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* [PATCH] fs: btrfs: fix potential overflow
@ 2014-08-24  5:41 Brian Norris
  2014-08-24  9:44 ` Timofey Titovets
  2014-08-26  6:47 ` [PATCH v2] " Brian Norris
  0 siblings, 2 replies; 4+ messages in thread
From: Brian Norris @ 2014-08-24  5:41 UTC (permalink / raw)
  To: Chris Mason; +Cc: Josef Bacik, linux-btrfs, Linux Kernel, Brian Norris

It looks like this intended to be 64-bit arithmetic, but it's actually
performed as 32-bit. Fix that. (Note that 'increment' was being
initialized twice, so this patch removes one of those.)

Caught by Coverity Scan (CID 1201422).

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
Untested

 fs/btrfs/scrub.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index b6d198f5181e..b1a8127737b4 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2320,26 +2320,26 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	do_div(nstripes, map->stripe_len);
 	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
 		offset = map->stripe_len * num;
-		increment = map->stripe_len * map->num_stripes;
+		increment *= map->num_stripes;
 		mirror_num = 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
 		int factor = map->num_stripes / map->sub_stripes;
 		offset = map->stripe_len * (num / map->sub_stripes);
-		increment = map->stripe_len * factor;
+		increment *= factor;
 		mirror_num = num % map->sub_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
-		increment = map->stripe_len;
+		increment *= 1;
 		mirror_num = num % map->num_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-		increment = map->stripe_len;
+		increment *= 1;
 		mirror_num = num % map->num_stripes + 1;
 	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
 				BTRFS_BLOCK_GROUP_RAID6)) {
 		get_raid56_logic_offset(physical, num, map, &offset);
-		increment = map->stripe_len * nr_data_stripes(map);
+		increment *= nr_data_stripes(map);
 		mirror_num = 1;
 	} else {
-		increment = map->stripe_len;
+		increment *= 1;
 		mirror_num = 1;
 	}
 
-- 
1.7.9.5


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] fs: btrfs: fix potential overflow
  2014-08-24  5:41 [PATCH] fs: btrfs: fix potential overflow Brian Norris
@ 2014-08-24  9:44 ` Timofey Titovets
  2014-08-26  6:45   ` Brian Norris
  2014-08-26  6:47 ` [PATCH v2] " Brian Norris
  1 sibling, 1 reply; 4+ messages in thread
From: Timofey Titovets @ 2014-08-24  9:44 UTC (permalink / raw)
  To: Brian Norris; +Cc: Chris Mason, Josef Bacik, linux-btrfs, Linux Kernel

2014-08-24 8:41 GMT+03:00 Brian Norris <computeaboversforpeace@gmail.com>:
> It looks like this intended to be 64-bit arithmetic, but it's actually
> performed as 32-bit. Fix that. (Note that 'increment' was being
> initialized twice, so this patch removes one of those.)
>
> Caught by Coverity Scan (CID 1201422).
>
> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
> ---
> Untested
>
>  fs/btrfs/scrub.c |   12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index b6d198f5181e..b1a8127737b4 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -2320,26 +2320,26 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>         do_div(nstripes, map->stripe_len);
>         if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
>                 offset = map->stripe_len * num;
> -               increment = map->stripe_len * map->num_stripes;
> +               increment *= map->num_stripes;
>                 mirror_num = 1;
>         } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
>                 int factor = map->num_stripes / map->sub_stripes;
>                 offset = map->stripe_len * (num / map->sub_stripes);
> -               increment = map->stripe_len * factor;
> +               increment *= factor;
>                 mirror_num = num % map->sub_stripes + 1;
>         } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
> -               increment = map->stripe_len;
> +               increment *= 1;
Why? I think multiple by one is useless or i miss something?

>                 mirror_num = num % map->num_stripes + 1;
>         } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
> -               increment = map->stripe_len;
> +               increment *= 1;
Same as above.

