Commit 672ca9dd authored by Nicolas Pitre's avatar Nicolas Pitre

Cramfs: fix abad comparison when wrap-arounds occur

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: default avatarAnatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
parent 84df9525
......@@ -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;
}
......
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