* array bounds warning in xfrm_output_resume
@ 2018-06-18 18:10 David Ahern
2018-06-19 8:11 ` Florian Westphal
2018-09-19 16:57 ` David Ahern
0 siblings, 2 replies; 6+ messages in thread
From: David Ahern @ 2018-06-18 18:10 UTC (permalink / raw)
To: Florian Westphal; +Cc: netdev@vger.kernel.org
Florian:
I am seeing this warning:
$ make O=kbuild/perf -j 24 -s
In file included from /home/dsa/kernel-3.git/include/linux/kernel.h:10:0,
from /home/dsa/kernel-3.git/include/linux/list.h:9,
from /home/dsa/kernel-3.git/include/linux/module.h:9,
from /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c:13:
/home/dsa/kernel-3.git/net/xfrm/xfrm_output.c: In function
‘xfrm_output_resume’:
/home/dsa/kernel-3.git/include/linux/compiler.h:252:20: warning: array
subscript is above array bounds [-Warray-bounds]
__read_once_size(&(x), __u.__c, sizeof(x)); \
^~~~
/home/dsa/kernel-3.git/include/linux/compiler.h:258:22: note: in
expansion of macro ‘__READ_ONCE’
#define READ_ONCE(x) __READ_ONCE(x, 1)
^~~~~~~~~~~
/home/dsa/kernel-3.git/include/linux/rcupdate.h:350:48: note: in
expansion of macro ‘READ_ONCE’
typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \
^~~~~~~~~
/home/dsa/kernel-3.git/include/linux/rcupdate.h:487:2: note: in
expansion of macro ‘__rcu_dereference_check’
__rcu_dereference_check((p), (c) || rcu_read_lock_held(), __rcu)
^~~~~~~~~~~~~~~~~~~~~~~
/home/dsa/kernel-3.git/include/linux/rcupdate.h:545:28: note: in
expansion of macro ‘rcu_dereference_check’
#define rcu_dereference(p) rcu_dereference_check(p, 0)
^~~~~~~~~~~~~~~~~~~~~
/home/dsa/kernel-3.git/include/linux/netfilter.h:218:15: note: in
expansion of macro ‘rcu_dereference’
hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
^~~~~~~~~~~~~~~
Line in question is the nf_hook in xfrm_output_resume.
NF_INET_POST_ROUTING = 4 which is greater than NF_ARP_NUMHOOKS = 3
I believe ef57170bbfdd6 is the commit that introduced the warning
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: array bounds warning in xfrm_output_resume 2018-06-18 18:10 array bounds warning in xfrm_output_resume David Ahern @ 2018-06-19 8:11 ` Florian Westphal 2018-09-19 16:57 ` David Ahern 1 sibling, 0 replies; 6+ messages in thread From: Florian Westphal @ 2018-06-19 8:11 UTC (permalink / raw) To: David Ahern; +Cc: Florian Westphal, netdev@vger.kernel.org David Ahern <dsahern@gmail.com> wrote: > $ make O=kbuild/perf -j 24 -s > In file included from /home/dsa/kernel-3.git/include/linux/kernel.h:10:0, > from /home/dsa/kernel-3.git/include/linux/list.h:9, > from /home/dsa/kernel-3.git/include/linux/module.h:9, > from /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c:13: > /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c: In function > ‘xfrm_output_resume’: > /home/dsa/kernel-3.git/include/linux/compiler.h:252:20: warning: array > subscript is above array bounds [-Warray-bounds] > __read_once_size(&(x), __u.__c, sizeof(x)); \ > ^~~~ > /home/dsa/kernel-3.git/include/linux/compiler.h:258:22: note: in > expansion of macro ‘__READ_ONCE’ > #define READ_ONCE(x) __READ_ONCE(x, 1) > ^~~~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/rcupdate.h:350:48: note: in > expansion of macro ‘READ_ONCE’ > typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \ > ^~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/rcupdate.h:487:2: note: in > expansion of macro ‘__rcu_dereference_check’ > __rcu_dereference_check((p), (c) || rcu_read_lock_held(), __rcu) > ^~~~~~~~~~~~~~~~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/rcupdate.h:545:28: note: in > expansion of macro ‘rcu_dereference_check’ > #define rcu_dereference(p) rcu_dereference_check(p, 