The patch titled
Subject: proc: test /proc/sysvipc vs setns(CLONE_NEWIPC)
has been added to the -mm tree. Its filename is
proc-test-proc-sysvipc-vs-setnsclone_newipc.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/proc-test-proc-sysvipc-vs-setnsclone_newipc.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/proc-test-proc-sysvipc-vs-setnsclone_newipc.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: proc: test /proc/sysvipc vs setns(CLONE_NEWIPC)
I thought that /proc/sysvipc has the same bug as /proc/net
commit 1fde6f21d90f8ba5da3cb9c54ca991ed72696c43
proc: fix /proc/net/* after setns(2)
However, it doesn't! /proc/sysvipc files do
get_ipc_ns(current->nsproxy->ipc_ns);
in their open() hook and avoid the problem.
Keep the test, maybe /proc/sysvipc will become broken someday :-\
Link: http://lkml.kernel.org/r/20190706180146.GA21015@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/proc/.gitignore | 1
tools/testing/selftests/proc/Makefile | 1
tools/testing/selftests/proc/setns-sysvipc.c | 133 +++++++++++++++++
3 files changed, 135 insertions(+)
--- a/tools/testing/selftests/proc/.gitignore~proc-test-proc-sysvipc-vs-setnsclone_newipc
+++ a/tools/testing/selftests/proc/.gitignore
@@ -12,4 +12,5 @@
/read
/self
/setns-dcache
+/setns-sysvipc
/thread-self
--- a/tools/testing/selftests/proc/Makefile~proc-test-proc-sysvipc-vs-setnsclone_newipc
+++ a/tools/testing/selftests/proc/Makefile
@@ -17,6 +17,7 @@ TEST_GEN_PROGS += proc-uptime-002
TEST_GEN_PROGS += read
TEST_GEN_PROGS += self
TEST_GEN_PROGS += setns-dcache
+TEST_GEN_PROGS += setns-sysvipc
TEST_GEN_PROGS += thread-self
include ../lib.mk
--- /dev/null
+++ a/tools/testing/selftests/proc/setns-sysvipc.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright © 2019 Alexey Dobriyan <adobriyan@xxxxxxxxx>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/*
+ * Test that setns(CLONE_NEWIPC) points to new /proc/sysvipc content even
+ * if old one is in dcache.
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+
+static pid_t pid = -1;
+
+static void f(void)
+{
+ if (pid > 0) {
+ kill(pid, SIGTERM);
+ }
+}
+
+int main(void)
+{
+ int fd[2];
+ char _ = 0;
+ int nsfd;
+
+ atexit(f);
+
+ /* Check for priviledges and syscall availability straight away. */
+ if (unshare(CLONE_NEWIPC) == -1) {
+ if (errno == ENOSYS || errno == EPERM) {
+ return 4;
+ }
+ return 1;
+ }
+ /* Distinguisher between two otherwise empty IPC namespaces. */
+ if (shmget(IPC_PRIVATE, 1, IPC_CREAT) == -1) {
+ return 1;
+ }
+
+ if (pipe(fd) == -1) {
+ return 1;
+ }
+
+ pid = fork();
+ if (pid == -1) {
+ return 1;
+ }
+
+ if (pid == 0) {
+ if (unshare(CLONE_NEWIPC) == -1) {
+ return 1;
+ }
+
+ if (write(fd[1], &_, 1) != 1) {
+ return 1;
+ }
+
+ pause();
+
+ return 0;
+ }
+
+ if (read(fd[0], &_, 1) != 1) {
+ return 1;
+ }
+
+ {
+ char buf[64];
+ snprintf(buf, sizeof(buf), "/proc/%u/ns/ipc", pid);
+ nsfd = open(buf, O_RDONLY);
+ if (nsfd == -1) {
+ return 1;
+ }
+ }
+
+ /* Reliably pin dentry into dcache. */
+ (void)open("/proc/sysvipc/shm", O_RDONLY);
+
+ if (setns(nsfd, CLONE_NEWIPC) == -1) {
+ return 1;
+ }
+
+ kill(pid, SIGTERM);
+ pid = 0;
+
+ {
+ char buf[4096];
+ ssize_t rv;
+ int fd;
+
+ fd = open("/proc/sysvipc/shm", O_RDONLY);
+ if (fd == -1) {
+ return 1;
+ }
+
+#define S32 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n"
+#define S64 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n"
+ rv = read(fd, buf, sizeof(buf));
+ if (rv == strlen(S32)) {
+ assert(memcmp(buf, S32, strlen(S32)) == 0);
+ } else if (rv == strlen(S64)) {
+ assert(memcmp(buf, S64, strlen(S64)) == 0);
+ } else {
+ assert(0);
+ }
+ }
+
+ return 0;
+}
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
ramfs-support-o_tmpfile.patch
swap-ifdef-struct-vm_area_struct-swap_readahead_info.patch
proc-hide-segfault-at-ffffffffff600000-dmesg-spam.patch
add-typeof_member-macro.patch
proc-use-typeof_member-macro.patch
proc-test-proc-sysvipc-vs-setnsclone_newipc.patch
tweak-list_poison2-for-better-code-generation-on-x86_64.patch
elf-delete-stale-comment.patch
signal-reorder-struct-sighand_struct.patch
