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>
This commit is contained in:
parent
9632c0339b
commit
9d9da6fe1f
@ -202,7 +202,8 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset,
|
|||||||
continue;
|
continue;
|
||||||
blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT;
|
blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT;
|
||||||
blk_offset += offset;
|
blk_offset += offset;
|
||||||
if (blk_offset + len > BUFFER_SIZE)
|
if (blk_offset > BUFFER_SIZE ||
|
||||||
|
blk_offset + len > BUFFER_SIZE)
|
||||||
continue;
|
continue;
|
||||||
return read_buffers[i] + blk_offset;
|
return read_buffers[i] + blk_offset;
|
||||||
}
|
}
|
||||||
|
Loading…
Reference in New Issue
Block a user