{"id":3979,"url":"https://patchwork.libcamera.org/api/patches/3979/?format=json","web_url":"https://patchwork.libcamera.org/patch/3979/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20200607143012.17752-3-email@uajain.com>","date":"2020-06-07T14:30:18","name":"[libcamera-devel,v3,2/2] libcamera: ipa_module: Fix implicit sign-extension in elfSection","commit_ref":"79d666247182b0e42560ab505c29173ca94bdbb0","pull_url":null,"state":"accepted","archived":false,"hash":"f72735bdbfac6fefa1d49a22aaa0d8b083fe6b2c","submitter":{"id":1,"url":"https://patchwork.libcamera.org/api/people/1/?format=json","name":"Umang Jain","email":"email@uajain.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/3979/mbox/","series":[{"id":967,"url":"https://patchwork.libcamera.org/api/series/967/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=967","date":"2020-06-07T14:30:17","name":"Fix implicit sign extension","version":3,"mbox":"https://patchwork.libcamera.org/series/967/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/3979/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/3979/checks/","tags":{},"headers":{"Return-Path":"","Received":["from o1.f.az.sendgrid.net (o1.f.az.sendgrid.net [208.117.55.132])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id DB45F61626\n\tfor ;\n\tSun, 7 Jun 2020 16:30:20 +0200 (CEST)","by filter0135p3las1.sendgrid.net with SMTP id\n\tfilter0135p3las1-9010-5EDCF9FA-1E7\n\t2020-06-07 14:30:18.733685738 +0000 UTC m=+400000.314394105","from mail.uajain.com (unknown)\n\tby ismtpd0004p1maa1.sendgrid.net (SG) with ESMTP\n\tid hZX9YxZ2QLakbeVOk4GZ1A Sun, 07 Jun 2020 14:30:18.366 +0000 (UTC)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=uajain.com\n\theader.i=@uajain.com header.b=\"ilUeU8Yt\"; \n\tdkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=uajain.com;\n\th=from:subject:in-reply-to:references:mime-version:to:cc:\n\tcontent-transfer-encoding:content-type;\n\ts=s1; bh=TBjKum+DY72wRVegSwltHxRqXC6J1KGz1NRSRIej3YA=;\n\tb=ilUeU8YtnH9Hm/d93w7cqE3Ub6v05B/h962j3OLBHket7cQ+c26OPakAl6YHH9yXJ2gx\n\tAoGe2JU9ZBMUIpZZjVYcC70oct4vYkKaajRNb6Nu9ibwk2FhUL6xumhoiBzLYVAIpb+yES\n\tM+u7+LM4bNcFOzxDNXEc82oFuteyzNxVY=","From":"Umang Jain ","Date":"Sun, 07 Jun 2020 14:30:18 +0000 (UTC)","Message-Id":"<20200607143012.17752-3-email@uajain.com>","In-Reply-To":"<20200607143012.17752-1-email@uajain.com>","References":"<20200607143012.17752-1-email@uajain.com>","Mime-Version":"1.0","X-SG-EID":"1Q40EQ7YGir8a9gjSIAdTjhngY657NMk9ckeo4dbHZDiOpywc/L3L9rFqlwE4KPcAl6MTtKrYqN2BGXS9ZDVMf59817yL7+3nHWtUAHR16ne0RQ/mUc/NqTkjCEkd4+DGgj+PD3r5a3rDZOXWMtKRFLnYILa6UC3bnQ8P6hJpXmdvr3TSOLz3jLmvSOR51R92r8OXVUboaIHWmksjTjZXoG/OpGi1c8GL7EwSbFK4Ytdb3/oHKCNGMXxSRsnOHOR","To":"laurent.pinchart@ideasonboard.com, libcamera-devel@lists.libcamera.org, \n\tkieran.bingham@ideasonboard.com","Content-Transfer-Encoding":"7bit","Content-Type":"text/plain; charset=us-ascii","Subject":"[libcamera-devel] [PATCH v3 2/2] libcamera: ipa_module: Fix\n\timplicit sign-extension in elfSection","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Sun, 07 Jun 2020 14:30:22 -0000"},"content":"Given how the elfSection() is used the sub-expression\n (idx * eHdr->e_shentsize)\nit has effectively two (16 bits, unsigned) operands.\nThe sub-expression is promoted to type int (32 bits, signed) for\nmultiplication and then added to eHdr->e_shoff, which is uint32_t\non 32-bit platforms and uint64_t on 64-bit platforms. Since eHdr->e_shoff\nis unsigned, the integer conversion rules dictates that the other signed\noperand(i.e. the resultant of aforementioned sub-expression) will be\nconverted to unsigned type too. This causes sign-extension for both of\nthe above operands to match eHdr->e_shoff's type and should be avoided.\n\nThe solution is to explicitly cast one of the operands of the\nsub-expression with unsigned int type. Hence, the other operand will be\ninteger promoted and the resultant will also be of unsigned int type,\nnot requiring to bother about a sign-extension.\n\nReported-by: Coverity CID=280008\nReported-by: Coverity CID=280009\nReported-by: Coverity CID=280010\nSigned-off-by: Umang Jain \nReviewed-by: Kieran Bingham \n---\n src/libcamera/ipa_module.cpp | 3 ++-\n 1 file changed, 2 insertions(+), 1 deletion(-)","diff":"diff --git a/src/libcamera/ipa_module.cpp b/src/libcamera/ipa_module.cpp\nindex 60aaa34..72e357e 100644\n--- a/src/libcamera/ipa_module.cpp\n+++ b/src/libcamera/ipa_module.cpp\n@@ -93,7 +93,8 @@ ElfW(Shdr) *elfSection(Span elf, ElfW(Ehdr) *eHdr, ElfW(Half) idx)\n \tif (idx >= eHdr->e_shnum)\n \t\treturn nullptr;\n \n-\toff_t offset = eHdr->e_shoff + idx * eHdr->e_shentsize;\n+\toff_t offset = eHdr->e_shoff + idx *\n+\t\t\t\t static_cast(eHdr->e_shentsize);\n \treturn elfPointer(elf, offset);\n }\n \n","prefixes":["libcamera-devel","v3","2/2"]}