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Thu, 13 Aug 2026 07:25:28 +0000 (GMT) Received: from [9.124.209.227] (unknown [9.124.209.227]) by smtpav06.dal12v.mail.ibm.com (Postfix) with ESMTP; Thu, 13 Aug 2026 07:25:28 +0000 (GMT) Message-ID: Date: Thu, 13 Aug 2026 12:55:27 +0530 Precedence: bulk X-Mailing-List: syzbot@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot ci] Re: net/smc: fix clcsock and lgr/lnk races in smc_diag dump path To: syzbot ci , alibuda@linux.alibaba.com, andrew@lunn.ch, davem@davemloft.net, dust.li@linux.alibaba.com, edumazet@google.com, guwen@linux.alibaba.com, horms@kernel.org, kuba@kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, pasic@linux.ibm.com, sidraya@linux.ibm.com, tonylu@linux.alibaba.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com References: <6a75f37d.b50370da.49fe0.001c.GAE@google.com> Content-Language: en-US From: Mahanta Jambigi In-Reply-To: <6a75f37d.b50370da.49fe0.001c.GAE@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Authority-Analysis: v=2.4 cv=XqfK/1F9 c=1 sm=1 tr=0 ts=6a7d7172 cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=-ibLmwfWAAAA:8 a=Oh2cFVv5AAAA:8 a=-ztMTYQJyvQxDNS25zoA:9 a=QEXdDO2ut3YA:10 a=A6MkUVyZPcTV1i89ro0M:22 a=7KeoIwV6GZqOttXkcoxL:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODEzMDA0NyBTYWx0ZWRfX3LFa1D9Pk+Ut pKIP6OwpSXztx78uzh34BKc15FKpJ2Rsy3bJ+PNORjJFh8Yxo6CXqJSKLFppIX82ZXKSMLhiwTf WacmJH+m11f36DPDBd2Y9gHS5J2i/lwB1ui6OBXBrp2j3RYven83t71nOxU0sLo/lr5rOgMpXkk vo3sE3f2f3O8gYLxfHUw9XNC4SZrgLPPWmMzoru8yLSjXYoDRvABQXdVDttrszkmuNqrpDv19CU sWfYMwGhOooudl17XlG+paseSSY2d2M1WH9TpHsuUPvnF2WarnNQZWObBo5hpV6E5sB1N9e7/fd /nOwUHmf3CDf7QW0w37Xmxxi54jBVoPTMrb054LIu5SIZv7qcaDREO5C87lu3dpoIpAdVx70vDs UvgvqUBRkIyNQm2OIXoudlr5yxRMflyI0lKXR48yAVoCWTrq+dzJlUeCCqBm1lTLb5HjOmO/86x GMEgudyOy4oiwshSbyg== X-Proofpoint-ORIG-GUID: ecrSSeiCrI6JpB4BjMy1hoDZ5x7Qi3vg X-Proofpoint-GUID: 1l0aA0Et_vxTxcQjSMcc8oFukKNMbVaj X-Proofpoint-Spam-Info: AW1haW4tMjYwODEzMDA0NyBTYWx0ZWRfX1prPcklBKVuX NQ7Eu2QIjqicjHYBPxqWZG1Fwdi0cpf/ce34ZpU600XdlqOsir1c3c3bMWNX4+UmR61khlOcLcq w3vlqorggATD2VN69DCZp0HM78zpjTY= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-13_02,2026-08-12_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 spamscore=0 adultscore=0 malwarescore=0 clxscore=1011 suspectscore=0 priorityscore=1501 impostorscore=0 phishscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608130047 On 07/08/26 8:32 pm, syzbot ci wrote: > syzbot ci has tested the following series > > [v3] net/smc: fix clcsock and lgr/lnk races in smc_diag dump path > https://lore.kernel.org/all/20260807081606.3200128-1-mjambigi@linux.ibm.com > * [PATCH net v3] net/smc: fix clcsock and lgr/lnk races in smc_diag dump path > > and found the following issue: > WARNING in smc_diag_dump_proto > > Full report is available here: > https://ci.syzbot.org/series/ab0d12fd-741a-4a0f-9f49-e52b84e94f4a > > *** > > WARNING in smc_diag_dump_proto > > tree: net > URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git > base: 594d905195024b228c962627ae5ae7c17bd582a4 > arch: amd64 > compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 > config: https://ci.syzbot.org/builds/0c4d246f-d098-4afe-b6bc-0f0ad52f55f8/config > syz repro: