Hi Borislav, I can confirm your patch working. However, it might be good to use yours and Thomas' in combination to solve this properly.
kind regards Philip On 26.07.2015 10:41, Borislav Petkov wrote: > On Sun, Jul 26, 2015 at 10:13:45AM +0200, Thomas Gleixner wrote: >> On Sun, 26 Jul 2015, Philip Müller wrote: >>>> task: f58e0000 ti: f58e8000 task.ti: f58e800 >>>> EIP: 0060:[<c135a903>] EFLAGS: 00010206 CPU: 0 >>>> EIP is at free_cache_attributes+0x83/0xd0 >>>> EAX: 00000001 EBX: f589d46c ECX: 00000090 EDX: 360c2000 >>>> ESI: 00000000 EDI: c1724a80 EBP: f58e9ec0 ESP: f58e9ea0 >>>> DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 >>>> CR0: 8005003b CR2: 000000ac CR3: 01731000 CR4: 000006d0 >> >> That's a trivial NULL pointer dereference in the error/cleanup >> path. Patch below should fix it. > > Well, I got a bit different, and of course totally untested possible > solution: > > cache_shared_cpu_map_setup() does check sib_cpu_ci->info_list before > setting cpumask bits while cache_shared_cpu_map_remove() doesn't. Ballancing > this out would mean: > > --- > diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c > index 764280a91776..8a4546dc25e3 100644 > --- a/drivers/base/cacheinfo.c > +++ b/drivers/base/cacheinfo.c > @@ -148,7 +148,11 @@ static void cache_shared_cpu_map_remove(unsigned int cpu) > > if (sibling == cpu) /* skip itself */ > continue; > + > sib_cpu_ci = get_cpu_cacheinfo(sibling); > + if (!sib_cpu_ci->info_list) > + continue; > + > sib_leaf = sib_cpu_ci->info_list + index; > cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); > cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); > --- > > Now Philip can have some more fun testing :-) > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/