From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f77.google.com (mail-oa1-f77.google.com [209.85.160.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F2D13793A9 for ; Fri, 12 Jun 2026 05:52:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781243544; cv=none; b=loJbIy/Rttp15P1fh2qry/48sDnuSH47ehQ2FnwzSCvb+lUbEXSHTmTKeFLMxl6YvSIBm9INHKBxUQAgv35HzqiiMvUgwHazfd+MChsOoR1UhGpSKw6p0PPa8Z6HoXBpdGUp3nNQTtKufPIfnh7fGgYm1+9Kxt7dMIgju/CYWEk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781243544; c=relaxed/simple; bh=oJIJaa+O4wOVvyYdQH6BqJuHIPEKaAXPQ/R22GOt//s=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=CXLRxGZnnFTDzXyn/MKt5/Al4OFY5SbIQaYSkTLhYB66/raHA/hbsb+q+psaOpl5Yiyyn3i0Y6zDlCtW9Ms9qiPIaIPiH4qzChZaFXijjhI6DYXqy15KjI8vVzQh0HfOg+GSAVoZqIwf73Pfn5BqE/dCa+Msfs205dgwGkhrLww= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.160.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oa1-f77.google.com with SMTP id 586e51a60fabf-43d197b99b8so1212135fac.0 for ; Thu, 11 Jun 2026 22:52:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781243542; x=1781848342; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=7sDv0jgw8CQFtr8pABadNiCnrd2MCCO5azBbnZKTICs=; b=DG8Q+IebnPwavkXmEWIl/9ckk/xYe9545xrnvCcoC9BfyBZy4ycO0sVYvsRPwoqL0z C97KtxzTPlCeQI8m15GOwQG74bkOVkN5F6mdZjpDZr/z/zduq3wTHK1o623eQEz0kvwo UqIohzWctXxYNafkWx79RWf1QQ+eSUFARo1KBJeq1CXrQjs2t3Yy4ShLgujrPIAYoeKG 1LpAgHIJV9c1NAVwXHh+skVN/Btcyv4EYsILaWMO09771qKgB5LCUePyp4qIouQq3My9 YmNHgb+0LzRj/Bazv0/Il7DALKRG51GvgZ7949KTzpzDkUTbJTxWSBcGi0av2xciCFio stqw== X-Forwarded-Encrypted: i=1; AFNElJ/5tun4bTLFJ/PgDSH0GP065hgSViAsCbIZbNOxZumATHQ/hJrY/rXXMAoRn6SLGqHdTxB68fc=@vger.kernel.org X-Gm-Message-State: AOJu0Yzf+GWgG4t84dcp26xQa7bhLBS3JSaf0CtjxVriTOjlrciytR62 ODoCw0mgx0scH2wTC7y/ntqGo0IbC9FtzFTSIIjRfsQYu2w6C1nqpEVTMYvaRy57ceANldF1z55 jx/hKoYQvB2eXLuXrICIAMuZERGgFErHHRKBmSARd0Bhi8Yj3DoZ8KBCv3E8= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:603:b0:696:6f52:95f8 with SMTP id 006d021491bc7-69edc5d46e9mr1022071eaf.3.1781243542111; Thu, 11 Jun 2026 22:52:22 -0700 (PDT) Date: Thu, 11 Jun 2026 22:52:22 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a2b9e96.99669fcc.12a77b.0006.GAE@google.com> Subject: [syzbot] [net?] KCSAN: data-race in xfrm_lookup_with_ifid / xfrm_policy_delete From: syzbot To: davem@davemloft.net, edumazet@google.com, herbert@gondor.apana.org.au, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, steffen.klassert@secunet.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 2b414a95b8f7 Merge tag 's390-7.1-5' of git://git.kernel.or.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1085b3d2580000 kernel config: https://syzkaller.appspot.com/x/.config?x=f571f22917457cd8 dashboard link: https://syzkaller.appspot.com/bug?extid=d85ba1c732720b9a4097 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a2bc12f628f8/disk-2b414a95.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/97ba8f79b58e/vmlinux-2b414a95.xz kernel image: https://storage.googleapis.com/syzbot-assets/b78d4c1c5145/bzImage-2b414a95.