linux-kernel - [PATCH AUTOSEL 5.19 01/73] libbpf: Do not require executable permission for shared libraries

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]

Date:   Sun,  9 Oct 2022 18:13:39 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Hengqi Chen <hengqi.chen@...il.com>, Goro Fuji <goro@...tly.com>,
        Andrii Nakryiko <andrii@...nel.org>,
        Sasha Levin <sashal@...nel.org>, ast@...nel.org,
        daniel@...earbox.net, bpf@...r.kernel.org
Subject: [PATCH AUTOSEL 5.19 01/73] libbpf: Do not require executable permission for shared libraries

From: Hengqi Chen <hengqi.chen@...il.com>

[ Upstream commit 9e32084ef1c33a87a736d6ce3fcb95b60dac9aa1 ]

Currently, resolve_full_path() requires executable permission for both
programs and shared libraries. This causes failures on distos like Debian
since the shared libraries are not installed executable and Linux is not
requiring shared libraries to have executable permissions. Let's remove
executable permission check for shared libraries.

Reported-by: Goro Fuji <goro@...tly.com>
Signed-off-by: Hengqi Chen <hengqi.chen@...il.com>
Signed-off-by: Andrii Nakryiko <andrii@...nel.org>
Link: https://lore.kernel.org/bpf/20220806102021.3867130-1-hengqi.chen@gmail.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 tools/lib/bpf/libbpf.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 266357b1dca1..91bfe42e5cf4 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -11206,15 +11206,17 @@ static const char *arch_specific_lib_paths(void)
 static int resolve_full_path(const char *file, char *result, size_t result_sz)
 {
 	const char *search_paths[3] = {};
-	int i;
+	int i, perm;
 
 	if (str_has_sfx(file, ".so") || strstr(file, ".so.")) {
 		search_paths[0] = getenv("LD_LIBRARY_PATH");
 		search_paths[1] = "/usr/lib64:/usr/lib";
 		search_paths[2] = arch_specific_lib_paths();
+		perm = R_OK;
 	} else {
 		search_paths[0] = getenv("PATH");
 		search_paths[1] = "/usr/bin:/usr/sbin";
+		perm = R_OK | X_OK;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(search_paths); i++) {
@@ -11233,8 +11235,8 @@ static int resolve_full_path(const char *file, char *result, size_t result_sz)
 			if (!seg_len)
 				continue;
 			snprintf(result, result_sz, "%.*s/%s", seg_len, s, file);
-			/* ensure it is an executable file/link */
-			if (access(result, R_OK | X_OK) < 0)
+			/* ensure it has required permissions */
+			if (access(result, perm) < 0)
 				continue;
 			pr_debug("resolved '%s' to '%s'\n", file, result);
 			return 0;
-- 
2.35.1