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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id n8-20020a170902d2c800b00174d9bbeda4sm6514749plc.197.2022.09.23.13.28.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Sep 2022 13:28:28 -0700 (PDT) From: Kees Cook To: Vlastimil Babka Cc: Kees Cook , Sumit Semwal , =?UTF-8?q?Christian=20K=C3=B6nig?= , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, "Ruhl, Michael J" , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Greg Kroah-Hartman , Nick Desaulniers , Alex Elder , Josef Bacik , David Sterba , Jesse Brandeburg , Daniel Micay , Yonghong Song , Marco Elver , Miguel Ojeda , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, dev@openvswitch.org, x86@kernel.org, llvm@lists.linux.dev, linux-hardening@vger.kernel.org Subject: [PATCH v2 08/16] dma-buf: Proactively round up to kmalloc bucket size Date: Fri, 23 Sep 2022 13:28:14 -0700 Message-Id: <20220923202822.2667581-9-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220923202822.2667581-1-keescook@chromium.org> References: <20220923202822.2667581-1-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Developer-Signature: v=1; a=openpgp-sha256; l=1536; h=from:subject; bh=1k9cluqwH+m+5FA9iHjyZRl7ltBBZL1qz3WU+O4eJDg=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjLhbkkQMIyxW+p5Yq+8oZ2wcfayyBNx+y5dQbw2fi AE/i2oWJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYy4W5AAKCRCJcvTf3G3AJs+QD/ sFhRuVLRx0nMn49LZ3LgzAUGJu/OCv8HKw/plbSsv+vpxeMZ5Y4Z2yz+8pOjvg3cX6lD5EGOFnhfDh AkybvgBPzOD3UBEmc2+orSVNWeDOnYXG/2dyEL7KYashVN5HVyJ+SxZeRk177uhTjBzjbNRkAQ/SVs Oxp1fa8tJlAzSNr4khPvRqKxudlyHIfws9eHam1m+xu9Yx4IaRjlpv73TPFSCF3B4R61s5d9qdqmI6 QtxsboSAw9VmMnwtQ92JY/zE3XF4HhRRzOwCGtrvQkJf7xWir9bHo5kODtv29MGnYSHOD7MNuLNHvy yT9yMlcMCSUI01Gqw83MyXuzCvvbGT8fRIxDuE0OLV8AuytMSMYtLLvmi8aqicaaH1P85zLrbxJ7VQ ibgpFBaDwYITAulUo26Uezs0cpbObE4vDsRPIMUwW8KNHI4PXEY3ej4CfYwEi05WAoQDnHjsKiI3mw NgRo1Knltm0LSiFomNDPAPC2bLhoNZ5ap0NV7jcfaCdq1s+e8i6UWoxTNuvUmvNZIO/WymKW5MaK0w VFLb8zJYoMtYLSQQRa1twKC/oiHyzfBWzmy0upGh1vD2LcXJMTsecq1f9iPUzq0AYRDLPe3zIIPTo5 8qm3uJJ1hdyE1VeTF4mKkOhP+oujwwLKoB9fQmxF1d5+YH73zekSnLGtymEw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Instead of discovering the kmalloc bucket size _after_ allocation, round up proactively so the allocation is explicitly made for the full size, allowing the compiler to correctly reason about the resulting size of the buffer through the existing __alloc_size() hint. Cc: Sumit Semwal Cc: "Christian König" Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Kees Cook --- drivers/dma-buf/dma-resv.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 205acb2c744d..5b0a4b8830ff 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -98,12 +98,17 @@ static void dma_resv_list_set(struct dma_resv_list *list, static struct dma_resv_list *dma_resv_list_alloc(unsigned int max_fences) { struct dma_resv_list *list; + size_t size; - list = kmalloc(struct_size(list, table, max_fences), GFP_KERNEL); + /* Round up to the next kmalloc bucket size. */ + size = kmalloc_size_roundup(struct_size(list, table, max_fences)); + + list = kmalloc(size, GFP_KERNEL); if (!list) return NULL; - list->max_fences = (ksize(list) - offsetof(typeof(*list), table)) / + /* Given the resulting bucket size, recalculated max_fences. */ + list->max_fences = (size - offsetof(typeof(*list), table)) / sizeof(*list->table); return list; -- 2.34.1