Re: EBPF-triggered WARNING at mm/percpu.c:1361 in v4-14-rc2

2017-09-28 Thread Daniel Borkmann
On 09/28/2017 04:45 PM, Mark Rutland wrote: On Thu, Sep 28, 2017 at 04:37:46PM +0200, Daniel Borkmann wrote: On 09/28/2017 01:27 PM, Mark Rutland wrote: Hi, While fuzzing v4.14-rc2 with Syzkaller, I found it was possible to trigger the warning at mm/percpu.c:1361, on both arm64 and x86_64.

Re: EBPF-triggered WARNING at mm/percpu.c:1361 in v4-14-rc2

2017-09-28 Thread Tejun Heo
Hello, On Thu, Sep 28, 2017 at 03:45:38PM +0100, Mark Rutland wrote: > > Perhaps the pr_warn() should be ratelimited; or could there be an > > option where we only return NULL, not triggering a warn at all (which > > would likely be what callers might do anyway when checking against > >

Re: EBPF-triggered WARNING at mm/percpu.c:1361 in v4-14-rc2

2017-09-28 Thread Tejun Heo
Hello, On Thu, Sep 28, 2017 at 12:27:28PM +0100, Mark Rutland wrote: > diff --git a/mm/percpu.c b/mm/percpu.c > index 59d44d6..f731c45 100644 > --- a/mm/percpu.c > +++ b/mm/percpu.c > @@ -1355,8 +1355,13 @@ static void __percpu *pcpu_alloc(size_t size, size_t > align, bool reserved, >

Re: EBPF-triggered WARNING at mm/percpu.c:1361 in v4-14-rc2

2017-09-28 Thread Mark Rutland
On Thu, Sep 28, 2017 at 04:37:46PM +0200, Daniel Borkmann wrote: > On 09/28/2017 01:27 PM, Mark Rutland wrote: > >Hi, > > > >While fuzzing v4.14-rc2 with Syzkaller, I found it was possible to trigger > >the > >warning at mm/percpu.c:1361, on both arm64 and x86_64. This appears to > >require >

Re: EBPF-triggered WARNING at mm/percpu.c:1361 in v4-14-rc2

2017-09-28 Thread Daniel Borkmann
On 09/28/2017 01:27 PM, Mark Rutland wrote: Hi, While fuzzing v4.14-rc2 with Syzkaller, I found it was possible to trigger the warning at mm/percpu.c:1361, on both arm64 and x86_64. This appears to require increasing RLIMIT_MEMLOCK, so to the best of my knowledge this cannot be triggered by an