Re: [PATCH v8 bpf-next/net 1/6] tcp: Save lock_sock() for memcg in inet_csk_accept().

On Tue, Sep 16, 2025 at 11:37 PM kernel test robot
[off-list ref] wrote:

Hello,

kernel test robot noticed "BUG:KASAN:slab-out-of-bounds_in__inet_accept" on:

commit: d465aa09942825d93a377c3715c464e8f6827f13 ("[PATCH v8 bpf-next/net 1/6] tcp: Save lock_sock() for memcg in inet_csk_accept().")
url: https://github.com/intel-lab-lkp/linux/commits/Kuniyuki-Iwashima/tcp-Save-lock_sock-for-memcg-in-inet_csk_accept/20250911-032312
base: https://git.kernel.org/cgit/linux/kernel/git/bpf/bpf-next.git net
patch link: https://lore.kernel.org/all/20250910192057.1045711-2-kuniyu@google.com/ (local)
patch subject: [PATCH v8 bpf-next/net 1/6] tcp: Save lock_sock() for memcg in inet_csk_accept().

in testcase: ltp
version: ltp-x86_64-c6660a3e0-1_20250913
with following parameters:

        test: net.features



config: x86_64-rhel-9.4-ltp
compiler: gcc-14
test machine: 8 threads 1 sockets Intel(R) Core(TM) i7-4790T CPU @ 2.70GHz (Haswell) with 16G memory

(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 [off-list ref]
| Closes: https://lore.kernel.org/oe-lkp/202509171359.658ddb38-lkp@intel.com (local)


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250917/202509171359.658ddb38-lkp@intel.com


we saw a lot of "BUG:KASAN:slab-out-of-bounds_in__inet_accept" issue in dmesg
uploaded to above link, below is just one example:


[  468.984291][T30180] ==================================================================
[  468.992753][T30180] BUG: KASAN: slab-out-of-bounds in __inet_accept+0x5c6/0x640

Oh I misused sk_is_mptcp() which assumes that sk_is_tcp()
is always true and should not be used if sk_is_tcp() is false for
SCTP, so sk_is_mptcp() test was unnecessary

I'll remove it, thanks!