https://ci.syzbot.org/findings/fa5564b8-8db6-4f76-9d75-dbd796435d87/syz_repro > > ------------[ cut here ]------------ > DEBUG_LOCKS_WARN_ON(lock->magic != lock) > WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline], CPU#0: syz.0.161/6326 > WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821, CPU#0: syz.0.161/6326 I have fixed this syzbot issue by submitting a separate fix. I also tested the fix by submitting the patch to syzbot & after that this issue is not seen anymore. One can see the test details with a fixed patch in below link. I'll send that patch separately to netdev shortly. https://ci.syzbot.org/series/ab0d12fd-741a-4a0f-9f49-e52b84e94f4a > Modules linked in: > CPU: 0 UID: 0 PID: 6326 Comm: syz.0.161 Not tainted syzkaller #0 PREEMPT(full) > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 > RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:625 [inline] > RIP: 0010:__mutex_lock+0x12df/0x1550 kernel/locking/mutex.c:821 > Code: de 57 90 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 47 02 00 00 83 3d 45 cc 83 04 00 75 13 48 8d 3d a8 1b 87 04 48 c7 c6 40 f7 ec 8b <67> 48 0f b9 3a 90 e9 75 ee ff ff 90 0f 0b 90 e9 48 f2 ff ff 90 0f > RSP: 0018:ffffc900068c6e40 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888170ffd940 > RDX: 0000000000000000 RSI: ffffffff8becf740 RDI: ffffffff905b2db0 > RBP: ffffc900068c6fd0 R08: ffffffff9057de43 R09: 1ffffffff20afbc8 > R10: dffffc0000000000 R11: fffffbfff20afbc9 R12: ffff8881b1006648 > R13: 0000000000000000 R14: 1ffff92000d18ddc R15: 0000000000000000 > FS: 00007f4dacd826c0(0000) GS:ffff88818d945000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000020000000e000 CR3: 0000000171350000 CR4: 00000000000006f0 > Call Trace: > > smc_diag_msg_common_fill net/smc/smc_diag.c:50 [inline] > __smc_diag_dump net/smc/smc_diag.c:101 [inline] > smc_diag_dump_proto+0x6d2/0x2620 net/smc/smc_diag.c:255 > smc_diag_dump+0x59/0xa0 net/smc/smc_diag.c:278 > netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331 > __netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2446 > netlink_dump_start include/linux/netlink.h:341 [inline] > smc_diag_handler_dump+0x199/0x240 net/smc/smc_diag.c:293 > sock_diag_rcv_msg+0x4b0/0x5f0 net/core/sock_diag.c:-1 > netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 > netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] > netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 > netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 > sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 > __sock_sendmsg net/socket.c:790 [inline] > ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 > ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 > __sys_sendmsg net/socket.c:2770 [inline] > __do_sys_sendmsg net/socket.c:2775 [inline] > __se_sys_sendmsg net/socket.c:2773 [inline] > __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f4dabf9e019 > Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007f4dacd82028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 00007f4dac226090 RCX: 00007f4dabf9e019 > RDX: 0000000000000600 RSI: 0000200000000540 RDI: 0000000000000003 > RBP: 00007f4dac03500c R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007f4dac226128 R14: 00007f4dac226090 R15: 00007ffe0de8ec98