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Sun, 27 Sep 2026 20:59:29 -0700 (PDT) Received: from hu-pkondeti-hyd.qualcomm.com ([202.46.22.19]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-145ad8e43d2sm25142946c88.12.2026.09.27.20.59.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Sep 2026 20:59:28 -0700 (PDT) Date: Mon, 28 Sep 2026 09:29:24 +0530 From: Pavan Kondeti To: Tejun Heo Cc: Pavankumar Kondeti , Lai Jiangshan , linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] workqueue: Fix NULL current_pwq deref in flush dependency check Message-ID: References: <20260925-wq_flush_dep_fix-v1-1-fc5a9de31828@oss.qualcomm.com> <42a21c8fdeb903d8511a279b5cf2e242@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42a21c8fdeb903d8511a279b5cf2e242@kernel.org> X-Proofpoint-GUID: B5R0wCopoGUU5V-RaSRDaOpEKVqW4Y_f X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTI4MDAxNSBTYWx0ZWRfX6lB3I3BJsTYi zqFdx3U8/WBxF3llfmILSyqQdf4klM/BZ2NlsExPPg8tnyfQAutgRAtflEPA/8NuPMAi8RinDl9 IEQu2XzazPHOrSJU7H1AV8tDe7BhSfc637FNRNDbiy5LfEP+UrMn0Pt451tm/i2zdDUjl5/LUyv Yv8i/X7TbTQkdSUhvYR5fjA+lxyGO0TQwWiRG0gQmee7F6AOyxxtQ+GRMm1K5mTbR44cdYODHDZ AEgj+Mh4YgC/KvpgroEDQsIUBYgz4z5LIgM2pKVqBy6TXo6J2qyV6d/C9wHwWzTTVh1cwes8fyD HR6Mjbwj0BvnHuUxCrFKbgheuxLFSa4Zo3UpcXbUXj3XMMk6PGg9m2zSGNOTVci0kV8jxfS1vSS XX1T2Et191oegh+dvevCOR0xyzLq1137O0jr3voBnw6ji8RswaC900btqCXXEbEiyiK8vDu6ptc juFDxja8y685ke1YYhw== X-Proofpoint-Spam-Info: AW1haW4tMjYwOTI4MDAxNSBTYWx0ZWRfXwfUFdQZBCeNx c0asGcoBACqkAnzqTLu1FQOE8KixE3mccA2BjFJT5k9HCRNnYigQ/+7vwdlslIz5HcIiAUHbo7I Ih15X6K1XIHmlA+RbRJkQBTkGwLS0dA= X-Proofpoint-ORIG-GUID: B5R0wCopoGUU5V-RaSRDaOpEKVqW4Y_f X-Authority-Analysis: v=2.4 cv=MqLHeGae c=1 sm=1 tr=0 ts=6ab9e622 cx=c_pps a=JYo30EpNSr/tUYqK9jHPoA==:117 a=fChuTYTh2wq5r3m49p7fHw==:17 a=kj9zAlcOel0A:10 a=VdqzKS8jKosA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=_K5XuSEh1TEqbUxoQ0s3:22 a=OfcC1_vaJly9iBgxsTsA:9 a=CjuIK1q_8ugA:10 a=zgiPjhLxNE0A:10 a=Fk4IpSoW4aLDllm1B1p-:22 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 malwarescore=0 lowpriorityscore=0 suspectscore=0 impostorscore=0 phishscore=0 adultscore=0 clxscore=1015 priorityscore=1501 spamscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609280015 On Sat, Sep 26, 2026 at 10:30:46PM -1000, Tejun Heo wrote: > Applied to wq/for-7.3-fixes. > > - is_chained_work() has the same problem. It dereferences > worker->current_pwq after checking only worker. It is only reached when > queueing on a draining or destroying workqueue, but a kworker outside a > work item would crash there the same way. Can you send a fix for that > one too? > Thanks Tejun. I have sent the fix for is_chained_work() and CC'd stable. I have also sent a separate fix to cover current_is_workqueue_mem_reclaim() which is exported but there is only one user (NFS). It does not appear to me that this can be triggered from NFS code path, so for now I did not copy stable for this patch. Thanks, Pavan