From: John Fastabend <john.fastabend@gmail.com>
To: ecree@solarflare.com, yhs@fb.com, alexei.starovoitov@gmail.com,
daniel@iogearbox.net
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, john.fastabend@gmail.com
Subject: [bpf-next PATCH 06/10] bpf: test_progs, add test to catch retval refine error handling
Date: Tue, 24 Mar 2020 10:39:36 -0700 [thread overview]
Message-ID: <158507157618.15666.3720338936586861726.stgit@john-Precision-5820-Tower> (raw)
In-Reply-To: <158507130343.15666.8018068546764556975.stgit@john-Precision-5820-Tower>
Before this series the verifier would clamp return bounds of
bpf_get_stack() to [0, X] and this led the verifier to believe
that a JMP_JSLT 0 would be false and so would prune that path.
The result is anything hidden behind that JSLT would be unverified.
Add a test to catch this case by hiding an goto pc-1 behind the
check which will cause an infinite loop if not rejected.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
.../selftests/bpf/prog_tests/get_stack_raw_tp.c | 5 ++++
.../selftests/bpf/progs/test_get_stack_rawtp_err.c | 26 ++++++++++++++++++++
2 files changed, 31 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/test_get_stack_rawtp_err.c
diff --git a/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c b/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
index eba9a97..9257222 100644
--- a/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
+++ b/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
@@ -82,6 +82,7 @@ static void get_stack_print_output(void *ctx, int cpu, void *data, __u32 size)
void test_get_stack_raw_tp(void)
{
const char *file = "./test_get_stack_rawtp.o";
+ const char *file_err = "./test_get_stack_rawtp_err.o";
const char *prog_name = "raw_tracepoint/sys_enter";
int i, err, prog_fd, exp_cnt = MAX_CNT_RAWTP;
struct perf_buffer_opts pb_opts = {};
@@ -93,6 +94,10 @@ void test_get_stack_raw_tp(void)
struct bpf_map *map;
cpu_set_t cpu_set;
+ err = bpf_prog_load(file_err, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
+ if (CHECK(err >= 0, "prog_load raw tp", "err %d errno %d\n", err, errno))
+ return;
+
err = bpf_prog_load(file, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd);
if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno))
return;
diff --git a/tools/testing/selftests/bpf/progs/test_get_stack_rawtp_err.c b/tools/testing/selftests/bpf/progs/test_get_stack_rawtp_err.c
new file mode 100644
index 0000000..8941a41
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_get_stack_rawtp_err.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define MAX_STACK_RAWTP 10
+
+SEC("raw_tracepoint/sys_enter")
+int bpf_prog2(void *ctx)
+{
+ __u64 stack[MAX_STACK_RAWTP];
+ int error;
+
+ /* set all the flags which should return -EINVAL */
+ error = bpf_get_stack(ctx, stack, 0, -1);
+ if (error < 0)
+ goto loop;
+
+ return error;
+loop:
+ while (1) {
+ error++;
+ }
+}
+
+char _license[] SEC("license") = "GPL";
next prev parent reply other threads:[~2020-03-24 17:39 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 17:37 [bpf-next PATCH 00/10] ALU32 bounds tracking support John Fastabend
2020-03-24 17:37 ` [bpf-next PATCH 01/10] bpf: verifier, do_refine_retval_range may clamp umin to 0 incorrectly John Fastabend
2020-03-24 17:38 ` [bpf-next PATCH 02/10] bpf: verifer, refactor adjust_scalar_min_max_vals John Fastabend
2020-03-26 6:10 ` Alexei Starovoitov
2020-03-24 17:38 ` [bpf-next PATCH 03/10] bpf: verifer, adjust_scalar_min_max_vals to always call update_reg_bounds() John Fastabend
2020-03-24 17:38 ` [bpf-next PATCH 04/10] bpf: verifier, do explicit ALU32 bounds tracking John Fastabend
2020-03-26 6:20 ` Alexei Starovoitov
2020-03-26 15:18 ` John Fastabend
2020-03-24 17:39 ` [bpf-next PATCH 05/10] bpf: verifier, return value is an int in do_refine_retval_range John Fastabend
2020-03-26 6:23 ` Alexei Starovoitov
2020-03-26 15:52 ` John Fastabend
2020-03-24 17:39 ` John Fastabend [this message]
2020-03-24 17:39 ` [bpf-next PATCH 07/10] bpf: test_verifier, bpf_get_stack return value add <0 John Fastabend
2020-03-26 6:33 ` Alexei Starovoitov
2020-03-26 15:48 ` John Fastabend
2020-03-24 17:40 ` [bpf-next PATCH 08/10] bpf: test_verifier, #70 error message updates for 32-bit right shift John Fastabend
2020-03-24 17:40 ` [bpf-next PATCH 09/10] bpf: test_verifier, #65 error message updates for trunc of boundary-cross John Fastabend
2020-03-24 17:40 ` [bpf-next PATCH 10/10] bpf: test_verifier, add alu32 bounds tracking tests John Fastabend
2020-03-26 6:34 ` Alexei Starovoitov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=158507157618.15666.3720338936586861726.stgit@john-Precision-5820-Tower \
--to=john.fastabend@gmail.com \
--cc=alexei.starovoitov@gmail.com \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=ecree@solarflare.com \
--cc=netdev@vger.kernel.org \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).