[PATCH 1/1] selftests: vsock: avoid mktemp -u for Unix socket paths

[PATCH 1/1] selftests: vsock: avoid mktemp -u for Unix socket paths

[CaoRuichuang]

The namespace tests create temporary Unix socket paths with mktemp -u and
then hand them to socat. That only prints an unused pathname and leaves
a race before the socket is created.

Create a private temporary directory with mktemp -d and place the Unix
socket inside it instead. This keeps the path unique without relying on
mktemp -u for filesystem socket names.

Signed-off-by: CaoRuichuang <create0818@163.com>
---
 tools/testing/selftests/vsock/vmtest.sh | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 86e338886..91e0037d2 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -718,6 +718,7 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
 	local pids pid pidfile
 	local ns0 ns1 port
 	declare -a pids
+	local unixdir
 	local unixfile
 	ns0="global0"
 	ns1="global1"
@@ -736,7 +737,8 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
 	oops_before=$(vm_dmesg_oops_count "${ns0}")
 	warn_before=$(vm_dmesg_warn_count "${ns0}")
 
-	unixfile=$(mktemp -u /tmp/XXXX.sock)
+	unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
+	unixfile="${unixdir}/sock"
 	ip netns exec "${ns1}" \
 		socat TCP-LISTEN:"${TEST_HOST_PORT}",fork \
 			UNIX-CONNECT:"${unixfile}" &
@@ -758,6 +760,7 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
 
 	terminate_pids "${pids[@]}"
 	terminate_pidfiles "${pidfile}"
+	rm -rf "${unixdir}"
 
 	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
 		return "${KSFT_FAIL}"
@@ -814,6 +817,7 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 	local ns0="global0"
 	local ns1="global1"
 	local port=12345
+	local unixdir
 	local unixfile
 	local dmesg_rc
 	local pidfile
@@ -826,7 +830,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 
 	log_host "Setup socat bridge from ns ${ns0} to ns ${ns1} over port ${port}"
 
-	unixfile=$(mktemp -u /tmp/XXXX.sock)
+	unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
+	unixfile="${unixdir}/sock"
 
 	ip netns exec "${ns0}" \
 		socat TCP-LISTEN:"${port}" UNIX-CONNECT:"${unixfile}" &
@@ -845,7 +850,7 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 	if ! vm_start "${pidfile}" "${ns0}"; then
 		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
 		terminate_pids "${pids[@]}"
-		rm -f "${unixfile}"
+		rm -rf "${unixdir}"
 		return "${KSFT_FAIL}"
 	fi
 
@@ -862,7 +867,7 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 
 	terminate_pidfiles "${pidfile}"
 	terminate_pids "${pids[@]}"
-	rm -f "${unixfile}"
+	rm -rf "${unixdir}"
 
 	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
 		return "${KSFT_FAIL}"
-- 
2.39.5 (Apple Git-154)

Re: [PATCH 1/1] selftests: vsock: avoid mktemp -u for Unix socket paths

[Simon Horman]

On Mon, Apr 06, 2026 at 03:57:33AM +0800, CaoRuichuang wrote:
> The namespace tests create temporary Unix socket paths with mktemp -u and
> then hand them to socat. That only prints an unused pathname and leaves
> a race before the socket is created.
>
> Create a private temporary directory with mktemp -d and place the Unix
> socket inside it instead. This keeps the path unique without relying on
> mktemp -u for filesystem socket names.
> 
> Signed-off-by: CaoRuichuang <create0818@163.com>

I think the subject could be improved a bit.
More along the lines of the problem being solved,
less on how it is achieved.

...

> @@ -845,7 +850,7 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
>  	if ! vm_start "${pidfile}" "${ns0}"; then
>  		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
>  		terminate_pids "${pids[@]}"
> -		rm -f "${unixfile}"
> +		rm -rf "${unixdir}"

rm -rf makes me feel queasy.
Can rmdir, and rm, ideally without the -f, be used instead?

		rm "$unixfile"
		rmdir "$unixdir"

>  		return "${KSFT_FAIL}"
>  	fi
>  

...

[PATCH v2] selftests: vsock: avoid races creating Unix socket paths

[Cao Ruichuang]

Signed-off-by: Cao Ruichuang <create0818@163.com>
---
v2:
- retitle the patch to describe the race being fixed
- replace rm -rf with explicit rm and rmdir cleanup

 tools/testing/selftests/vsock/vmtest.sh | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 86e338886b3..c345fa539d3 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -718,6 +718,7 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
 	local pids pid pidfile
 	local ns0 ns1 port
 	declare -a pids
+	local unixdir
 	local unixfile
 	ns0="global0"
 	ns1="global1"
@@ -736,7 +737,8 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
 	oops_before=$(vm_dmesg_oops_count "${ns0}")
 	warn_before=$(vm_dmesg_warn_count "${ns0}")
 
-	unixfile=$(mktemp -u /tmp/XXXX.sock)
+	unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
+	unixfile="${unixdir}/sock"
 	ip netns exec "${ns1}" \
 		socat TCP-LISTEN:"${TEST_HOST_PORT}",fork \
 			UNIX-CONNECT:"${unixfile}" &
@@ -758,6 +760,8 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
 
 	terminate_pids "${pids[@]}"
 	terminate_pidfiles "${pidfile}"
+	rm "${unixfile}"
+	rmdir "${unixdir}"
 
 	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
 		return "${KSFT_FAIL}"
@@ -814,6 +818,7 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 	local ns0="global0"
 	local ns1="global1"
 	local port=12345
+	local unixdir
 	local unixfile
 	local dmesg_rc
 	local pidfile
@@ -826,7 +831,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 
 	log_host "Setup socat bridge from ns ${ns0} to ns ${ns1} over port ${port}"
 
-	unixfile=$(mktemp -u /tmp/XXXX.sock)
+	unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
+	unixfile="${unixdir}/sock"
 
 	ip netns exec "${ns0}" \
 		socat TCP-LISTEN:"${port}" UNIX-CONNECT:"${unixfile}" &
@@ -845,7 +851,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 	if ! vm_start "${pidfile}" "${ns0}"; then
 		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
 		terminate_pids "${pids[@]}"
-		rm -f "${unixfile}"
+		rm "${unixfile}"
+		rmdir "${unixdir}"
 		return "${KSFT_FAIL}"
 	fi
 
@@ -862,7 +869,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
 
 	terminate_pidfiles "${pidfile}"
 	terminate_pids "${pids[@]}"
-	rm -f "${unixfile}"
+	rm "${unixfile}"
+	rmdir "${unixdir}"
 
 	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
 		return "${KSFT_FAIL}"
-- 
2.39.5 (Apple Git-154)

Re: [PATCH v2] selftests: vsock: avoid races creating Unix socket paths

[Stefano Garzarella]

On Fri, Apr 10, 2026 at 11:52:37AM +0800, Cao Ruichuang wrote:

No patch description at all?

>Signed-off-by: Cao Ruichuang <create0818@163.com>
>---
>v2:
>- retitle the patch to describe the race being fixed
>- replace rm -rf with explicit rm and rmdir cleanup
>
> tools/testing/selftests/vsock/vmtest.sh | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
>diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
>index 86e338886b3..c345fa539d3 100755
>--- a/tools/testing/selftests/vsock/vmtest.sh
>+++ b/tools/testing/selftests/vsock/vmtest.sh
>@@ -718,6 +718,7 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
> 	local pids pid pidfile
> 	local ns0 ns1 port
> 	declare -a pids
>+	local unixdir
> 	local unixfile
> 	ns0="global0"
> 	ns1="global1"
>@@ -736,7 +737,8 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
> 	oops_before=$(vm_dmesg_oops_count "${ns0}")
> 	warn_before=$(vm_dmesg_warn_count "${ns0}")
>
>-	unixfile=$(mktemp -u /tmp/XXXX.sock)
>+	unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
>+	unixfile="${unixdir}/sock"
> 	ip netns exec "${ns1}" \
> 		socat TCP-LISTEN:"${TEST_HOST_PORT}",fork \
> 			UNIX-CONNECT:"${unixfile}" &
>@@ -758,6 +760,8 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
>
> 	terminate_pids "${pids[@]}"
> 	terminate_pidfiles "${pidfile}"
>+	rm "${unixfile}"
>+	rmdir "${unixdir}"
>
> 	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
> 		return "${KSFT_FAIL}"
>@@ -814,6 +818,7 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
> 	local ns0="global0"
> 	local ns1="global1"
> 	local port=12345
>+	local unixdir
> 	local unixfile
> 	local dmesg_rc
> 	local pidfile
>@@ -826,7 +831,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
>
> 	log_host "Setup socat bridge from ns ${ns0} to ns ${ns1} over port ${port}"
>
>-	unixfile=$(mktemp -u /tmp/XXXX.sock)
>+	unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
>+	unixfile="${unixdir}/sock"
>
> 	ip netns exec "${ns0}" \
> 		socat TCP-LISTEN:"${port}" UNIX-CONNECT:"${unixfile}" &
>@@ -845,7 +851,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
> 	if ! vm_start "${pidfile}" "${ns0}"; then
> 		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
> 		terminate_pids "${pids[@]}"
>-		rm -f "${unixfile}"
>+		rm "${unixfile}"
>+		rmdir "${unixdir}"
> 		return "${KSFT_FAIL}"
> 	fi
>
>@@ -862,7 +869,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
>
> 	terminate_pidfiles "${pidfile}"
> 	terminate_pids "${pids[@]}"
>-	rm -f "${unixfile}"
>+	rm "${unixfile}"
>+	rmdir "${unixdir}"
>
> 	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
> 		return "${KSFT_FAIL}"
>-- 
>2.39.5 (Apple Git-154)
>
>

