From: Ihor Solodrai <ihor.solodrai@linux.dev>
To: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Eduard Zingerman <eddyz87@gmail.com>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com
Subject: [PATCH bpf v1 4/7] selftests/bpf: Replace strncpy() with strscpy()
Date: Fri, 20 Feb 2026 10:20:08 -0800 [thread overview]
Message-ID: <20260220182011.802116-5-ihor.solodrai@linux.dev> (raw)
In-Reply-To: <20260220182011.802116-1-ihor.solodrai@linux.dev>
strncpy() does not guarantee NUL-termination and is considered
deprecated [1]. Replace strncpy() calls with strscpy().
[1] https://docs.kernel.org/process/deprecated.html#strncpy-on-nul-terminated-strings
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
---
tools/testing/selftests/bpf/network_helpers.c | 3 +--
tools/testing/selftests/bpf/prog_tests/align.c | 2 +-
tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 3 +--
tools/testing/selftests/bpf/prog_tests/flow_dissector.c | 4 ++--
tools/testing/selftests/bpf/prog_tests/queue_stack_map.c | 4 ++--
tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c | 2 +-
tools/testing/selftests/bpf/prog_tests/task_local_data.h | 2 +-
tools/testing/selftests/bpf/prog_tests/tc_redirect.c | 2 +-
tools/testing/selftests/bpf/test_progs.c | 2 +-
tools/testing/selftests/bpf/xdp_hw_metadata.c | 4 ++--
10 files changed, 13 insertions(+), 15 deletions(-)
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 5374b7e16d53..e169c6ece524 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -581,8 +581,7 @@ int open_tuntap(const char *dev_name, bool need_mac)
return -1;
ifr.ifr_flags = IFF_NO_PI | (need_mac ? IFF_TAP : IFF_TUN);
- strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
- ifr.ifr_name[IFNAMSIZ - 1] = '\0';
+ strscpy(ifr.ifr_name, dev_name, sizeof(ifr.ifr_name));
err = ioctl(fd, TUNSETIFF, &ifr);
if (!ASSERT_OK(err, "ioctl(TUNSETIFF)")) {
diff --git a/tools/testing/selftests/bpf/prog_tests/align.c b/tools/testing/selftests/bpf/prog_tests/align.c
index 24c509ce4e5b..7b6e530a586c 100644
--- a/tools/testing/selftests/bpf/prog_tests/align.c
+++ b/tools/testing/selftests/bpf/prog_tests/align.c
@@ -633,7 +633,7 @@ static int do_test_single(struct bpf_align_test *test)
} else {
ret = 0;
/* We make a local copy so that we can strtok() it */
- strncpy(bpf_vlog_copy, bpf_vlog, sizeof(bpf_vlog_copy));
+ strscpy(bpf_vlog_copy, bpf_vlog, sizeof(bpf_vlog_copy));
start = strstr(bpf_vlog_copy, main_pass_start);
if (!start) {
ret = 1;
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
index 5225d69bf79b..c69080ca14f5 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
@@ -346,8 +346,7 @@ static void test_task_sleepable(void)
close(finish_pipe[1]);
test_data = malloc(sizeof(char) * 10);
- strncpy(test_data, "test_data", 10);
- test_data[9] = '\0';
+ strscpy(test_data, "test_data", 10);
test_data_long = malloc(sizeof(char) * 5000);
for (int i = 0; i < 5000; ++i) {
diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
index 08bae13248c4..22dbd13cf592 100644
--- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
@@ -570,7 +570,7 @@ static int create_tap(const char *ifname)
};
int fd, ret;
- strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+ strscpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
fd = open("/dev/net/tun", O_RDWR);
if (fd < 0)
@@ -599,7 +599,7 @@ static int ifup(const char *ifname)
struct ifreq ifr = {};
int sk, ret;
- strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+ strscpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
sk = socket(PF_INET, SOCK_DGRAM, 0);
if (sk < 0)
diff --git a/tools/testing/selftests/bpf/prog_tests/queue_stack_map.c b/tools/testing/selftests/bpf/prog_tests/queue_stack_map.c
index a043af9cd6d9..a3c6acc33d5d 100644
--- a/tools/testing/selftests/bpf/prog_tests/queue_stack_map.c
+++ b/tools/testing/selftests/bpf/prog_tests/queue_stack_map.c
@@ -28,9 +28,9 @@ static void test_queue_stack_map_by_type(int type)
vals[i] = rand();
if (type == QUEUE)
- strncpy(file, "./test_queue_map.bpf.o", sizeof(file));
+ strscpy(file, "./test_queue_map.bpf.o", sizeof(file));
else if (type == STACK)
- strncpy(file, "./test_stack_map.bpf.o", sizeof(file));
+ strscpy(file, "./test_stack_map.bpf.o", sizeof(file));
else
return;
diff --git a/tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c b/tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c
index 3eefdfed1db9..74f6d7404d1b 100644
--- a/tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c
+++ b/tools/testing/selftests/bpf/prog_tests/skc_to_unix_sock.c
@@ -34,7 +34,7 @@ void test_skc_to_unix_sock(void)
memset(&sockaddr, 0, sizeof(sockaddr));
sockaddr.sun_family = AF_UNIX;
- strncpy(sockaddr.sun_path, sock_path, strlen(sock_path));
+ strscpy(sockaddr.sun_path, sock_path, sizeof(sockaddr.sun_path));
sockaddr.sun_path[0] = '\0';
err = bind(sockfd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
diff --git a/tools/testing/selftests/bpf/prog_tests/task_local_data.h b/tools/testing/selftests/bpf/prog_tests/task_local_data.h
index 0f86b9275cf9..26e6218a2dd6 100644
--- a/tools/testing/selftests/bpf/prog_tests/task_local_data.h
+++ b/tools/testing/selftests/bpf/prog_tests/task_local_data.h
@@ -262,7 +262,7 @@ static tld_key_t __tld_create_key(const char *name, size_t size, bool dyn_data)
if (!atomic_compare_exchange_strong(&tld_meta_p->cnt, &cnt, cnt + 1))
goto retry;
- strncpy(tld_meta_p->metadata[i].name, name, TLD_NAME_LEN);
+ strscpy(tld_meta_p->metadata[i].name, name, TLD_NAME_LEN);
atomic_store(&tld_meta_p->metadata[i].size, size);
return (tld_key_t){(__s16)off};
}
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c
index 76d72a59365e..bd0010e5364f 100644
--- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c
@@ -1095,7 +1095,7 @@ static int tun_open(char *name)
ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
if (*name)
- strncpy(ifr.ifr_name, name, IFNAMSIZ);
+ strscpy(ifr.ifr_name, name, IFNAMSIZ);
err = ioctl(fd, TUNSETIFF, &ifr);
if (!ASSERT_OK(err, "ioctl TUNSETIFF"))
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 02a85dda30e6..d1418ec1f351 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1799,7 +1799,7 @@ static int worker_main_send_subtests(int sock, struct test_state *state)
msg.subtest_done.num = i;
- strncpy(msg.subtest_done.name, subtest_state->name, MAX_SUBTEST_NAME);
+ strscpy(msg.subtest_done.name, subtest_state->name, MAX_SUBTEST_NAME);
msg.subtest_done.error_cnt = subtest_state->error_cnt;
msg.subtest_done.skipped = subtest_state->skipped;
diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index 3d8de0d4c96a..1de1bcdb2c9a 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -550,7 +550,7 @@ static int rxq_num(const char *ifname)
struct ifreq ifr = {
.ifr_data = (void *)&ch,
};
- strncpy(ifr.ifr_name, ifname, IF_NAMESIZE - 1);
+ strscpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
int fd, ret;
fd = socket(AF_UNIX, SOCK_DGRAM, 0);
@@ -571,7 +571,7 @@ static void hwtstamp_ioctl(int op, const char *ifname, struct hwtstamp_config *c
struct ifreq ifr = {
.ifr_data = (void *)cfg,
};
- strncpy(ifr.ifr_name, ifname, IF_NAMESIZE - 1);
+ strscpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
int fd, ret;
fd = socket(AF_UNIX, SOCK_DGRAM, 0);
--
2.53.0
next prev parent reply other threads:[~2026-02-20 18:20 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-20 18:20 [PATCH bpf v1 0/7] selftests/bpf: Add and use strscpy() Ihor Solodrai
2026-02-20 18:20 ` [PATCH bpf v1 1/7] selftests/bpf: Add simple strscpy() implementation Ihor Solodrai
2026-02-20 18:20 ` [PATCH bpf v1 2/7] selftests/bpf: Add strscpy_cat() Ihor Solodrai
2026-02-20 23:04 ` Alexei Starovoitov
2026-02-20 18:20 ` [PATCH bpf v1 3/7] selftests/bpf: Replace strcpy() calls with strscpy() Ihor Solodrai
2026-02-20 18:20 ` Ihor Solodrai [this message]
2026-02-20 18:20 ` [PATCH bpf v1 5/7] selftests/bpf: Use strscpy_cat() in the test_loader Ihor Solodrai
2026-02-20 18:20 ` [PATCH bpf v1 6/7] selftests/bpf: Use strscpy in bpftool_helpers.c Ihor Solodrai
2026-02-20 18:20 ` [PATCH bpf v1 7/7] selftests/bpf: Use memcpy() for bounded non-NULL-terminated copies Ihor Solodrai
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