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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id a6-20020aa795a6000000b0053abb15b3d9sm7492138pfk.19.2022.09.23.20.52.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Sep 2022 20:52:28 -0700 (PDT) From: Kees Cook To: Christine Caulfield Cc: Kees Cook , David Teigland , cluster-devel@redhat.com, "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] dlm: Split memcpy() of struct dlm_message flexible array Date: Fri, 23 Sep 2022 20:52:26 -0700 Message-Id: <20220924035226.3359297-1-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1267; h=from:subject; bh=e/Y6GTN0SCVQ259nA/pYwlFozQeGo0Cl6K1VpFhG2NE=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjLn75X8LVs9287oq0AOqk6fbfl+f5Dh2O94OSeNFT BKSCt3iJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYy5++QAKCRCJcvTf3G3AJtFrD/ 9Auvgp4BKi9bKLLuhvLc/e/O1WDJsOFfuNo6xlL0Xxa1D97BC+ujNjbyj/GdCB94rJesYm9EjqgR9r pElxGT9NyZ+UiAThiQZEwy7SLXa2Yo6qq5eR99rppLpm1JtU/SduOCUqUEc06k6AqNBizpJyLwwTXz t12Mn9xZYWjzZrgr7syXWkFSjQAIqiy3xmDbYeFZzRc3SyWbu/K3jCrJwZfRFnxCngJ9dKHtvLBsCU 4lFASXpkFsPGvWy51J3wAFTccWeqg7u/mJLIq6sG8N+MWUXVqOkdSBReA/koc21tIknyinJKvhcxc1 vy9iRiQrEhG4czlnJStU2wv/YK48Jrz9jpvPWGgioWkGeHj9GX9IvcN5vJES/4uyJRe+y3QGops8Ch m3Vtm9AviVzNO6hkLBFgNbE9QyFjp6DfNJerwNrn9X4TN9M0heZmNkLDtM9wEMzFa/2ebOUauYzcIk llXFIXE74Xmfn+hAs2gwW8CI6CDVe7pQsC8Eew2fri1vXFtJjwV/Lg3/wzpxxKKixCoN/J1Z/ZoFqz OmE08kuUfMPGbCE+dfkMRt5a7aD0xuSrbTzIhnLa4R1r6m2y/j2/RBofyLao1CpX1tRBbVmka+bLBh BpYILJHURIleLwR3p8UBMg5WMtI9M+UzAFy4NhXoWCkDr12hhvS3tpk1BiEQ== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" To work around a misbehavior of the compiler's ability to see into composite flexible array structs (as detailed in the coming memcpy() hardening series[1]), split the memcpy() of the header and the payload so no false positive run-time overflow warning will be generated. [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keesco= ok@chromium.org/ Cc: Christine Caulfield Cc: David Teigland Cc: cluster-devel@redhat.com Reported-by: "Gustavo A. R. Silva" Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva --- fs/dlm/requestqueue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/dlm/requestqueue.c b/fs/dlm/requestqueue.c index 036a9a0078f6..63f45c3c53a2 100644 --- a/fs/dlm/requestqueue.c +++ b/fs/dlm/requestqueue.c @@ -44,7 +44,8 @@ void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, = struct dlm_message *ms) =20 e->recover_seq =3D ls->ls_recover_seq & 0xFFFFFFFF; e->nodeid =3D nodeid; - memcpy(&e->request, ms, le16_to_cpu(ms->m_header.h_length)); + e->request =3D *ms; + memcpy(&e->request.m_extra, ms->m_extra, length); =20 atomic_inc(&ls->ls_requestqueue_cnt); mutex_lock(&ls->ls_requestqueue_mutex); --=20 2.34.1