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[47.54.130.67]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8ccea245e56sm14706746d6.43.2026.05.29.04.53.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 May 2026 04:53:36 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wSvmR-00000000SVP-1Len; Fri, 29 May 2026 08:53:35 -0300 Date: Fri, 29 May 2026 08:53:35 -0300 From: Jason Gunthorpe To: Shameer Kolothum Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, nicolinc@nvidia.com, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, nathanc@nvidia.com, mochs@nvidia.com Subject: Re: [PATCH] iommu/tegra241-cmdqv: Skip CMD_SYNC flush during remove Message-ID: <20260529115335.GS2487554@ziepe.ca> References: <20260529091052.317102-1-skolothumtho@nvidia.com> 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: <20260529091052.317102-1-skolothumtho@nvidia.com> On Fri, May 29, 2026 at 10:10:52AM +0100, Shameer Kolothum wrote: > @@ -789,6 +794,13 @@ static void tegra241_cmdqv_remove(struct arm_smmu_device *smmu) > container_of(smmu, struct tegra241_cmdqv, smmu); > u16 idx; > > + /* > + * tegra241_cmdqv_remove() is added to devres at the very beginning. So, > + * at this point, devres has already freed the SMMU resources that this > + * path must not access to avoid a UAF. > + */ > + cmdqv->removing = true; Please don't add random bools to avoid devm bugs. Just don't use devm, or maybe fix the devm ordering.. These ordering bugs are a well known problem with using devm :( Jason