0) > ^~~~~~~~~~~~~~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/netfilter.h:218:15: note: in > expansion of macro ‘rcu_dereference’ > hook_head = rcu_dereference(net->nf.hooks_arp[hook]); Hmpf. compiler can't know that this is only called for ipv4 and ipv6 families. > Line in question is the nf_hook in xfrm_output_resume. > NF_INET_POST_ROUTING = 4 which is greater than NF_ARP_NUMHOOKS = 3 > > I believe ef57170bbfdd6 is the commit that introduced the warning Yes. I will see how to best fix this, probably needs an explicit check on skb_dst(skb)->ops->family. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: array bounds warning in xfrm_output_resume 2018-06-18 18:10 array bounds warning in xfrm_output_resume David Ahern 2018-06-19 8:11 ` Florian Westphal @ 2018-09-19 16:57 ` David Ahern 2018-09-19 17:45 ` Florian Westphal 2018-09-20 14:06 ` Florian Westphal 1 sibling, 2 replies; 6+ messages in thread From: David Ahern @ 2018-09-19 16:57 UTC (permalink / raw) To: Florian Westphal; +Cc: netdev@vger.kernel.org On 6/18/18 11:10 AM, David Ahern wrote: > Florian: > > I am seeing this warning: > > $ make O=kbuild/perf -j 24 -s > In file included from /home/dsa/kernel-3.git/include/linux/kernel.h:10:0, > from /home/dsa/kernel-3.git/include/linux/list.h:9, > from /home/dsa/kernel-3.git/include/linux/module.h:9, > from /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c:13: > /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c: In function > ‘xfrm_output_resume’: > /home/dsa/kernel-3.git/include/linux/compiler.h:252:20: warning: array > subscript is above array bounds [-Warray-bounds] > __read_once_size(&(x), __u.__c, sizeof(x)); \ > ^~~~ > /home/dsa/kernel-3.git/include/linux/compiler.h:258:22: note: in > expansion of macro ‘__READ_ONCE’ > #define READ_ONCE(x) __READ_ONCE(x, 1) > ^~~~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/rcupdate.h:350:48: note: in > expansion of macro ‘READ_ONCE’ > typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \ > ^~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/rcupdate.h:487:2: note: in > expansion of macro ‘__rcu_dereference_check’ > __rcu_dereference_check((p), (c) || rcu_read_lock_held(), __rcu) > ^~~~~~~~~~~~~~~~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/rcupdate.h:545:28: note: in > expansion of macro ‘rcu_dereference_check’ > #define rcu_dereference(p) rcu_dereference_check(p, 0) > ^~~~~~~~~~~~~~~~~~~~~ > /home/dsa/kernel-3.git/include/linux/netfilter.h:218:15: note: in > expansion of macro ‘rcu_dereference’ > hook_head = rcu_dereference(net->nf.hooks_arp[hook]); > ^~~~~~~~~~~~~~~ > > Line in question is the nf_hook in xfrm_output_resume. > NF_INET_POST_ROUTING = 4 which is greater than NF_ARP_NUMHOOKS = 3 > > I believe ef57170bbfdd6 is the commit that introduced the warning > Hi Florian: I am still seeing this. I realize the compiler is not understanding the conditions properly, but it is a distraction every time I do a kernel build on Debian Stretch having to filter the above noise from whether I introduce another warning. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: array bounds warning in xfrm_output_resume 2018-09-19 16:57 ` David Ahern @ 2018-09-19 17:45 ` Florian Westphal 2018-09-20 14:06 ` Florian Westphal 1 sibling, 0 replies; 6+ messages in thread From: Florian Westphal @ 2018-09-19 17:45 UTC (permalink / raw) To: David Ahern; +Cc: Florian Westphal, netdev@vger.kernel.org David Ahern <dsahern@gmail.com> wrote: > > I believe ef57170bbfdd6 is the commit that introduced the warning > > > > Hi Florian: > > I am still seeing this. I realize the compiler is not understanding the > conditions properly, but it is a distraction every time I do a kernel > build on Debian Stretch having to filter the above noise from whether I > introduce another warning. Sorry, I forgot about this. I'll look into it tomorrow. