diff mbox series

[bpf-next,v1,13/13] selftests/bpf: Add dynptr helper tests

Message ID 20221018135920.726360-14-memxor@gmail.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series Fixes for dynptr | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 11 maintainers not CCed: sdf@google.com john.fastabend@gmail.com yhs@fb.com haoluo@google.com linux-kselftest@vger.kernel.org jolsa@kernel.org kpsingh@kernel.org song@kernel.org shuah@kernel.org mykolal@fb.com martin.lau@linux.dev
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 75 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR fail PR summary
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bpf/vmtest-bpf-next-VM_Test-7 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 fail Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 fail Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_verifier on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-10 fail Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-11 fail Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_verifier on s390x with gcc
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bpf/vmtest-bpf-next-VM_Test-9 fail Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-12 fail Logs for test_progs_no_alu32 on s390x with gcc

Commit Message

Kumar Kartikeya Dwivedi Oct. 18, 2022, 1:59 p.m. UTC 
Test that MEM_UNINIT doesn't allow writing dynptr stack slots. Next,
also add a test triggering the memmove case for dynptr_read and
dynptr_write.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 .../testing/selftests/bpf/prog_tests/dynptr.c |  3 ++
 .../testing/selftests/bpf/progs/dynptr_fail.c | 35 +++++++++++++++++++
 .../selftests/bpf/progs/dynptr_success.c      | 20 +++++++++++
 3 files changed, 58 insertions(+)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/dynptr.c b/tools/testing/selftests/bpf/prog_tests/dynptr.c
index 947126d217bd..20910598a0a6 100644
--- a/tools/testing/selftests/bpf/prog_tests/dynptr.c
+++ b/tools/testing/selftests/bpf/prog_tests/dynptr.c
@@ -42,11 +42,14 @@  static struct {
 	{"release_twice_callback", "arg 1 is an unacquired reference"},
 	{"dynptr_from_mem_invalid_api",
 		"Unsupported reg type fp for bpf_dynptr_from_mem data"},
+	{"dynptr_read_into_slot", "potential write to dynptr at off=-16"},
+	{"uninit_write_into_slot", "potential write to dynptr at off=-16"},
 
 	/* success cases */
 	{"test_read_write", NULL},
 	{"test_data_slice", NULL},
 	{"test_ringbuf", NULL},
+	{"test_overlap", NULL},
 };
 
 static void verify_fail(const char *prog_name, const char *expected_err_msg)
diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c
index b0f08ff024fb..43a0ed3736a9 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_fail.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c
@@ -622,3 +622,38 @@  int dynptr_from_mem_invalid_api(void *ctx)
 
 	return 0;
 }
+
+/* Reject writes to dynptr slot from bpf_dynptr_read */
+SEC("?raw_tp")
+int dynptr_read_into_slot(void *ctx)
+{
+	union {
+		struct {
+			char _pad[48];
+			struct bpf_dynptr ptr;
+		};
+		char buf[64];
+	} data;
+
+	bpf_ringbuf_reserve_dynptr(&ringbuf, 64, 0, &data.ptr);
+	/* this should fail */
+	bpf_dynptr_read(data.buf, sizeof(data.buf), &data.ptr, 0, 0);
+
+	return 0;
+}
+
+/* Reject writes to dynptr slot for uninit arg */
+SEC("?raw_tp")
+int uninit_write_into_slot(void *ctx)
+{
+	struct {
+		char buf[64];
+		struct bpf_dynptr ptr;
+	} data;
+
+	bpf_ringbuf_reserve_dynptr(&ringbuf, 80, 0, &data.ptr);
+	/* this should fail */
+	bpf_get_current_comm(data.buf, 80);
+
+	return 0;
+}
diff --git a/tools/testing/selftests/bpf/progs/dynptr_success.c b/tools/testing/selftests/bpf/progs/dynptr_success.c
index a3a6103c8569..401e924b15a0 100644
--- a/tools/testing/selftests/bpf/progs/dynptr_success.c
+++ b/tools/testing/selftests/bpf/progs/dynptr_success.c
@@ -162,3 +162,23 @@  int test_ringbuf(void *ctx)
 	bpf_ringbuf_discard_dynptr(&ptr, 0);
 	return 0;
 }
+
+SEC("tp/syscalls/sys_enter_nanosleep")
+int test_overlap(void *ctx)
+{
+	struct bpf_dynptr ptr;
+	void *p;
+
+	if (bpf_get_current_pid_tgid() >> 32 != pid)
+		return 0;
+	bpf_ringbuf_reserve_dynptr(&ringbuf, 16, 0, &ptr);
+	p = bpf_dynptr_data(&ptr, 0, 16);
+	if (!p) {
+		err = 1;
+		goto done;
+	}
+	bpf_dynptr_read(p + 1, 8, &ptr, 0, 0);
+done:
+	bpf_ringbuf_discard_dynptr(&ptr, 0);
+	return 0;
+}