omfs: fix oops when file metadata is corrupted
A fuzzed fileystem image failed with OMFS when the extent count was
used in a loop without being checked against the max number of extents.
It also provoked a signed division for an array index that was checked
as if unsigned, leading to index by -1.
omfsck will be updated to fix these cases, in the meantime bail out
gracefully.
Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/omfs/bitmap.c b/fs/omfs/bitmap.c
index 697663b..e1c0ec0 100644
--- a/fs/omfs/bitmap.c
+++ b/fs/omfs/bitmap.c
@@ -92,7 +92,7 @@
struct buffer_head *bh;
struct omfs_sb_info *sbi = OMFS_SB(sb);
int bits_per_entry = 8 * sb->s_blocksize;
- int map, bit;
+ unsigned int map, bit;
int ret = 0;
u64 tmp;
@@ -176,7 +176,8 @@
struct omfs_sb_info *sbi = OMFS_SB(sb);
int bits_per_entry = 8 * sb->s_blocksize;
u64 tmp;
- int map, bit, ret;
+ unsigned int map, bit;
+ int ret;
tmp = block;
bit = do_div(tmp, bits_per_entry);