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| author | Theodore Ts'o <tytso@mit.edu> | 2016-07-06 02:01:52 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2016-07-06 02:01:52 +0200 |
| commit | 5b9554dc5bf008ae7f68a52e3d7e76c0920938a2 (patch) | |
| tree | 0e77ba0fce0b9b68920ae7f7d1561ffcb690ba04 /fs/ext2/balloc.c | |
| parent | ext4: remove unused page_idx (diff) | |
| download | linux-5b9554dc5bf008ae7f68a52e3d7e76c0920938a2.tar.xz linux-5b9554dc5bf008ae7f68a52e3d7e76c0920938a2.zip | |
ext4: validate s_reserved_gdt_blocks on mount
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>
Cc: stable@vger.kernel.org
Diffstat (limited to 'fs/ext2/balloc.c')
0 files changed, 0 insertions, 0 deletions