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| author | Theodore Ts'o <tytso@mit.edu> | 2016-07-05 20:01:52 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-16 09:35:00 +0200 |
| commit | 9cfaab733a0143f19de96c97c1876d56800478a4 (patch) | |
| tree | 642028b15675083b92506038f6aba6ef87509612 /net/switchdev/switchdev.c | |
| parent | efc588bf340f52863f9faa30970928e829c1043a (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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/switchdev/switchdev.c')
0 files changed, 0 insertions, 0 deletions