linux-kernel - [PATCH] module: Refine kmemleak scanned areas

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240906153856.22204-1-vdonnefort@google.com>
Date: Fri,  6 Sep 2024 16:38:56 +0100
From: Vincent Donnefort <vdonnefort@...gle.com>
To: mcgrof@...nel.org
Cc: linux-modules@...r.kernel.org, linux-kernel@...r.kernel.org, 
	kernel-team@...roid.com, Vincent Donnefort <vdonnefort@...gle.com>, Song Liu <song@...nel.org>, 
	Catalin Marinas <catalin.marinas@....com>
Subject: [PATCH] module: Refine kmemleak scanned areas

commit ac3b43283923 ("module: replace module_layout with module_memory")
introduced a set of memory regions for the module layout sharing the
same attributes but didn't update the kmemleak scanned areas which
intended to limit kmemleak scan to sections containing writable data.
This means sections such as .text and .rodata are scanned by kmemleak.

Refine the scanned areas for modules by limiting it to MOD_TEXT and
MOD_INIT_TEXT mod_mem regions.

CC: Song Liu <song@...nel.org>
CC: Catalin Marinas <catalin.marinas@....com>
Signed-off-by: Vincent Donnefort <vdonnefort@...gle.com>

diff --git a/kernel/module/debug_kmemleak.c b/kernel/module/debug_kmemleak.c
index 12a569d361e8..b4cc03842d70 100644
--- a/kernel/module/debug_kmemleak.c
+++ b/kernel/module/debug_kmemleak.c
@@ -12,19 +12,9 @@
 void kmemleak_load_module(const struct module *mod,
 			  const struct load_info *info)
 {
-	unsigned int i;
-
-	/* only scan the sections containing data */
-	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
-
-	for (i = 1; i < info->hdr->e_shnum; i++) {
-		/* Scan all writable sections that's not executable */
-		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
-		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
-		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
-			continue;
-
-		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
-				   info->sechdrs[i].sh_size, GFP_KERNEL);
+	/* only scan writable, non-executable sections */
+	for_each_mod_mem_type(type) {
+		if (type != MOD_DATA && type != MOD_INIT_DATA)
+			kmemleak_no_scan(mod->mem[type].base);
 	}
 }

base-commit: 431c1646e1f86b949fa3685efc50b660a364c2b6
-- 
2.46.0.598.g6f2099f65c-goog