Re: [linux-next:master] [net] fed176bf31: KASAN:maybe_wild-memory-access_in_range[#-#]

[Kuniyuki Iwashima <kuniyu@amazon.com>]

From: kernel test robot <oliver.sang@intel.com>
Date: Fri, 18 Apr 2025 16:16:51 +0800
> Hello,
> 
> kernel test robot noticed "KASAN:maybe_wild-memory-access_in_range[#-#]" on:
> 
> commit: fed176bf3143362ac9935e3964949ab6a5c3286b ("net: Add ops_undo_single for module load/unload.")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
> 
> [test failed on linux-next/master 5b37f7bfff3b1582c34be8fb23968b226db71ebd]
> 
> in testcase: boot
> 
> config: x86_64-randconfig-102-20250415
> compiler: gcc-12
> test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> 
> (please refer to attached dmesg/kmsg for entire log/backtrace)
> 
> 
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Closes: https://lore.kernel.org/oe-lkp/202504181511.1c3f23e4-lkp@intel.com
> 
> 
> [   26.592836][    T1]     audit=0
> [   26.593311][    T1]     riscv_isa_fallback=1
> [   26.685729][    T1] systemd[1]: RTC configured in localtime, applying delta of 0 minutes to system time.
> [   26.694368][    T1] systemd[1]: Failed to find module 'autofs4'
> [   26.766891][    T1] NET: Registered PF_INET6 protocol family
> [   26.767880][    T1] Oops: general protection fault, probably for non-canonical address 0xf999959999999999: 0000 [#1] KASAN
> [   26.769508][    T1] KASAN: maybe wild-memory-access in range [0xccccccccccccccc8-0xcccccccccccccccf]

It reproduced with NET_NS=n.

During boot, first_device->{prev,next} are suddenly changed to
0xcccccccccccccccc, which looks confusing but it was due to
__net_initdata added to struct pernet_operations.

I'll post a fix.

Thanks for the report!