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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id x12-20020a170902ea8c00b001bb99e188fcsm2170047plb.194.2023.10.03.16.17.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Oct 2023 16:17:46 -0700 (PDT) From: Kees Cook To: "David S. Miller" Cc: Kees Cook , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , Anqi Shen , netdev@vger.kernel.org, "Gustavo A. R. Silva" , Nathan Chancellor , Nick Desaulniers , Tom Rix , syzbot , Jianfeng Tan , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] net/packet: Annotate struct packet_fanout with __counted_by Date: Tue, 3 Oct 2023 16:17:41 -0700 Message-Id: <20231003231740.work.413-kees@kernel.org> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1323; i=keescook@chromium.org; h=from:subject:message-id; bh=GKawqwHl4UULkff2cIaeAmAbzx8aWFIbmG5VLVkLd4I=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlHKEUZGTBGbWEbfQHr5gGx1uBl6q3iB19j5TQ8 4R6/WUoIzCJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZRyhFAAKCRCJcvTf3G3A JiFBEACQ9z6btE2IRqV+dlPimus38QVTJ6TnbqlcqFLxVxfTBnSZPghD/CNiZuVouBKmCGzfc8Q H7Vlcjkf882aG66U6TSBtG2M9ndDjlyMpLwzjHNbD8sRH2f7VmHtLuM11Gsk7NAOMK2EU3uzZy5 la89UC4CnKbQoki7cdi96USYK87HkKEMQ2FoktbUUSt0jDgZopRsieiYMkvhr//uOV/XtuzQPF4 /P9r4qH6Z+cwQmuWV5fRvnAuZ+TtV6P8niy+TMK4u3v0NSyfhgqmzm81x7EEWPcApprDIIp7/Ep E4POegXoG7BGZ10Y216YaD9shGKXtcE8rQHPWfn95/z2HGh8xUrzz9M3VjV4A9KWS6NViF4UmKO TzlldgZ1RssRxTAChOf04lXMhc5VV8HFRnBkW+jIckgMei2klc0+SfeIERirUvcjDj6Hr/QWHvY 4bDW579Wh6lNWVjyQICRm5G3kv9dz3Zgtdwef3NgZqsj2b4Y6p9/dmmbYCZlXZTrzM/0xvhHP/x FD0LlpmYBbed2Um/PQTQHk2Kd0nVWGbNxKB4bLXoGIc1NCecn1nqCO+JuvFMMvlIVQM1WaBtor9 vrrpSr0s9k2fX6DT8MWId6QvSoe5Gni2yDgPb2AJ45TOUfZ1L7CNKBj3cHlIvxEm/uvbxIWDPco tS5hYpJ HBTM8msg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct packet_fanout. Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Willem de Bruijn Cc: Anqi Shen Cc: netdev@vger.kernel.org Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1] Signed-off-by: Kees Cook --- net/packet/internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/packet/internal.h b/net/packet/internal.h index 63f4865202c1..d29c94c45159 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -94,7 +94,7 @@ struct packet_fanout { spinlock_t lock; refcount_t sk_ref; struct packet_type prot_hook ____cacheline_aligned_in_smp; - struct sock __rcu *arr[]; + struct sock __rcu *arr[] __counted_by(max_num_members); }; struct packet_rollover { -- 2.34.1