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| author | Amir Goldstein <amir73il@gmail.com> | 2017-01-17 11:41:41 -0800 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2017-01-17 11:41:41 -0800 |
| commit | 3c6f46eacd876bd723a9bad3c6882714c052fd8e (patch) | |
| tree | 4ea7023de1e62d8df75e5af72c0485d5ef61c175 /fs | |
| parent | bf46ecc3d8cca05f2907cf482755c42c2b11a79d (diff) | |
| download | linux-3c6f46eacd876bd723a9bad3c6882714c052fd8e.tar.gz linux-3c6f46eacd876bd723a9bad3c6882714c052fd8e.tar.xz | |
xfs: sanity check directory inode di_size
This changes fixes an assertion hit when fuzzing on-disk
i_mode values.
The easy case to fix is when changing an empty file
i_mode to S_IFDIR. In this case, xfs_dinode_verify()
detects an illegal zero size for directory and fails
to load the inode structure from disk.
For the case of non empty file whose i_mode is changed
to S_IFDIR, the ASSERT() statement in xfs_dir2_isblock()
is replaced with return -EFSCORRUPTED, to avoid interacting
with corrupted jusk also when XFS_DEBUG is disabled.
Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/xfs/libxfs/xfs_dir2.c | 3 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_inode_buf.c | 7 |
2 files changed, 7 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c index c58d72c220f5..4f7913f84b28 100644 --- a/fs/xfs/libxfs/xfs_dir2.c +++ b/fs/xfs/libxfs/xfs_dir2.c @@ -631,7 +631,8 @@ xfs_dir2_isblock( if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK))) return rval; rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize; - ASSERT(rval == 0 || args->dp->i_d.di_size == args->geo->blksize); + if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize) + return -EFSCORRUPTED; *vp = rval; return 0; } diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index dd483e2767f7..0091ac3f5241 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -386,6 +386,7 @@ xfs_dinode_verify( xfs_ino_t ino, struct xfs_dinode *dip) { + uint16_t mode; uint16_t flags; uint64_t flags2; @@ -396,8 +397,10 @@ xfs_dinode_verify( if (be64_to_cpu(dip->di_size) & (1ULL << 63)) return false; - /* No zero-length symlinks. */ - if (S_ISLNK(be16_to_cpu(dip->di_mode)) && dip->di_size == 0) + mode = be16_to_cpu(dip->di_mode); + + /* No zero-length symlinks/dirs. */ + if ((S_ISLNK(mode) || S_ISDIR(mode)) && dip->di_size == 0) return false; /* only version 3 or greater inodes are extensively verified here */ |