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: array bounds warning in xfrm_output_resume 2018-09-19 16:57 ` David Ahern 2018-09-19 17:45 ` Florian Westphal @ 2018-09-20 14:06 ` Florian Westphal 2018-09-20 22:53 ` David Ahern 1 sibling, 1 reply; 6+ messages in thread From: Florian Westphal @ 2018-09-20 14:06 UTC (permalink / raw) To: David Ahern; +Cc: Florian Westphal, netdev@vger.kernel.org David Ahern <dsahern@gmail.com> wrote: > > $ make O=kbuild/perf -j 24 -s > > In file included from /home/dsa/kernel-3.git/include/linux/kernel.h:10:0, > > from /home/dsa/kernel-3.git/include/linux/list.h:9, > > from /home/dsa/kernel-3.git/include/linux/module.h:9, > > from /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c:13: > > /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c: In function > > ‘xfrm_output_resume’: > > /home/dsa/kernel-3.git/include/linux/compiler.h:252:20: warning: array > > subscript is above array bounds [-Warray-bounds] > > __read_once_size(&(x), __u.__c, sizeof(x)); \ Does this thing avoid the warning? diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c --- a/net/xfrm/xfrm_output.c +++ b/net/xfrm/xfrm_output.c @@ -143,6 +143,8 @@ int xfrm_output_resume(struct sk_buff *skb, int err) struct net *net = xs_net(skb_dst(skb)->xfrm); while (likely((err = xfrm_output_one(skb, err)) == 0)) { + unsigned short pf; + nf_reset(skb); err = skb_dst(skb)->ops->local_out(net, skb->sk, skb); @@ -152,11 +154,19 @@ int xfrm_output_resume(struct sk_buff *skb, int err) if (!skb_dst(skb)->xfrm) return dst_output(net, skb->sk, skb); - err = nf_hook(skb_dst(skb)->ops->family, - NF_INET_POST_ROUTING, net, skb->sk, skb, - NULL, skb_dst(skb)->dev, xfrm_output2); - if (unlikely(err != 1)) - goto out; + pf = skb_dst(skb)->ops->family; + switch (pf) { + case AF_INET: /* fallthrough */ + case AF_INET6: + err = nf_hook(pf, + NF_INET_POST_ROUTING, net, skb->sk, skb, + NULL, skb_dst(skb)->dev, xfrm_output2); + if (unlikely(err != 1)) + goto out; + break; + default: + break; + } } if (err == -EINPROGRESS) ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: array bounds warning in xfrm_output_resume 2018-09-20 14:06 ` Florian Westphal @ 2018-09-20 22:53 ` David Ahern 0 siblings, 0 replies; 6+ messages in thread From: David Ahern @ 2018-09-20 22:53 UTC (permalink / raw) To: Florian Westphal; +Cc: netdev@vger.kernel.org On 9/20/18 7:06 AM, Florian Westphal wrote: > David Ahern <dsahern@gmail.com> wrote: >>> $ make O=kbuild/perf -j 24 -s >>> In file included from /home/dsa/kernel-3.git/include/linux/kernel.h:10:0, >>> from /home/dsa/kernel-3.git/include/linux/list.h:9, >>> from /home/dsa/kernel-3.git/include/linux/module.h:9, >>> from /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c:13: >>> /home/dsa/kernel-3.git/net/xfrm/xfrm_output.c: In function >>> ‘xfrm_output_resume’: >>> /home/dsa/kernel-3.git/include/linux/compiler.h:252:20: warning: array >>> subscript is above array bounds [-Warray-bounds] >>> __read_once_size(&(x), __u.__c, sizeof(x)); \ > > Does this thing avoid the warning? nope, still see it. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-09-21 4:39 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-06-18 18:10 array bounds warning in xfrm_output_resume David Ahern 2018-06-19 8:11 ` Florian Westphal 2018-09-19 16:57 ` David Ahern 2018-09-19 17:45 ` Florian Westphal 2018-09-20 14:06 ` Florian Westphal 2018-09-20 22:53 ` David Ahern
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