Re: [PATCH v2] selftests: vsock: avoid races creating Unix socket paths

[Stefano Garzarella]

On Fri, 10 Apr 2026 at 10:33, Stefano Garzarella <sgarzare@redhat.com> wrote:
>
> On Fri, Apr 10, 2026 at 11:52:37AM +0800, Cao Ruichuang wrote:
>
> No patch description at all?

Also, maybe better to CC Bobby.

Stefano

>
> >Signed-off-by: Cao Ruichuang <create0818@163.com>
> >---
> >v2:
> >- retitle the patch to describe the race being fixed
> >- replace rm -rf with explicit rm and rmdir cleanup
> >
> > tools/testing/selftests/vsock/vmtest.sh | 16 ++++++++++++----
> > 1 file changed, 12 insertions(+), 4 deletions(-)
> >
> >diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
> >index 86e338886b3..c345fa539d3 100755
> >--- a/tools/testing/selftests/vsock/vmtest.sh
> >+++ b/tools/testing/selftests/vsock/vmtest.sh
> >@@ -718,6 +718,7 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
> >       local pids pid pidfile
> >       local ns0 ns1 port
> >       declare -a pids
> >+      local unixdir
> >       local unixfile
> >       ns0="global0"
> >       ns1="global1"
> >@@ -736,7 +737,8 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
> >       oops_before=$(vm_dmesg_oops_count "${ns0}")
> >       warn_before=$(vm_dmesg_warn_count "${ns0}")
> >
> >-      unixfile=$(mktemp -u /tmp/XXXX.sock)
> >+      unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
> >+      unixfile="${unixdir}/sock"
> >       ip netns exec "${ns1}" \
> >               socat TCP-LISTEN:"${TEST_HOST_PORT}",fork \
> >                       UNIX-CONNECT:"${unixfile}" &
> >@@ -758,6 +760,8 @@ test_ns_diff_global_host_connect_to_global_vm_ok() {
> >
> >       terminate_pids "${pids[@]}"
> >       terminate_pidfiles "${pidfile}"
> >+      rm "${unixfile}"
> >+      rmdir "${unixdir}"
> >
> >       if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
> >               return "${KSFT_FAIL}"
> >@@ -814,6 +818,7 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
> >       local ns0="global0"
> >       local ns1="global1"
> >       local port=12345
> >+      local unixdir
> >       local unixfile
> >       local dmesg_rc
> >       local pidfile
> >@@ -826,7 +831,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
> >
> >       log_host "Setup socat bridge from ns ${ns0} to ns ${ns1} over port ${port}"
> >
> >-      unixfile=$(mktemp -u /tmp/XXXX.sock)
> >+      unixdir=$(mktemp -d /tmp/vsock_vmtest_XXXXXX)
> >+      unixfile="${unixdir}/sock"
> >
> >       ip netns exec "${ns0}" \
> >               socat TCP-LISTEN:"${port}" UNIX-CONNECT:"${unixfile}" &
> >@@ -845,7 +851,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
> >       if ! vm_start "${pidfile}" "${ns0}"; then
> >               log_host "failed to start vm (cid=${cid}, ns=${ns0})"
> >               terminate_pids "${pids[@]}"
> >-              rm -f "${unixfile}"
> >+              rm "${unixfile}"
> >+              rmdir "${unixdir}"
> >               return "${KSFT_FAIL}"
> >       fi
> >
> >@@ -862,7 +869,8 @@ test_ns_diff_global_vm_connect_to_global_host_ok() {
> >
> >       terminate_pidfiles "${pidfile}"
> >       terminate_pids "${pids[@]}"
> >-      rm -f "${unixfile}"
> >+      rm "${unixfile}"
> >+      rmdir "${unixdir}"
> >
> >       if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
> >               return "${KSFT_FAIL}"
> >--
> >2.39.5 (Apple Git-154)
> >
> >