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| author | Theodore Ts'o <tytso@mit.edu> | 2016-07-05 20:01:52 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-11-20 01:16:46 +0000 |
| commit | 24b38673b286a615a86836f9c19423a43a404982 (patch) | |
| tree | 1dff294e0838c2ea81d575b7bae864664b402b49 /include/linux/timerqueue.h | |
| parent | 0180a0216dc2e7807c7ddcb9d71af363f70796a0 (diff) | |
ext4: validate s_reserved_gdt_blocks on mount
commit 5b9554dc5bf008ae7f68a52e3d7e76c0920938a2 upstream.
If s_reserved_gdt_blocks is extremely large, it's possible for
ext4_init_block_bitmap(), which is called when ext4 sets up an
uninitialized block bitmap, to corrupt random kernel memory. Add the
same checks which e2fsck has --- it must never be larger than
blocksize / sizeof(__u32) --- and then add a backup check in
ext4_init_block_bitmap() in case the superblock gets modified after
the file system is mounted.
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.16:
- Use EIO instead of EFSCORRUPTED
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'include/linux/timerqueue.h')
0 files changed, 0 insertions, 0 deletions