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* [PATCH] loop: fix setting arbitrarily large block size
@ 2021-06-22 16:10 Shreyansh Chouhan
  2021-06-23  5:09 ` [RESEND PATCH] " Shreyansh Chouhan
  0 siblings, 1 reply; 6+ messages in thread
From: Shreyansh Chouhan @ 2021-06-22 16:10 UTC (permalink / raw)
  To: axboe
  Cc: Shreyansh Chouhan, linux-block, linux-kernel,
	syzbot+cf89d662483d6a1a0790

loop_validate_block_size took an unsigned short argument. Passing an
argument with size greater than the size of unsigned short would cause
an overflow and could potentially render the upper bound check on the
block size useless, allowing to set an arbitrarily large block size.

Reproted-by: syzbot+cf89d662483d6a1a0790@syzkaller.appspotmail.com
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>
---
 drivers/block/loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 9a758cf66507..635baff0dd66 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -236,7 +236,7 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
  * @bsize: size to validate
  */
 static int
-loop_validate_block_size(unsigned short bsize)
+loop_validate_block_size(unsigned long bsize)
 {
 	if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize))
 		return -EINVAL;
-- 
2.31.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-07-20  7:26 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-22 16:10 [PATCH] loop: fix setting arbitrarily large block size Shreyansh Chouhan
2021-06-23  5:09 ` [RESEND PATCH] " Shreyansh Chouhan
2021-06-24  6:14   ` Christoph Hellwig
2021-06-26  8:24   ` [PATCH v2] " Shreyansh Chouhan
2021-06-28  5:34     ` Christoph Hellwig
2021-07-20  7:25     ` Shreyansh Chouhan

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