From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f80.google.com (mail-oa1-f80.google.com [209.85.160.80]) (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 95948255F2D for ; Fri, 29 May 2026 10:51:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780051890; cv=none; b=LdYIMw/Q96pUD6oolzyoYJP04DScajxRi44hMgPWlrd9w1i6YQRweLH6bivyovRFj83lomWH7RH6t0FJhtG6JhfbbRYNLoe4+sw3QfGbbCmwQUTFNfRQPPbfH0pH0d6zMaL41F2uIPATkPQnklEo6c4/gWCjcpP2Yg1RXcdILKI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780051890; c=relaxed/simple; bh=m9K2gAT1s9pLnmlCXZPSvIpdh+VMVFWNKunD/EJAU8s=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=B4xqCi2Fv62ijcpCWLCUMMVZ5Dm0hfCVFRzEqncaRww8kr9IM3Dc/eSqYnvU/q28dAx1OObmV6761rRRU20EKwreYUYlFTfyUQWRI5nrklwdgYVj3ZlZsmmb6OcWLIgmluLvfUY7dSdamJ994UYExlqF5KALGs6SlY/0RzsjCi0= 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=209.85.160.80 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-f80.google.com with SMTP id 586e51a60fabf-43b472c3a38so14789686fac.1 for ; Fri, 29 May 2026 03:51:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780051887; x=1780656687; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Me4SIojYXmgVa1abLeE4WDtQzl3d8au5fzFAB6sRCJY=; b=XvAnHa5PpA3XT7LIDe9ka530H1DbK5Ee23jD4PSaW/54Shq1XgaqGuFNdQE2rb/08C daamJq5g21gxr7s+JrZocSfymUSRk4UAmpkSMUpJYix7Iabo4AmFRuay7DgWP1b0pfWn 4+P2Jramun9/eVe9/BfK9HFgtyhKoHEWNDN2iGE9hyru/GQO5LeqQBxNOP8d9BQzGQBD kECgm0HQoCRC83w+dojLsnywFQvoSxjf+MipCV3dTstLbSKPRM6A6zn7w/zisEZ+t46k ew/+YnWDG/te6dvczYGgjEB/mtmkdoTZn0AKHyy4GAff3v7ouR3kgjzdf5a+LFy3vFxc QjQw== X-Forwarded-Encrypted: i=1; AFNElJ9eI2Gn7JP6IWoV5B7oAMis8PkiP8eWadkROQ6cV3eLtEhIP+csdwjoB2fvdtRlICGeFpH3+fs=@vger.kernel.org X-Gm-Message-State: AOJu0YwMzsT+5vSmAOP2UxlXhYksbKxW+ePTg1CdNKls5fLO/npnop2H xsb0g3IBuYDzbcL1PULQCa0JaQ4qg731J0uV/pCVsrpLKCX8XcKPhpSn4BjBoThEVA5KAtYRt91 RJdgYWR4GW+1eQNfx/+FL978hFtTowiKW4QKAxOj1Wi/puqrhn8wkH2HqdJo= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:7608:b0:69e:5d9:7e49 with SMTP id 006d021491bc7-69e05d98633mr799983eaf.34.1780051887642; Fri, 29 May 2026 03:51:27 -0700 (PDT) Date: Fri, 29 May 2026 03:51:27 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a196faf.c16d89a8.217f2c.0002.GAE@google.com> Subject: [syzbot] [net?] KMSAN: uninit-value in __fl_lookup (3) From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, jhs@mojatatu.com, jiri@resnulli.us, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 6a97c4d5262d Merge tag 'for-linus' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=131bdb06580000 kernel config: https://syzkaller.appspot.com/x/.config?x=91978e795dcd971b dashboard link: https://syzkaller.appspot.com/bug?extid=fa2f5b1fb06147be5e16 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/e37d654ca33b/disk-6a97c4d5.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/dac2f748909e/vmlinux-6a97c4d5.xz kernel image: https://storage.googleapis.com/syzbot-assets/800a8a09004d/bzImage-6a97c4d5.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fa2f5b1fb06147be5e16@syzkaller.appspotmail.com syzkaller0: entered promiscuous mode syzkaller0: entered allmulticast mode ===================================================== BUG: KMSAN: uninit-value in __rht_ptr_rcu include/linux/rhashtable.h:388 [inline] BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:631 [inline] BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:671 [inline] BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:709 [inline] BUG: KMSAN: uninit-value in __fl_lookup+0x6ce/0x940 net/sched/cls_flower.c:269 __rht_ptr_rcu include/linux/rhashtable.h:388 [inline] __rhashtable_lookup include/linux/rhashtable.h:631 [inline] rhashtable_lookup include/linux/rhashtable.h:671 [inline] rhashtable_lookup_fast include/linux/rhashtable.h:709 [inline] __fl_lookup+0x6ce/0x940 net/sched/cls_flower.c:269 fl_mask_lookup+0x305/0xd60 net/sched/cls_flower.c:302 fl_classify+0x36b/0x780 net/sched/cls_flower.c:349 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 multiq_classify net/sched/sch_multiq.c:39 [inline] multiq_enqueue+0x82/0x5a0 net/sched/sch_multiq.c:66 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2698 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2787 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x134/0x390 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: fl_set_masked_key net/sched/cls_flower.c:194 [inline] fl_mask_lookup+0x254/0xd60 net/sched/cls_flower.c:298 fl_classify+0x36b/0x780 net/sched/cls_flower.c:349 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 multiq_classify net/sched/sch_multiq.c:39 [inline] multiq_enqueue+0x82/0x5a0 net/sched/sch_multiq.c:66 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2698 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2787 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x134/0x390 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: __skb_flow_dissect+0xfdb/0xa060 net/core/flow_dissector.c:1182 skb_flow_dissect include/linux/skbuff.h:1603 [inline] fl_classify+0x349/0x780 net/sched/cls_flower.c:346 tc_classify include/net/tc_wrapper.h:198 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x855/0x1ca0 net/sched/cls_api.c:1860 multiq_classify net/sched/sch_multiq.c:39 [inline] multiq_enqueue+0x82/0x5a0 net/sched/sch_multiq.c:66 dev_qdisc_enqueue net/core/dev.c:4174 [inline] __dev_xmit_skb net/core/dev.c:4289 [inline] __dev_queue_xmit+0x23c3/0x5a00 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] packet_xmit+0x8f/0x710 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3082 [inline] packet_sendmsg+0x8c6b/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2698 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2787 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x134/0x390 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4577 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_node_noprof+0x3cd/0x12c0 mm/slub.c:4951 kmalloc_reserve net/core/skbuff.c:613 [inline] __alloc_skb+0x855/0x1190 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xc5/0x990 net/core/skbuff.c:6743 sock_alloc_send_pskb+0xacb/0xc60 net/core/sock.c:2998 packet_alloc_skb net/packet/af_packet.c:2932 [inline] packet_snd net/packet/af_packet.c:3025 [inline] packet_sendmsg+0x6ed5/0x9d60 net/packet/af_packet.c:3114 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2698 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2787 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x134/0x390 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 1 UID: 0 PID: 13869 Comm: syz.9.1335 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 ===================================================== --- 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