_ioc_bulkstat+0x182/0x2b0 [xfs] |
| xfs_file_ioctl+0xee0/0x12a0 [xfs] |
| do_vfs_ioctl+0x193/0x1000 |
| ksys_ioctl+0x60/0x90 |
| __x64_sys_ioctl+0x6f/0xb0 |
| do_syscall_64+0x9f/0x4d0 |
| entry_SYSCALL_64_after_hwframe+0x49/0xbe |
| RIP: 0033:0x7f11d39a3e5b |
| |
| The "obvious" cause is that the attr ifork is null despite the inode |
| claiming an attr fork having at least one extent, but it's not so |
| obvious why we ended up with an inode in that state. |
| |
| Reported-by: Zorro Lang <zlang@redhat.com> |
| Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204031 |
| Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> |
| Reviewed-by: Bill O'Donnell <billodo@redhat.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| fs/xfs/libxfs/xfs_bmap.c | 29 +++++++++++++++++++++-------- |
| 1 file changed, 21 insertions(+), 8 deletions(-) |
| |
| diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c |
| index 06a7da8dbda5c..38dc0b43c3665 100644 |
| --- a/fs/xfs/libxfs/xfs_bmap.c |
| +++ b/fs/xfs/libxfs/xfs_bmap.c |
| @@ -3841,15 +3841,28 @@ xfs_bmapi_read( |
| XFS_STATS_INC(mp, xs_blk_mapr); |
| |
| ifp = XFS_IFORK_PTR(ip, whichfork); |
| + if (!ifp) { |
| + /* No CoW fork? Return a hole. */ |
| + if (whichfork == XFS_COW_FORK) { |
| + mval->br_startoff = bno; |
| + mval->br_startblock = HOLESTARTBLOCK; |
| + mval->br_blockcount = len; |
| + mval->br_state = XFS_EXT_NORM; |
| + *nmap = 1; |
| + return 0; |
| + } |
| |
| - /* No CoW fork? Return a hole. */ |
| - if (whichfork == XFS_COW_FORK && !ifp) { |
| - mval->br_startoff = bno; |
| - mval->br_startblock = HOLESTARTBLOCK; |
| - mval->br_blockcount = len; |
| - mval->br_state = XFS_EXT_NORM; |
| - *nmap = 1; |
| - return 0; |
| + /* |
| + * A missing attr ifork implies that the inode says we're in |
| + * extents or btree format but failed to pass the inode fork |
| + * verifier while trying to load it. Treat that as a file |
| + * corruption too. |
| + */ |
| +#ifdef DEBUG |
| + xfs_alert(mp, "%s: inode %llu missing fork %d", |
| + __func__, ip->i_ino, whichfork); |
| +#endif /* DEBUG */ |
| + return -EFSCORRUPTED; |
| } |
| |
| if (!(ifp->if_flags & XFS_IFEXTENTS)) { |
| -- |
| 2.20.1 |
| |