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d85ba1c732720b9a4097@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in xfrm_lookup_with_ifid / xfrm_policy_delete read-write to 0xffff888134a45934 of 4 bytes by interrupt on cpu 0: __xfrm_policy_unlink net/xfrm/xfrm_policy.c:2340 [inline] xfrm_policy_delete+0x1f7/0x240 net/xfrm/xfrm_policy.c:2360 xfrm_policy_timer+0x280/0x4d0 net/xfrm/xfrm_policy.c:419 call_timer_fn+0x3b/0x240 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x415/0x5f0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0x31/0x70 kernel/time/timer.c:2405 handle_softirqs+0xb9/0x280 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x42/0xd0 kernel/softirq.c:735 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x74/0x80 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705 instrument_read_write include/linux/instrumented.h:56 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1301 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock include/linux/spinlock.h:187 [inline] __raw_spin_lock include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_lock+0x4a/0xa0 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] d_alloc_parallel+0xab/0xce0 fs/dcache.c:2679 __lookup_slow+0x96/0x260 fs/namei.c:1900 lookup_slow+0x3c/0x60 fs/namei.c:1932 walk_component fs/namei.c:2278 [inline] lookup_last fs/namei.c:2785 [inline] path_lookupat+0x2f7/0x500 fs/namei.c:2809 filename_lookup+0x190/0x390 fs/namei.c:2838 vfs_statx+0x96/0x170 fs/stat.c:353 vfs_fstatat+0x118/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat+0x55/0x3e0 fs/stat.c:532 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:532 x64_sys_call+0x2c64/0x3020 arch/x86/include/generated/asm/syscalls_64.h:263 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888134a45934 of 4 bytes by task 9151 on cpu 1: xfrm_lookup_with_ifid+0x5b4/0x1590 net/xfrm/xfrm_policy.c:3225 xfrm_lookup+0x38/0x50 net/xfrm/xfrm_policy.c:3327 icmpv6_route_lookup+0x10b/0x3e0 net/ipv6/icmp.c:381 icmp6_send+0xc63/0x1100 net/ipv6/icmp.c:793 icmpv6_param_prob_reason+0x32/0x50 net/ipv6/icmp.c:848 ip6_tlvopt_unknown net/ipv6/exthdrs.c:94 [inline] ip6_parse_tlv+0xf70/0x1080 net/ipv6/exthdrs.c:-1 ipv6_parse_hopopts+0x1e5/0x320 net/ipv6/exthdrs.c:1084 ip6_rcv_core+0x8e9/0xab0 net/ipv6/ip6_input.c:321 ipv6_list_rcv+0x11f/0x2a0 net/ipv6/ip6_input.c:378 __netif_receive_skb_list_ptype net/core/dev.c:6245 [inline] __netif_receive_skb_list_core+0x3b0/0x500 net/core/dev.c:6292 __netif_receive_skb_list net/core/dev.c:6344 [inline] netif_receive_skb_list_internal+0x47d/0x5f0 net/core/dev.c:6435 netif_receive_skb_list+0x33/0x1c0 net/core/dev.c:6487 xdp_recv_frames net/bpf/test_run.c:269 [inline] xdp_test_run_batch net/bpf/test_run.c:350 [inline] bpf_test_run_xdp_live+0x104c/0x1360 net/bpf/test_run.c:379 bpf_prog_test_run_xdp+0x57b/0xa10 net/bpf/test_run.c:1430 bpf_prog_test_run+0x204/0x340 kernel/bpf/syscall.c:4742 __sys_bpf+0x52e/0x7e0 kernel/bpf/syscall.c:6292 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline] __se_sys_bpf kernel/bpf/syscall.c:6385 [inline] __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6385 x64_sys_call+0x10cb/0x3020 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000001 -> 0x00000000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 9151 Comm: syz.7.9538 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup