From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7DBE2364049; Sat, 12 Sep 2026 08:22:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789201330; cv=none; b=pJoL1dQ9I7S9jkO0zj5U8GavrR1sZQVEK/P7YgtMewarmGOIUjnVfxQcT2gv5eb4pda1kDXuL1S/NtT7h83W9mC/sa6qbYLeGQ3cC++/1gJkI6DKs9DIOUU5hUY8ykKmGVUnOHaINC01El4oq2uJKfVf5GLTJqZ8lxB2Vu6CS6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789201330; c=relaxed/simple; bh=G7VZMnLuoz6rQ6AG4NV5ZSJE/qncbKG3sMC7D9wzFTY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IRa3/lALO3lmmu5coUVEX/MAOissJ4MV0N+5xOhv1XmJZefrEbuDJow3Y/NZMTteccPcfmP188KjOCLo38zNFYGt+Isrd7TIZrUgsA0Hw8vBR+fKoTQ2VcK6GhTrcpzkbGAM08V5Uq/sT8NuFuoX2sj7Wm88VtMA5auA8WNXg9c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NoHa1kBQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="NoHa1kBQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 824041F000FF; Sat, 12 Sep 2026 08:22:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789201329; bh=nViI678pIKKZO+7yX6RMnMNhiEGa2PssZ2QlCIlO2a4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NoHa1kBQAs+H1GiAs2ALW5jfxfYE9NNjfCUWc/JwegEoq8NsH9b30Hp9dQ1zDvti5 UUYiH0sTA2cF+4JpQfmQLnzDx1QacWRizanto7OAHUO2lr0J0/9qOOhqTnGkUtCLi/ 7IvTC9QRirgtxAqsOC31ikcnHtKPN1UgEsT5NP5E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ben Procknow , Joe Lawrence , Josh Poimboeuf , Ingo Molnar , Miroslav Benes , live-patching@vger.kernel.org, Sasha Levin Subject: [PATCH 7.2 0975/1815] objtool/klp: Normalize Module.symvers paths to module names Date: Sat, 12 Sep 2026 08:45:25 +0200 Message-ID: <20260912065711.870422699@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065648.999753832@linuxfoundation.org> References: <20260912065648.999753832@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joe Lawrence [ Upstream commit 8668bf91e0508abeb8e98b4edd89032be02228a1 ] Module.symvers contains build-tree object paths as module identifiers (e.g., "arch/x86/kvm/kvm") rather than runtime module names ("kvm"). Objtool's clone_reloc_klp() uses this field directly for exported symbols, while unexported symbols correctly go through __find_modname(). This means that exported symbol relocations may land in a .klp.rela section named with the build path rather than the module name. That is a crash waiting to happen: the kernel's livepatch loader silently skips this relocation because it doesn't match the expected klp_object name. The unresolved relocation sits in the newly activated code, crashing when executed. Normalize export->mod at Module.symvers read time using the same logic as __find_modname() (refactored into a shared normalize_modname() helper). Fixes: dd590d4d57eb ("objtool/klp: Introduce klp diff subcommand for diffing object files") Reported-by: Ben Procknow Signed-off-by: Joe Lawrence Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Reviewed-by: Miroslav Benes Cc: live-patching@vger.kernel.org Link: https://patch.msgid.link/dbe1b72931bd3c31b751fd0729613d9f2226fff6.1785727106.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin --- tools/objtool/klp-diff.c | 49 ++++++++++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 15 deletions(-) diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c index aeb99d572300c..15d37d955af0e 100644 --- a/tools/objtool/klp-diff.c +++ b/tools/objtool/klp-diff.c @@ -83,6 +83,35 @@ static char *escape_str(const char *orig) return new; } +/* + * Convert a build-tree object path to a runtime module name: strip + * directory components, replace '-' with '_', and remove file + * extensions. Examples: + * + * "arch/x86/kvm/kvm" -> "kvm" + * "arch/x86/kvm/kvm-intel" -> "kvm_intel". + * + * Used by read_exports() to normalize Module.symvers entries and by + * __find_modname() as a fallback when .modinfo lacks a "name=" tag. + */ +static char *normalize_modname(char *name) +{ + char *slash = strrchr(name, '/'); + + if (slash) + name = slash + 1; + + for (char *c = name; *c; c++) { + if (*c == '-') + *c = '_'; + else if (*c == '.') { + *c = '\0'; + break; + } + } + return name; +} + static int read_exports(void) { const char *symvers = "Module.symvers"; @@ -150,6 +179,9 @@ static int read_exports(void) return -1; } + if (strcmp(export->mod, "vmlinux")) + export->mod = normalize_modname(export->mod); + export->sym = strdup(sym); if (!export->sym) { ERROR_GLIBC("strdup"); @@ -1140,7 +1172,7 @@ static struct export *find_export(struct symbol *sym) static const char *__find_modname(struct elfs *e) { struct section *sec; - char *name, *slash; + char *name; sec = find_section_by_name(e->orig, ".modinfo"); if (!sec) { @@ -1158,20 +1190,7 @@ static const char *__find_modname(struct elfs *e) return NULL; } - slash = strrchr(name, '/'); - if (slash) - name = slash + 1; - - for (char *c = name; *c; c++) { - if (*c == '-') - *c = '_'; - else if (*c == '.') { - *c = '\0'; - break; - } - } - - return name; + return normalize_modname(name); } /* Get the object's module name as defined by the kernel (and klp_object) */ -- 2.53.0