From 7d71a671a2d900606d3a62ed5976d3b0feada3a6 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 5 Jun 2018 10:06:44 -0700 Subject: [PATCH] xfs: verify extent size hint is valid in inode verifier There are rules for vald extent size hints. We enforce them when applications set them, but fuzzers violate those rules and that screws us over. This results in alignment assertion failures when setting up allocations such as this in direct IO: XFS: Assertion failed: ap->length, file: fs/xfs/libxfs/xfs_bmap.c, line: 3432 .... Call Trace: xfs_bmap_btalloc+0x415/0x910 xfs_bmapi_write+0x71c/0x12e0 xfs_iomap_write_direct+0x2a9/0x420 xfs_file_iomap_begin+0x4dc/0xa70 iomap_apply+0x43/0x100 iomap_file_buffered_write+0x62/0x90 xfs_file_buffered_aio_write+0xba/0x300 __vfs_write+0xd5/0x150 vfs_write+0xb6/0x180 ksys_write+0x45/0xa0 do_syscall_64+0x5a/0x180 entry_SYSCALL_64_after_hwframe+0x49/0xbe And from xfs_db: core.extsize = 10380288 Which is not an integer multiple of the block size, and so violates Rule #7 for setting extent size hints. Validate extent size hint rules in the inode verifier to catch this. Signed-off-by: Dave Chinner Reviewed-by: Carlos Maiolino Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_inode_buf.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index 1201107eabc6..1fe18555b451 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -397,6 +397,7 @@ xfs_dinode_verify( xfs_ino_t ino, struct xfs_dinode *dip) { + xfs_failaddr_t fa; uint16_t mode; uint16_t flags; uint64_t flags2; @@ -513,6 +514,12 @@ xfs_dinode_verify( return __this_address; } + /* extent size hint validation */ + fa = xfs_inode_validate_extsize(mp, be32_to_cpu(dip->di_extsize), + mode, flags); + if (fa) + return fa; + /* only version 3 or greater inodes are extensively verified here */ if (dip->di_version < 3) return NULL; @@ -521,7 +528,7 @@ xfs_dinode_verify( /* don't allow reflink/cowextsize if we don't have reflink */ if ((flags2 & (XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE)) && - !xfs_sb_version_hasreflink(&mp->m_sb)) + !xfs_sb_version_hasreflink(&mp->m_sb)) return __this_address; /* only regular files get reflink */