* [PATCH] nft: nft_set_attr_get_u32 null pointer deref
@ 2013-10-25 16:55 Phil Oester
2013-10-27 20:34 ` Pablo Neira Ayuso
0 siblings, 1 reply; 3+ messages in thread
From: Phil Oester @ 2013-10-25 16:55 UTC (permalink / raw)
To: netfilter-devel; +Cc: pablo
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As reported by John Sager, nft_set_attr_get_u32 can cause a segfault because
nft_set_attr_get can return NULL. Check for a non-NULL pointer before
dereferencing.
This closes netfilter bugzilla #868.
Signed-off-by: Phil Oester <kernel@linuxace.com>
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diff --git a/src/set.c b/src/set.c
index 74ec1e3..85f73cf 100644
--- a/src/set.c
+++ b/src/set.c
@@ -183,8 +183,8 @@ EXPORT_SYMBOL(nft_set_attr_get_str);
uint32_t nft_set_attr_get_u32(struct nft_set *s, uint16_t attr)
{
- uint32_t val = *((uint32_t *)nft_set_attr_get(s, attr));
- return val;
+ const void *val = nft_set_attr_get(s, attr);
+ return val ? *(uint32_t *)val : 0;
}
EXPORT_SYMBOL(nft_set_attr_get_u32);
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] nft: nft_set_attr_get_u32 null pointer deref
2013-10-25 16:55 [PATCH] nft: nft_set_attr_get_u32 null pointer deref Phil Oester
@ 2013-10-27 20:34 ` Pablo Neira Ayuso
2013-10-27 23:29 ` Phil Oester
0 siblings, 1 reply; 3+ messages in thread
From: Pablo Neira Ayuso @ 2013-10-27 20:34 UTC (permalink / raw)
To: Phil Oester; +Cc: netfilter-devel
On Fri, Oct 25, 2013 at 09:55:31AM -0700, Phil Oester wrote:
> As reported by John Sager, nft_set_attr_get_u32 can cause a segfault because
> nft_set_attr_get can return NULL. Check for a non-NULL pointer before
> dereferencing.
>
> This closes netfilter bugzilla #868.
I have mangled this patch to include possible null dereferences in get
operations with rule objects (similar case). Let me know if you see
any issue with my change.
Applied, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] nft: nft_set_attr_get_u32 null pointer deref
2013-10-27 20:34 ` Pablo Neira Ayuso
@ 2013-10-27 23:29 ` Phil Oester
0 siblings, 0 replies; 3+ messages in thread
From: Phil Oester @ 2013-10-27 23:29 UTC (permalink / raw)
To: Pablo Neira Ayuso; +Cc: netfilter-devel
On Sun, Oct 27, 2013 at 09:34:26PM +0100, Pablo Neira Ayuso wrote:
> I have mangled this patch to include possible null dereferences in get
> operations with rule objects (similar case). Let me know if you see
> any issue with my change.
Looks good, thanks.
Phil
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-10-25 16:55 [PATCH] nft: nft_set_attr_get_u32 null pointer deref Phil Oester
2013-10-27 20:34 ` Pablo Neira Ayuso
2013-10-27 23:29 ` Phil Oester
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