[PATCH bpf-next] selftests/bpf: Bump and validate MAX_SYMS
From: Björn Töpel
Date: Thu Jul 06 2023 - 10:22:49 EST
From: Björn Töpel <bjorn@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
---
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