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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id n21-20020aa78a55000000b0050dc76281c2sm6940054pfa.156.2022.05.03.18.47.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 May 2022 18:47:47 -0700 (PDT) From: Kees Cook To: "Gustavo A . R . Silva" Cc: Kees Cook , Mimi Zohar , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.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 , Boris Ostrovsky , 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 , 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" , Jarkko Sakkinen , Jaroslav Kysela , Jason Gunthorpe , Jens Axboe , Johan Hedberg , Johannes Berg , Johannes Berg , John Keeping , Juergen Gross , 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-rdma@vger.kernel.org, linux-scsi@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 , 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, SHA-cyfmac-dev-list@infineon.com, Simon Horman , Stefano Stabellini , Stefan Richter , Steffen Klassert , Stephen Hemminger , Stephen Smalley , Tadeusz Struk , Takashi Iwai , Tom Rix , Udipto Goswami , Vincenzo Frascino , wcn36xx@lists.infradead.org, Wei Liu , xen-devel@lists.xenproject.org, Xiu Jianfeng , Yang Yingliang Subject: [PATCH 26/32] ima: Use mem_to_flex_dup() with struct modsig Date: Tue, 3 May 2022 18:44:35 -0700 Message-Id: <20220504014440.3697851-27-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=2212; h=from:subject; bh=0OJGwcsHhKZ90NmLpvzscbvuHwuTm4ffAc9aRODTTVY=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBicdqG62vfnuT12WKQv0IVuyRZyZzMX4U3Y+bYmap0 sx6VNCCJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYnHahgAKCRCJcvTf3G3AJp8HEA CsjdGpDagpIubOZwh4SIwzLI0mQ71SVDOmeVgjaMH3wCaEUbVyUbQcZCwMkSSQkmaYi0JHdt186r90 KEdAes66ANgHJSwIbVxb19utRynHoJDFwO5gfVuTp2sVSu0AKP3KnJZajTXsyucbZynSVAJNanMloi v43qXD0nlRXkU0gX5ADpraYNTEc4DmC1I4QdBks60+U4wHFdhcjQvwo5U7V+5dzuva3RK7ldVtXJrB VeE5PpJQ5Xc1tmru3dEvFHv9MKipcoi+cf2u17BgJcgfDnUcb/oIr/jZVk1w2GF8Ilp5rtUyr0DM8m Na/yIL9jeaPARJok7fgLZP9afaRB6ZwWwE4H2uMjCy1cT6gasjHiZsGre3gXlWVcsFQqLjohy6kCxW rBj7pLN4d++yrxKprYmKAt3zeatf5EMTvrLIgqFUOrk/sAwpHwlXmgGTkAeWNhT8J5VVKpaeshrS8f gKI9RgmhD5seOLoAZLEOSns1PPAdryQb5THkD3O+72gLN08L6etoAPODJ68wd7fcwq7Wg5n5/+AkF2 1jkeaI8b1sgNrwkPOtdnKDQm4yxesI//AmfFdH7EEjbVd52gAVu+rbz7yhcBh1dHRczes2IJW3soaR v4zCatjhXz33SY1+Zru2qRrDvhgaoAqzqRxMbwi9eNYoszXDTRyDKQ8NgEFg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: 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: Mimi Zohar Cc: Dmitry Kasatkin Cc: James Morris Cc: "Serge E. Hallyn" Cc: linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org Signed-off-by: Kees Cook --- security/integrity/ima/ima_modsig.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c index fb25723c65bc..200c080d36de 100644 --- a/security/integrity/ima/ima_modsig.c +++ b/security/integrity/ima/ima_modsig.c @@ -28,8 +28,8 @@ struct modsig { * This is what will go to the measurement list if the template requires * storing the signature. */ - int raw_pkcs7_len; - u8 raw_pkcs7[]; + DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(int, raw_pkcs7_len); + DECLARE_FLEX_ARRAY_ELEMENTS(u8, raw_pkcs7); }; /* @@ -42,7 +42,7 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, { const size_t marker_len = strlen(MODULE_SIG_STRING); const struct module_signature *sig; - struct modsig *hdr; + struct modsig *hdr = NULL; size_t sig_len; const void *p; int rc; @@ -65,8 +65,7 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, buf_len -= sig_len + sizeof(*sig); /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */ - hdr = kzalloc(sizeof(*hdr) + sig_len, GFP_KERNEL); - if (!hdr) + if (mem_to_flex_dup(&hdr, buf + buf_len, sig_len, GFP_KERNEL)) return -ENOMEM; hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len); @@ -76,9 +75,6 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, return rc; } - memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len); - hdr->raw_pkcs7_len = sig_len; - /* We don't know the hash algorithm yet. */ hdr->hash_algo = HASH_ALGO__LAST;