netdev - [PATCH bpf-next] selftests/bpf: Bump and validate MAX

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: <20230706142228.1128452-1-bjorn@kernel.org>
Date: Thu,  6 Jul 2023 16:22:28 +0200
From: Björn Töpel <bjorn@...nel.org>
To: Andrii Nakryiko <andrii@...nel.org>,
	Mykola Lysenko <mykolal@...com>,
	bpf@...r.kernel.org,
	netdev@...r.kernel.org
Cc: Björn Töpel <bjorn@...osinc.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	linux-kselftest@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH bpf-next] selftests/bpf: Bump and validate MAX_SYMS

From: Björn Töpel <bjorn@...osinc.com>

BPF tests that load /proc/kallsyms, e.g. bpf_cookie, will perform a
buffer overrun if the number of syms on the system is larger than
MAX_SYMS.

Bump the MAX_SYMS to 400000, and add a runtime check that bails out if
the maximum is reached.

Signed-off-by: Björn Töpel <bjorn@...osinc.com>
---
 tools/testing/selftests/bpf/trace_helpers.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index 9b070cdf44ac..f83d9f65c65b 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -18,7 +18,7 @@
 #define TRACEFS_PIPE	"/sys/kernel/tracing/trace_pipe"
 #define DEBUGFS_PIPE	"/sys/kernel/debug/tracing/trace_pipe"
 
-#define MAX_SYMS 300000
+#define MAX_SYMS 400000
 static struct ksym syms[MAX_SYMS];
 static int sym_cnt;
 
@@ -46,6 +46,9 @@ int load_kallsyms_refresh(void)
 			break;
 		if (!addr)
 			continue;
+		if (i >= MAX_SYMS)
+			return -EFBIG;
+
 		syms[i].addr = (long) addr;
 		syms[i].name = strdup(func);
 		i++;

base-commit: fd283ab196a867f8f65f36913e0fadd031fcb823
-- 
2.39.2