While at it, also try breaking bpf_sock_from_file, since it doesn't
check its argument for NULL in the first place. With our fix, both
shouldn't crash.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/d_path_crash.c | 19 ++++++++++++++
.../selftests/bpf/progs/d_path_crash.c | 26 +++++++++++++++++++
2 files changed, 45 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/d_path_crash.c
create mode 100644 tools/testing/selftests/bpf/progs/d_path_crash.c
diff --git a/tools/testing/selftests/bpf/prog_tests/d_path_crash.c b/tools/testing/selftests/bpf/prog_tests/d_path_crash.c
new file mode 100644
index 000000000000..b1ee705d2108
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/d_path_crash.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "d_path_crash.skel.h"
+
+void test_d_path_crash(void)
+{
+ struct d_path_crash *skel;
+
+ skel = d_path_crash__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "d_path_crash__open_and_load"))
+ return;
+ skel->bss->pid = getpid();
+ ASSERT_OK(d_path_crash__attach(skel), "d_path__attach");
+ close(open("/dev/null", O_RDONLY));
+ d_path_crash__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/d_path_crash.c b/tools/testing/selftests/bpf/progs/d_path_crash.c
new file mode 100644
index 000000000000..a4b1a8b200f3
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/d_path_crash.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+int pid = 0;
+
+SEC("lsm/file_open")
+int BPF_PROG(lsm_file_open, struct file *file)
+{
+ struct task_struct *current = bpf_get_current_task_btf();
+ unsigned long *val, l;
+ char buf[64] = {};
+ struct file *f;
+
+ if (current->tgid != pid)
+ return 0;
+
+ f = current->files->fd_array[63];
+ bpf_d_path(&f->f_path, buf, sizeof(buf));
+ /* If we survived, let's try our luck here */
+ bpf_sock_from_file(f);
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.35.1
