diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2018-06-14 12:55:10 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-11 16:29:17 +0200 |
| commit | d69a9df614fc68741efcb0fcc020f05caa99d668 (patch) | |
| tree | ffd3ad6f40525b4267ac6c0928ae171a3be90bd5 /fs/ext4/extents.c | |
| parent | 44a4bc970bfae625d0ec9ecdfefc88c9d93dfe6c (diff) | |
ext4: verify the depth of extent tree in ext4_find_extent()
commit bc890a60247171294acc0bd67d211fa4b88d40ba upstream.
If there is a corupted file system where the claimed depth of the
extent tree is -1, this can cause a massive buffer overrun leading to
sadness.
This addresses CVE-2018-10877.
https://bugzilla.kernel.org/show_bug.cgi?id=199417
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 883e89a903d1..5592b7726241 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -881,6 +881,12 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block, eh = ext_inode_hdr(inode); depth = ext_depth(inode); + if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) { + EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d", + depth); + ret = -EFSCORRUPTED; + goto err; + } if (path) { ext4_ext_drop_refs(path); |