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-rw-r--r--kernel/trace/bpf_trace.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 9a050e36dc6c..1f4b07da327a 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -900,13 +900,23 @@ static const struct bpf_func_proto bpf_send_signal_thread_proto = {
BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
{
+ struct path copy;
long len;
char *p;
if (!sz)
return 0;
- p = d_path(path, buf, sz);
+ /*
+ * The path pointer is verified as trusted and safe to use,
+ * but let's double check it's valid anyway to workaround
+ * potentially broken verifier.
+ */
+ len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
+ if (len < 0)
+ return len;
+
+ p = d_path(&copy, buf, sz);
if (IS_ERR(p)) {
len = PTR_ERR(p);
} else {