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Tue, 23 Sep 2025 05:19:53 -0700 (PDT) Date: Tue, 23 Sep 2025 15:19:50 +0300 From: Dan Carpenter To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: Sumit Semwal , Simona Vetter , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] dma-buf: fix reference count leak in dma_buf_poll_add_cb() Message-ID: References: <7bb48401-ed99-4263-addd-ec1462d68168@amd.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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7bb48401-ed99-4263-addd-ec1462d68168@amd.com> On Tue, Sep 23, 2025 at 02:00:28PM +0200, Christian König wrote: > On 23.09.25 13:14, Dan Carpenter wrote: > > Call dma_fence_put(fence) if dma_fence_add_callback() fails. > > Well that change is obviously incorrect. > > When dma_fence_add_callback() fails we already call dma_fence_put() and drop the reference. > > When the dma_fence_add_callback() call succeeds the callback will drop the reference. > > The problem here is that the return code of dma_fence_add_callback() is an integer error code instead of a bool and basically has the reverse meaning than what people usually expect. > Ah, yes. You're exactly correct of course. Sorry about that. regards, dan carpenter