lkml.org 
[lkml]   [2021]   [Nov]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [gcov] 1391efa952: BUG:KASAN:slab-out-of-bounds_in_gcov_info_add
From
Date
On Thu, 2021-11-25 at 14:26 +0000, Sang, Oliver wrote:
>
> Greeting,
>
> FYI, we noticed the following commit (built with clang-14):
>
> commit: 1391efa952e8b22088f8626fc63ade26767b92d6 ("gcov: use kvmalloc()")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>
> in testcase: boot
>
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
>
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
>

I don't think it actually *caused* the issue, but who knows? To me it
rather looks like it exposed an issue, which wasn't noticed before
because vmalloc() always allocates a page anyway? Assuming KASAN doesn't
track vmalloc() allocations more granular than their actual page-aligned
memory size (though perhaps it should?)

In any case, reviewing my commit again I see nothing wrong there, and I
don't understand the code/clang well enough to see what might be the
issue.

johannes

\
 
 \ /
  Last update: 2021-11-25 16:54    [W:0.048 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site