diff options
| author | Jan Kara <jack@suse.cz> | 2012-07-10 17:58:04 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-08-02 14:37:46 +0100 |
| commit | c17fcfb52422d098dde1ccdc4a3d24a7ceeb33e2 (patch) | |
| tree | ec7c3b691db41e14d34a6af42c3349fc5e221a03 | |
| parent | e44be732863c136e9560c6bf7bf9b9d709a59fca (diff) | |
udf: Improve table length check to avoid possible overflow
commit 57b9655d01ef057a523e810d29c37ac09b80eead upstream.
When a partition table length is corrupted to be close to 1 << 32, the
check for its length may overflow on 32-bit systems and we will think
the length is valid. Later on the kernel can crash trying to read beyond
end of buffer. Fix the check to avoid possible overflow.
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | fs/udf/super.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/udf/super.c b/fs/udf/super.c index 270e1356fd01..516b7f00ab78 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1285,7 +1285,7 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, BUG_ON(ident != TAG_IDENT_LVD); lvd = (struct logicalVolDesc *)bh->b_data; table_len = le32_to_cpu(lvd->mapTableLength); - if (sizeof(*lvd) + table_len > sb->s_blocksize) { + if (table_len > sb->s_blocksize - sizeof(*lvd)) { udf_err(sb, "error loading logical volume descriptor: " "Partition table too long (%u > %lu)\n", table_len, sb->s_blocksize - sizeof(*lvd)); |