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Wythe" , Dust Li , Sidraya Jayagond , Tony Lu , Wen Gu , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Wenjia Zhang Cc: linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260927073203.3694279-1-nicoyip.dev@gmail.com> Content-Language: en-US From: Mahanta Jambigi In-Reply-To: <20260927073203.3694279-1-nicoyip.dev@gmail.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-Proofpoint-ORIG-GUID: j5QSBf6hnu4gFjl0DmN0HbIBEwuT2KN9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTI4MDAyMiBTYWx0ZWRfXz7pw0chf3PJZ Mb99ouu4dBk2tDRMmi9MF8HiCAe5+NXAfAoEcJaDulLiX3aQxEIdA32BMjDQTQ8eeJUc+BqGj9j btjhUdtRRlSNLk8rliRmghheTOAF/r8Oc11fgk9CBCJYQjjGyoZI+Npa5++bty9MS4T/LHrlDBf NSzD5iZHHX31zMFe/xR44r2N/0NvpDNoR1+ohdrneAv9AtXF/yD4lXIt6rgY+oivJMT9SpKaMbc bt2Vr/zBXaUQgNTq4nbLWp/QcBm3SNjOMfVxqDadO3U+P+JMiNHarflvh5FntOIEC5QZtmtWGME P/AOIlYZiGKJEIOfrJRmGMNCLldLofZmZUECYpfLgmhiGOqQjBLIqcylCzcf2oDjqtHf7kJdbiY 98AWXbl4xxlgNOpN0Imh2lpSp8dydaPEWMrq7pA0sLUQJ1OrellCOVDyfOGpn6HeRwhx0O4RNrL cEmiWc0inUUrMjI1pFA== X-Proofpoint-Spam-Info: AW1haW4tMjYwOTI4MDAyMiBTYWx0ZWRfX3Dd8pCY31Kc9 jXPmu8eyGc3u+ySkiQUHF2lIaIQjOfsMpCk1yHGCRngGm5/4c0Ejxer70523pZz/pQNgfAMn8d4 nHY5CqgbPTSPmpF5UEqwqkkQyylLaOU= X-Authority-Analysis: v=2.4 cv=EY5d0/mC c=1 sm=1 tr=0 ts=6aba01ad cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=IkcTkHD0fZMA:10 a=VdqzKS8jKosA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=B3kcKS1toMKKngqSjDsA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-GUID: 2dlgop4EcxiqUDLEkERlk-6rUzB4D3N_ 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=2026-09-26_05,2026-09-21_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 priorityscore=1501 suspectscore=0 adultscore=0 clxscore=1015 malwarescore=0 impostorscore=0 spamscore=0 lowpriorityscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609280022 On 27/09/26 1:02 pm, Chengfeng Ye wrote: > An SMC-D connection can remain in the socket hash while smc_conn_kill() > tears it down. For devices supporting DMB nocopy, smcd_buf_detach() frees > the send buffer descriptor without taking the hash lock held by the > diagnostic reader. > > __smc_diag_dump() can load a non-NULL conn->sndbuf_desc, then a concurrent > smc_conn_kill() can clear the pointer and free the descriptor before the > dump reads its len field. The socket lock held by the teardown path does > not exclude the dump, and clearing the pointer before freeing it does > not protect a reader that has already loaded it. Agreed. This is addressed in v6[1] by unhashing the socket at the top of smc_conn_kill(), before smcd_buf_detach() runs, so no hashed socket can have its sndbuf_desc freed under a concurrent diag reader. [1] https://lore.kernel.org/netdev/20260926065023.1629497-1-mjambigi@linux.ibm.com/