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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id z5-20020a170903018500b0015e8d4eb223sm7040663plg.109.2022.05.03.18.57.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 May 2022 18:57:46 -0700 (PDT) From: Kees Cook To: "Gustavo A . R . Silva" Cc: Kees Cook , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , xen-devel@lists.xenproject.org, Alexei Starovoitov , alsa-devel@alsa-project.org, Al Viro , Andrew Gabbasov , Andrew Morton , Andy Gross , Andy Lavr , Arend van Spriel , Baowen Zheng , Bjorn Andersson , Bradley Grove , brcm80211-dev-list.pdl@broadcom.com, Christian Brauner , =?utf-8?q?Christian_G=C3=B6ttsche?= , Christian Lamparter , Chris Zankel , Cong Wang , Daniel Axtens , Daniel Vetter , Dan Williams , David Gow , David Howells , "David S. Miller" , Dennis Dalessandro , devicetree@vger.kernel.org, Dexuan Cui , Dmitry Kasatkin , Eli Cohen , Eric Dumazet , Eric Paris , Eugeniu Rosca , Felipe Balbi , Francis Laniel , Frank Rowand , Franky Lin , Greg Kroah-Hartman , Gregory Greenman , Guenter Roeck , Haiyang Zhang , Hante Meuleman , Herbert Xu , Hulk Robot , Jakub Kicinski , "James E.J. Bottomley" , James Morris , Jarkko Sakkinen , Jaroslav Kysela , Jason Gunthorpe , Jens Axboe , Johan Hedberg , Johannes Berg , Johannes Berg , John Keeping , Kalle Valo , Keith Packard , keyrings@vger.kernel.org, kunit-dev@googlegroups.com, Kuniyuki Iwashima , "K. Y. Srinivasan" , Lars-Peter Clausen , Lee Jones , Leon Romanovsky , Liam Girdwood , linux1394-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-bluetooth@vger.kernel.org, linux-hardening@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-integrity@vger.kernel.org, linux-rdma@vger.kernel.org, linux-scsi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-usb@vger.kernel.org, linux-wireless@vger.kernel.org, linux-xtensa@linux-xtensa.org, llvm@lists.linux.dev, Loic Poulain , Louis Peens , Luca Coelho , Luiz Augusto von Dentz , Marc Dionne , Marcel Holtmann , Mark Brown , "Martin K. Petersen" , Max Filippov , Mimi Zohar , Muchun Song , Nathan Chancellor , netdev@vger.kernel.org, Nick Desaulniers , =?utf-8?q?Nuno_S=C3=A1?= , Paolo Abeni , Paul Moore , Rich Felker , Rob Herring , Russell King , selinux@vger.kernel.org, "Serge E. Hallyn" , SHA-cyfmac-dev-list@infineon.com, Simon Horman , Stefan Richter , Steffen Klassert , Stephen Hemminger , Stephen Smalley , Tadeusz Struk , Takashi Iwai , Tom Rix , Udipto Goswami , Vincenzo Frascino , wcn36xx@lists.infradead.org, Wei Liu , Xiu Jianfeng , Yang Yingliang Subject: [PATCH 31/32] xenbus: Use mem_to_flex_dup() with struct read_buffer Date: Tue, 3 May 2022 18:44:40 -0700 Message-Id: <20220504014440.3697851-32-keescook@chromium.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220504014440.3697851-1-keescook@chromium.org> References: <20220504014440.3697851-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1723; h=from:subject; bh=Af40/wtrXz82sQZ3gkXc9sqO1MKE/dCxzKzVkZCyPBE=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBicdqH+KXwBf+62Kz/ptxhFXwkt9WosiEBHko2iuOB 0fcNum2JAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYnHahwAKCRCJcvTf3G3AJvLPD/ 9BhjziZJhS9xD2GsjrelNYz/xp7Z6XtKNgFRofwy/p+e4IFCpDHMNYQmpP3WVjlkD9FyouGOGLk+Sf 0i6cJgn02GGl9DKJH1kqxbUikzY6c8wzuc6v3W7+teBaTIZXxJ4Bg0xxroKqmZVZTUvN34ouMFIb2p ++rnq2J7531VZeebMPx+6kezaUVTaUGe1VFKBUuccT4/6mp2R8HqzWVgmSai8ZyNi4Z0nnObREm+rJ u1d6VjniOCRmOGgG7QCuuF+cUE4d+Isa6moThhkOv0m//DMJYGT/djpuk6W+kWlcJs+nrsoX1AByJu zD1O0Fk/hh4ooTDaA3lQmWtVq+gJIaYvCBILFRlDcGFC0oo/EM3wXTGcFGjgMgTNiEXK62PdLF9dZf kRieucxaOIdVPYz+BN9o4ps+oSWfIYaQYOYAOwTAA01RA6l3cElUd3dfgBE1lOqQNUDIkcTD8rOm+l 8JdhxGwQaeetRebI0mGQru7qvbnW4s+raN3cR8JtJ36LlEBzqobHNRhVRK3K2dZQhOPhKgr3OWpCOE anL307TAv51pZ7CNDf9iEaZPdoVXALMDtkTpnwemX7C4Lc94fH0b/AmlH5YOCpb8DGFa9BJnGzvzbc FPmLrSOPa5hu9l1uVEcpEaQHDzIfRLtxISX0mmsQ1VLswRk+mwBJcKd8a+7w== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org As part of the work to perform bounds checking on all memcpy() uses, replace the open-coded a deserialization of bytes out of memory into a trailing flexible array by using a flex_array.h helper to perform the allocation, bounds checking, and copying. Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Cc: xen-devel@lists.xenproject.org Signed-off-by: Kees Cook --- drivers/xen/xenbus/xenbus_dev_frontend.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c index 597af455a522..4267aaef33fb 100644 --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -81,8 +81,8 @@ struct xenbus_transaction_holder { struct read_buffer { struct list_head list; unsigned int cons; - unsigned int len; - char msg[]; + DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(unsigned int, len); + DECLARE_FLEX_ARRAY_ELEMENTS(char, msg); }; struct xenbus_file_priv { @@ -188,21 +188,17 @@ static ssize_t xenbus_file_read(struct file *filp, */ static int queue_reply(struct list_head *queue, const void *data, size_t len) { - struct read_buffer *rb; + struct read_buffer *rb = NULL; if (len == 0) return 0; if (len > XENSTORE_PAYLOAD_MAX) return -EINVAL; - rb = kmalloc(sizeof(*rb) + len, GFP_KERNEL); - if (rb == NULL) + if (mem_to_flex_dup(&rb, data, len, GFP_KERNEL)) return -ENOMEM; rb->cons = 0; - rb->len = len; - - memcpy(rb->msg, data, len); list_add_tail(&rb->list, queue); return 0;