From nobody Tue Mar 19 00:01:54 2024 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4TzBjG3zx3z5FHr6; Tue, 19 Mar 2024 00:01:54 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4TzBjG3Zk0z4k5W; Tue, 19 Mar 2024 00:01:54 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1710806514; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=aGamEHO+dRyjPZYSM5tO7Nvz9KTmqxZVdJbhOc0mgCI=; b=KTZUHblkSDltKl2IinnhihI6Qlw7ZjGQ/jvMTOq/VpGliizQi7hMKFRNhDs43V7yZB2pNd OK5nGWP7dHPdC0xJCO7gGO3cKBgo028VsqLV4CCP14aNbhoqHFwyTBWpqpAT2vcwvEPUqU 8BRbJO6SzxInvqJnQQQHKjoQeA8P7bQy3CVbISJrloH1tfkSlkT2pNHgdtsteu8nC++hmD 3Lsf7vhry8u28gdaSjUGAE9K0fFjgwEdJXbLohsv9pOq5ek6syRRKsfiNLuQU0Q2tY8Kj9 XjJ9xnY8HrfVoGHbDdmvO+XfrPaf6mNlvZ6dPRkhU+TCVosAcRac0DXuV+/vGA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1710806514; a=rsa-sha256; cv=none; b=Ycwz0fzGQ3rMjMsuyIe9B+AdZJCXnNSmfEcPU/73V6BTIPgLGeu0erfkt69HkB8I0jvXsY GXbkw5pLdk7iWnIFTrUl5z5Gqn5YxDb/537T2k2xDwBin1/ZRgFVkdnX9BiM2Wym6FN+7Z rzjZvCTu4FPDAoJoYSS9cn/e8kMDbmTq8yFeamgYcCgQ+fpAIlmZnDdG4tVUnt0nIRjquw tan21CDa9fq/J3v4ScCABfRGfHDZR0ibWsxU/cEGuRsof71U1XuwQHRMYv6L98M6t3cri6 BVZIoIRmmb9US6e97ObPaCTUhEqpIQmJJO1sBL1q2TdaBjP06RQzKqbjOe/Tbg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1710806514; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=aGamEHO+dRyjPZYSM5tO7Nvz9KTmqxZVdJbhOc0mgCI=; b=t4m4hU+G9apZslR6UEkKFfnlaiI0wsJtRHmC2VcVuFD3fCd5EV1w5vnoSqq61jDA66yK5b +2IebAerqzMfvReMtfX2ZOSSEHWrZFwiwiJdb8akArWzZQVowE1ncUaHwKB8t5kqx+tper 4yNRUr12PBQiLYMLqWY/hRfzzEsqkw9U+XHbmpTVHCE7LRe3cLlqPfYUhVlyfOWNk5uHYM YF4OKlzEsLdQG7Q9Sp13Hhes1njZ/1k+uQ4vSCSS93Ejbmx0VNkZdJs/1538tto3e1ieWe iYozi3iRW/ovvJSYRI5exBUoW4WwJmQb/w84UMruqtzMKkJvaIPP+xuOO26jLQ== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4TzBjG2tFTzl50; Tue, 19 Mar 2024 00:01:54 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.17.1/8.17.1) with ESMTP id 42J01s3u030092; Tue, 19 Mar 2024 00:01:54 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.17.1/8.17.1/Submit) id 42J01sAG030089; Tue, 19 Mar 2024 00:01:54 GMT (envelope-from git) Date: Tue, 19 Mar 2024 00:01:54 GMT Message-Id: <202403190001.42J01sAG030089@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: John Baldwin Subject: git: 785600d0fb13 - main - kldxref: Properly handle reading strings near the end of an ELF file List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: jhb X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 785600d0fb13d6f0b4595bf4dbbc048113dda71d Auto-Submitted: auto-generated The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=785600d0fb13d6f0b4595bf4dbbc048113dda71d commit 785600d0fb13d6f0b4595bf4dbbc048113dda71d Author: John Baldwin AuthorDate: 2024-03-19 00:01:23 +0000 Commit: John Baldwin CommitDate: 2024-03-19 00:01:23 +0000 kldxref: Properly handle reading strings near the end of an ELF file If a string is at or near the end of an input file and the amount of remaining data in the file is smaller than the maximum string size, the pread(2) system call would return a short read which is treated as an error. Instead, add a new helper function for reading a string which permits short reads so long as the data read from