>                 mirror_num = num % map->num_stripes + 1;
>         } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
>                                 BTRFS_BLOCK_GROUP_RAID6)) {
>                 get_raid56_logic_offset(physical, num, map, &offset);
> -               increment = map->stripe_len * nr_data_stripes(map);
> +               increment *= nr_data_stripes(map);
>                 mirror_num = 1;
>         } else {
> -               increment = map->stripe_len;
> +               increment *= 1;
Same.
>                 mirror_num = 1;
>         }
>
> --
> 1.7.9.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Have a nice day,
Timofey.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] fs: btrfs: fix potential overflow
  2014-08-24  9:44 ` Timofey Titovets
@ 2014-08-26  6:45   ` Brian Norris
  0 siblings, 0 replies; 4+ messages in thread
From: Brian Norris @ 2014-08-26  6:45 UTC (permalink / raw)
  To: Timofey Titovets; +Cc: Chris Mason, Josef Bacik, linux-btrfs, Linux Kernel

On Sun, Aug 24, 2014 at 12:44:11PM +0300, Timofey Titovets wrote:
> 2014-08-24 8:41 GMT+03:00 Brian Norris <computeaboversforpeace@gmail.com>:
> > --- a/fs/btrfs/scrub.c
> > +++ b/fs/btrfs/scrub.c
> > @@ -2320,26 +2320,26 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
> >         do_div(nstripes, map->stripe_len);
> >         if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
> >                 offset = map->stripe_len * num;
> > -               increment = map->stripe_len * map->num_stripes;
> > +               increment *= map->num_stripes;
> >                 mirror_num = 1;
> >         } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
> >                 int factor = map->num_stripes / map->sub_stripes;
> >                 offset = map->stripe_len * (num / map->sub_stripes);
> > -               increment = map->stripe_len * factor;
> > +               increment *= factor;
> >                 mirror_num = num % map->sub_stripes + 1;
> >         } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
> > -               increment = map->stripe_len;
> > +               increment *= 1;
> Why? I think multiple by one is useless or i miss something?

A misguided attempt to keep the code structure intact. I'll drop these
for v2.

[snip]

Thanks,
Brian

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v2] fs: btrfs: fix potential overflow
  2014-08-24  5:41 [PATCH] fs: btrfs: fix potential overflow Brian Norris
  2014-08-24  9:44 ` Timofey Titovets
@ 2014-08-26  6:47 ` Brian Norris
  1 sibling, 0 replies; 4+ messages in thread
From: Brian Norris @ 2014-08-26  6:47 UTC (permalink / raw)
  To: Chris Mason; +Cc: Josef Bacik, linux-btrfs, Linux Kernel, Timofey Titovets

It looks like this intended to be 64-bit arithmetic, but it's actually
performed as 32-bit. Fix that. (Note that 'increment' was being
initialized twice, so this patch removes one of those.)

Caught by Coverity Scan (CID 1201422).

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
v2: remove useless multiplication-by-one

Untested

 fs/btrfs/scrub.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index b6d198f5181e..e38933ebf97f 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2320,26 +2320,23 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	do_div(nstripes, map->stripe_len);
 	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
 		offset = map->stripe_len * num;
-		increment = map->stripe_len * map->num_stripes;
+		increment *= map->num_stripes;
 		mirror_num = 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
 		int factor = map->num_stripes / map->sub_stripes;
 		offset = map->stripe_len * (num / map->sub_stripes);
-		increment = map->stripe_len * factor;
+		increment *= factor;
 		mirror_num = num % map->sub_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
-		increment = map->stripe_len;
 		mirror_num = num % map->num_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-		increment = map->stripe_len;
 		mirror_num = num % map->num_stripes + 1;
 	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
 				BTRFS_BLOCK_GROUP_RAID6)) {
 		get_raid56_logic_offset(physical, num, map, &offset);
-		increment = map->stripe_len * nr_data_stripes(map);
+		increment *= nr_data_stripes(map);
 		mirror_num = 1;
 	} else {
-		increment = map->stripe_len;
 		mirror_num = 1;
 	}
 
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2014-08-26  6:47 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2014-08-24  5:41 [PATCH] fs: btrfs: fix potential overflow Brian Norris
2014-08-24  9:44 ` Timofey Titovets
2014-08-26  6:45   ` Brian Norris
2014-08-26  6:47 ` [PATCH v2] " Brian Norris

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