From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BE27F17CA12; Mon, 10 Mar 2025 17:51:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741629100; cv=none; b=GKeU1dIdT4msw6YC1C2bWrPZ1b6U9aBCo9M3adUhs3gRp3LFxRIzKr2UUKwW8TRvMA22VkIdLYeQU/mJSL38UuQ5y/RgFZub17Kl2UPYjNAFn7Tb9wBsq/FcVHF4C8eGrMSOMUOFTRsNTdUDnbOLGu8YJ7SxWxynwf2dj6Ogkpg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741629100; c=relaxed/simple; bh=poqhwnVyN8atMWi6dcb5hOvi/e9KHFdNcR3SXus1JNY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DMIcxohHfV4nu3GryyP3fNFZLQFsLhqKHp9fFyq/EDx7nny7I6RRWyzqH660yFo1gnNoTZ9OsJTR1DkYhpO7DsMOmJ28BpQbRY1B1Q8RfKaMRBDWexMXslwees0w4gFPA0pSN+RECRPs4qhZPefQjW+QRAzfURg9bc3ir4ohP/U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nD4HkyYF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nD4HkyYF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 484B1C4CEE5; Mon, 10 Mar 2025 17:51:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741629100; bh=poqhwnVyN8atMWi6dcb5hOvi/e9KHFdNcR3SXus1JNY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nD4HkyYFZMaUtKPt5YU+sskWXE0HswcIwy1nQAfKeim0lzrlWu2cTVlp6kkXVg7Ks ihmrlIDBKB1E1XXSgKN45j5O9UPT3TgKeJYTkUGiLkG8Ba04ttzQj6nWsTzhgeAV6g e8W+R1YX7jaEtYjqGKFESjJ9npGXwgw5IqhDF2uE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masahiro Yamada , Sasha Levin Subject: [PATCH 5.15 176/620] genksyms: fix memory leak when the same symbol is read from *.symref file Date: Mon, 10 Mar 2025 18:00:22 +0100 Message-ID: <20250310170552.571414062@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170545.553361750@linuxfoundation.org> References: <20250310170545.553361750@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masahiro Yamada [ Upstream commit be2fa44b5180a1f021efb40c55fdf63c249c3209 ] When a symbol that is already registered is read again from *.symref file, __add_symbol() removes the previous one from the hash table without freeing it. [Test Case] $ cat foo.c #include void foo(void); void foo(void) {} EXPORT_SYMBOL(foo); $ cat foo.symref foo void foo ( void ) foo void foo ( void ) When a symbol is removed from the hash table, it must be freed along with its ->name and ->defn members. However, sym->name cannot be freed because it is sometimes shared with node->string, but not always. If sym->name and node->string share the same memory, free(sym->name) could lead to a double-free bug. To resolve this issue, always assign a strdup'ed string to sym->name. Fixes: 64e6c1e12372 ("genksyms: track symbol checksum changes") Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin --- scripts/genksyms/genksyms.c | 8 ++++++-- scripts/genksyms/genksyms.h | 2 +- scripts/genksyms/parse.y | 4 ++-- 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c index de64aea6e8b4c..0c4d780fbbd83 100644 --- a/scripts/genksyms/genksyms.c +++ b/scripts/genksyms/genksyms.c @@ -274,11 +274,15 @@ static struct symbol *__add_symbol(const char *name, enum symbol_type type, break; } } + + free_list(sym->defn, NULL); + free(sym->name); + free(sym); --nsyms; } sym = xmalloc(sizeof(*sym)); - sym->name = name; + sym->name = xstrdup(name); sym->type = type; sym->defn = defn; sym->expansion_trail = NULL; @@ -485,7 +489,7 @@ static void read_reference(FILE *f) defn = def; def = read_node(f); } - subsym = add_reference_symbol(xstrdup(sym->string), sym->tag, + subsym = add_reference_symbol(sym->string, sym->tag, defn, is_extern); subsym->is_override = is_override; free_node(sym); diff --git a/scripts/genksyms/genksyms.h b/scripts/genksyms/genksyms.h index 21ed2ec2d98ca..5621533dcb8e4 100644 --- a/scripts/genksyms/genksyms.h +++ b/scripts/genksyms/genksyms.h @@ -32,7 +32,7 @@ struct string_list { struct symbol { struct symbol *hash_next; - const char *name; + char *name; enum symbol_type type; struct string_list *defn; struct symbol *expansion_trail; diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y index 840371d01bf48..689cb6bb40b65 100644 --- a/scripts/genksyms/parse.y +++ b/scripts/genksyms/parse.y @@ -482,12 +482,12 @@ enumerator_list: enumerator: IDENT { - const char *name = strdup((*$1)->string); + const char *name = (*$1)->string; add_symbol(name, SYM_ENUM_CONST, NULL, 0); } | IDENT '=' EXPRESSION_PHRASE { - const char *name = strdup((*$1)->string); + const char *name = (*$1)->string; struct string_list *expr = copy_list_range(*$3, *$2); add_symbol(name, SYM_ENUM_CONST, expr, 0); } -- 2.39.5