diff options
| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2018-10-30 13:26:15 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-13 11:12:52 -0800 |
| commit | 29b85eacc07ade392d2a50c4e728f09cf677e70a (patch) | |
| tree | bd2578448ba0ce5db758feacddffec8182b3a317 | |
| parent | cb3de273d7a34451dfc9d5042703fe3c6679b568 (diff) | |
Cramfs: fix abad comparison when wrap-arounds occur
commit 672ca9dd13f1aca0c17516f76fc5b0e8344b3e46 upstream.
It is possible for corrupted filesystem images to produce very large
block offsets that may wrap when a length is added, and wrongly pass
the buffer size test.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/cramfs/inode.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index f408994fc632..6e000392e4a4 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -202,7 +202,8 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, continue; blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT; blk_offset += offset; - if (blk_offset + len > BUFFER_SIZE) + if (blk_offset > BUFFER_SIZE || + blk_offset + len > BUFFER_SIZE) continue; return read_buffers[i] + blk_offset; } |