Backport grpc uninitialized fix (#659)

grafana · Mar 1, 2024 · 636e7a0 · 636e7a0
1 parent 9cd9845
commit 636e7a0
Show file tree

Hide file tree

Showing 10 changed files with 12 additions and 1 deletion.
diff --git a/bpf/go_grpc.c b/bpf/go_grpc.c
@@ -178,8 +178,13 @@ int uprobe_server_handleStream_return(struct pt_regs *ctx) {
     // Read the embedded object ptr
     bpf_probe_read(&st_ptr, sizeof(st_ptr), (void *)(stream_ptr + grpc_stream_st_ptr_pos + sizeof(void *)));
 
-    if (st_ptr) {
+    trace->host_len = 0;
+    trace->remote_addr_len = 0;
+    trace->host_port = 0;
+    __builtin_memset(trace->host, 0, sizeof(trace->host));    
+    __builtin_memset(trace->remote_addr, 0, sizeof(trace->remote_addr));
 
+    if (st_ptr) {        
         void *remote_addr = 0;
         void *local_addr = 0;
 

diff --git a/pkg/internal/ebpf/common/spanner.go b/pkg/internal/ebpf/common/spanner.go
@@ -132,6 +132,12 @@ func extractHostPort(b []uint8) (string, int) {
 }
 
 func extractIP(b []uint8, size int) string {
+	// Temporary fix to avoid crashes if the data is not correct.
+	// We saw issues with peer location changes in grpc 1.60
+	if size < 0 || size > 4096 {
+		return ""
+	}
+
 	if size > len(b) {
 		size = len(b)
 	}

diff --git a/pkg/internal/ebpf/grpc/bpf_bpfel_arm64.o b/pkg/internal/ebpf/grpc/bpf_bpfel_arm64.o
diff --git a/pkg/internal/ebpf/grpc/bpf_bpfel_x86.o b/pkg/internal/ebpf/grpc/bpf_bpfel_x86.o
diff --git a/pkg/internal/ebpf/grpc/bpf_debug_bpfel_arm64.o b/pkg/internal/ebpf/grpc/bpf_debug_bpfel_arm64.o
diff --git a/pkg/internal/ebpf/grpc/bpf_debug_bpfel_x86.o b/pkg/internal/ebpf/grpc/bpf_debug_bpfel_x86.o
diff --git a/pkg/internal/ebpf/grpc/bpf_tp_bpfel_arm64.o b/pkg/internal/ebpf/grpc/bpf_tp_bpfel_arm64.o
diff --git a/pkg/internal/ebpf/grpc/bpf_tp_bpfel_x86.o b/pkg/internal/ebpf/grpc/bpf_tp_bpfel_x86.o
diff --git a/pkg/internal/ebpf/grpc/bpf_tp_debug_bpfel_arm64.o b/pkg/internal/ebpf/grpc/bpf_tp_debug_bpfel_arm64.o
diff --git a/pkg/internal/ebpf/grpc/bpf_tp_debug_bpfel_x86.o b/pkg/internal/ebpf/grpc/bpf_tp_debug_bpfel_x86.o