the file contains a terminated string. Reported by: jrtc27 Reviewed by: jrtc27 Sponsored by: University of Cambridge, Google, Inc. Differential Revision: https://reviews.freebsd.org/D44419 --- usr.sbin/kldxref/ef.c | 9 +-------- usr.sbin/kldxref/ef.h | 4 ++++ usr.sbin/kldxref/ef_obj.c | 9 +-------- usr.sbin/kldxref/elf.c | 18 ++++++++++++++++++ 4 files changed, 24 insertions(+), 16 deletions(-) diff --git a/usr.sbin/kldxref/ef.c b/usr.sbin/kldxref/ef.c index 1ef27f2bc54a..77ddada946f2 100644 --- a/usr.sbin/kldxref/ef.c +++ b/usr.sbin/kldxref/ef.c @@ -549,7 +549,6 @@ static int ef_seg_read_string(elf_file_t ef, GElf_Addr address, size_t len, char *dest) { GElf_Off ofs; - int error; ofs = ef_get_offset(ef, address); if (ofs == 0) { @@ -559,13 +558,7 @@ ef_seg_read_string(elf_file_t ef, GElf_Addr address, size_t len, char *dest) return (EFAULT); } - error = elf_read_raw_data(ef->ef_efile, ofs, dest, len); - if (error != 0) - return (error); - if (strnlen(dest, len) == len) - return (EFAULT); - - return (0); + return (elf_read_raw_string(ef->ef_efile, ofs, dest, len)); } int diff --git a/usr.sbin/kldxref/ef.h b/usr.sbin/kldxref/ef.h index 25dc5216b169..9d3dc1b1b435 100644 --- a/usr.sbin/kldxref/ef.h +++ b/usr.sbin/kldxref/ef.h @@ -189,6 +189,10 @@ int elf_read_raw_data(struct elf_file *efile, off_t offset, void *dst, int elf_read_raw_data_alloc(struct elf_file *efile, off_t offset, size_t len, void **out); +/* Reads a single string at the given offset from an ELF file. */ +int elf_read_raw_string(struct elf_file *efile, off_t offset, char *dst, + size_t len); + /* * Read relocated data from an ELF file and return it in a * dynamically-allocated buffer. Note that no translation diff --git a/usr.sbin/kldxref/ef_obj.c b/usr.sbin/kldxref/ef_obj.c index 1274a14c10af..ac83137cd394 100644 --- a/usr.sbin/kldxref/ef_obj.c +++ b/usr.sbin/kldxref/ef_obj.c @@ -248,7 +248,6 @@ static int ef_obj_seg_read_string(elf_file_t ef, GElf_Addr address, size_t len, char *dest) { GElf_Off ofs; - int error; ofs = ef_obj_get_offset(ef, address); if (ofs == 0) { @@ -258,13 +257,7 @@ ef_obj_seg_read_string(elf_file_t ef, GElf_Addr address, size_t len, char *dest) return (EFAULT); } - error = elf_read_raw_data(ef->ef_efile, ofs, dest, len); - if (error != 0) - return (error); - if (strnlen(dest, len) == len) - return (EFAULT); - - return (0); + return (elf_read_raw_string(ef->ef_efile, ofs, dest, len)); } int diff --git a/usr.sbin/kldxref/elf.c b/usr.sbin/kldxref/elf.c index e5fe90169d2c..a93cf996ccc7 100644 --- a/usr.sbin/kldxref/elf.c +++ b/usr.sbin/kldxref/elf.c @@ -197,6 +197,24 @@ elf_read_raw_data_alloc(struct elf_file *efile, off_t offset, size_t len, return (0); } +int +elf_read_raw_string(struct elf_file *efile, off_t offset, char *dst, size_t len) +{ + ssize_t nread; + + nread = pread(efile->ef_fd, dst, len, offset); + if (nread == -1) + return (errno); + if (nread == 0) + return (EIO); + + /* A short read is ok so long as the data contains a terminator. */ + if (strnlen(dst, nread) == nread) + return (EFAULT); + + return (0); +} + int elf_read_data(struct elf_file *efile, Elf_Type type, off_t offset, size_t len, void **out)