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* [PATCH] ext2fs: fix integer overflow in rb_get_bmap_range
@ 2014-12-09 19:30 Dmitry Monakhov
  2014-12-09 19:48 ` Dmitry Monakhov
  2014-12-11 22:58 ` Theodore Ts'o
  0 siblings, 2 replies; 3+ messages in thread
From: Dmitry Monakhov @ 2014-12-09 19:30 UTC (permalink / raw)
  To: linux-ext4; +Cc: Dmitry Monakhov

bmap_rb_extent is defined as __u64:blk __u64:count. So count can exceed INT_MAX on
populated filesystems

TESTCASE: xfstest ext4/004

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
 lib/ext2fs/blkmap64_rb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/ext2fs/blkmap64_rb.c b/lib/ext2fs/blkmap64_rb.c
index 8d1778d..e290ade 100644
--- a/lib/ext2fs/blkmap64_rb.c
+++ b/lib/ext2fs/blkmap64_rb.c
@@ -733,7 +733,7 @@ static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
 	struct rb_node *parent = NULL, *next, **n;
 	struct ext2fs_rb_private *bp;
 	struct bmap_rb_extent *ext;
-	int count;
+	__u64 count;
 	__u64 pos;
 
 	bp = (struct ext2fs_rb_private *) bitmap->private;
@@ -765,9 +765,9 @@ static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
 		if (pos >= start + num)
 			break;
 		if (pos < start) {
-			count -= start - pos;
-			if (count < 0)
+			if (pos + count <  start)
 				continue;
+			count -= start - pos;
 			pos = start;
 		}
 		if (pos + count > start + num)
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] ext2fs: fix integer overflow in rb_get_bmap_range
  2014-12-09 19:30 [PATCH] ext2fs: fix integer overflow in rb_get_bmap_range Dmitry Monakhov
@ 2014-12-09 19:48 ` Dmitry Monakhov
  2014-12-11 22:58 ` Theodore Ts'o
  1 sibling, 0 replies; 3+ messages in thread
From: Dmitry Monakhov @ 2014-12-09 19:48 UTC (permalink / raw)
  To: linux-ext4, Theodore Ts'o

Dmitry Monakhov <dmonakhov@openvz.org> writes:

This is the patch for the issue which I complain you about prev
Friday. It takes longer than I expect, but now all my resize tests
succeeded. In fact issue may be triggered in real life situation
if someone use ballooning technique (consume space via fallocate)
> bmap_rb_extent is defined as __u64:blk __u64:count. So count can exceed INT_MAX on
> populated filesystems
>
> TESTCASE: xfstest ext4/004
>
> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
> ---
>  lib/ext2fs/blkmap64_rb.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/lib/ext2fs/blkmap64_rb.c b/lib/ext2fs/blkmap64_rb.c
> index 8d1778d..e290ade 100644
> --- a/lib/ext2fs/blkmap64_rb.c
> +++ b/lib/ext2fs/blkmap64_rb.c
> @@ -733,7 +733,7 @@ static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
>  	struct rb_node *parent = NULL, *next, **n;
>  	struct ext2fs_rb_private *bp;
>  	struct bmap_rb_extent *ext;
> -	int count;
> +	__u64 count;
>  	__u64 pos;
>  
>  	bp = (struct ext2fs_rb_private *) bitmap->private;
> @@ -765,9 +765,9 @@ static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
>  		if (pos >= start + num)
>  			break;
>  		if (pos < start) {
> -			count -= start - pos;
> -			if (count < 0)
> +			if (pos + count <  start)
>  				continue;
> +			count -= start - pos;
>  			pos = start;
>  		}
>  		if (pos + count > start + num)
> -- 
> 1.8.3.1

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] ext2fs: fix integer overflow in rb_get_bmap_range
  2014-12-09 19:30 [PATCH] ext2fs: fix integer overflow in rb_get_bmap_range Dmitry Monakhov
  2014-12-09 19:48 ` Dmitry Monakhov
@ 2014-12-11 22:58 ` Theodore Ts'o
  1 sibling, 0 replies; 3+ messages in thread
From: Theodore Ts'o @ 2014-12-11 22:58 UTC (permalink / raw)
  To: Dmitry Monakhov; +Cc: linux-ext4

On Tue, Dec 09, 2014 at 11:30:16PM +0400, Dmitry Monakhov wrote:
> bmap_rb_extent is defined as __u64:blk __u64:count. So count can exceed INT_MAX on
> populated filesystems
> 
> TESTCASE: xfstest ext4/004
> 
> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>

Applied, thanks.

					- Ted

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2014-12-11 22:58 UTC | newest]

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2014-12-09 19:30 [PATCH] ext2fs: fix integer overflow in rb_get_bmap_range Dmitry Monakhov
2014-12-09 19:48 ` Dmitry Monakhov
2014-12-11 22:58 ` Theodore Ts'o

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