From: Alexey Gladkov <gladkov.alexey@gmail.com> To: LKML <linux-kernel@vger.kernel.org>, io-uring@vger.kernel.org, Kernel Hardening <kernel-hardening@lists.openwall.com>, Linux Containers <containers@lists.linux-foundation.org>, linux-mm@kvack.org Cc: Jens Axboe <axboe@kernel.dk>, Kees Cook <keescook@chromium.org>, Jann Horn <jannh@google.com>, Linus Torvalds <torvalds@linux-foundation.org>, Oleg Nesterov <oleg@redhat.com>, "Eric W . Biederman" <ebiederm@xmission.com>, Andrew Morton <akpm@linux-foundation.org>, Alexey Gladkov <legion@kernel.org> Subject: [PATCH v5 7/7] kselftests: Add test to check for rlimit changes in different user namespaces Date: Mon, 1 Feb 2021 15:18:35 +0100 [thread overview] Message-ID: <b6c26cea0d74e321fdded286905708a3dba741c0.1612188590.git.gladkov.alexey@gmail.com> (raw) In-Reply-To: <cover.1612188590.git.gladkov.alexey@gmail.com> The testcase runs few instances of the program with RLIMIT_NPROC=1 from user uid=60000, in different user namespaces. Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/rlimits/.gitignore | 2 + tools/testing/selftests/rlimits/Makefile | 6 + tools/testing/selftests/rlimits/config | 1 + .../selftests/rlimits/rlimits-per-userns.c | 161 ++++++++++++++++++ 5 files changed, 171 insertions(+) create mode 100644 tools/testing/selftests/rlimits/.gitignore create mode 100644 tools/testing/selftests/rlimits/Makefile create mode 100644 tools/testing/selftests/rlimits/config create mode 100644 tools/testing/selftests/rlimits/rlimits-per-userns.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index afbab4aeef3c..4dbeb5686f7b 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -46,6 +46,7 @@ TARGETS += proc TARGETS += pstore TARGETS += ptrace TARGETS += openat2 +TARGETS += rlimits TARGETS += rseq TARGETS += rtc TARGETS += seccomp diff --git a/tools/testing/selftests/rlimits/.gitignore b/tools/testing/selftests/rlimits/.gitignore new file mode 100644 index 000000000000..091021f255b3 --- /dev/null +++ b/tools/testing/selftests/rlimits/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +rlimits-per-userns diff --git a/tools/testing/selftests/rlimits/Makefile b/tools/testing/selftests/rlimits/Makefile new file mode 100644 index 000000000000..03aadb406212 --- /dev/null +++ b/tools/testing/selftests/rlimits/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +CFLAGS += -Wall -O2 -g +TEST_GEN_PROGS := rlimits-per-userns + +include ../lib.mk diff --git a/tools/testing/selftests/rlimits/config b/tools/testing/selftests/rlimits/config new file mode 100644 index 000000000000..416bd53ce982 --- /dev/null +++ b/tools/testing/selftests/rlimits/config @@ -0,0 +1 @@ +CONFIG_USER_NS=y diff --git a/tools/testing/selftests/rlimits/rlimits-per-userns.c b/tools/testing/selftests/rlimits/rlimits-per-userns.c new file mode 100644 index 000000000000..26dc949e93ea --- /dev/null +++ b/tools/testing/selftests/rlimits/rlimits-per-userns.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Author: Alexey Gladkov <gladkov.alexey@gmail.com> + */ +#define _GNU_SOURCE +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/time.h> +#include <sys/resource.h> +#include <sys/prctl.h> +#include <sys/stat.h> + +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <sched.h> +#include <signal.h> +#include <limits.h> +#include <fcntl.h> +#include <errno.h> +#include <err.h> + +#define NR_CHILDS 2 + +static char *service_prog; +static uid_t user = 60000; +static uid_t group = 60000; + +static void setrlimit_nproc(rlim_t n) +{ + pid_t pid = getpid(); + struct rlimit limit = { + .rlim_cur = n, + .rlim_max = n + }; + + warnx("(pid=%d): Setting RLIMIT_NPROC=%ld", pid, n); + + if (setrlimit(RLIMIT_NPROC, &limit) < 0) + err(EXIT_FAILURE, "(pid=%d): setrlimit(RLIMIT_NPROC)", pid); +} + +static pid_t fork_child(void) +{ + pid_t pid = fork(); + + if (pid < 0) + err(EXIT_FAILURE, "fork"); + + if (pid > 0) + return pid; + + pid = getpid(); + + warnx("(pid=%d): New process starting ...", pid); + + if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) + err(EXIT_FAILURE, "(pid=%d): prctl(PR_SET_PDEATHSIG)", pid); + + signal(SIGUSR1, SIG_DFL); + + warnx("(pid=%d): Changing to uid=%d, gid=%d", pid, user, group); + + if (setgid(group) < 0) + err(EXIT_FAILURE, "(pid=%d): setgid(%d)", pid, group); + if (setuid(user) < 0) + err(EXIT_FAILURE, "(pid=%d): setuid(%d)", pid, user); + + warnx("(pid=%d): Service running ...", pid); + + warnx("(pid=%d): Unshare user namespace", pid); + if (unshare(CLONE_NEWUSER) < 0) + err(EXIT_FAILURE, "unshare(CLONE_NEWUSER)"); + + char *const argv[] = { "service", NULL }; + char *const envp[] = { "I_AM_SERVICE=1", NULL }; + + warnx("(pid=%d): Executing real service ...", pid); + + execve(service_prog, argv, envp); + err(EXIT_FAILURE, "(pid=%d): execve", pid); +} + +int main(int argc, char **argv) +{ + size_t i; + pid_t child[NR_CHILDS]; + int wstatus[NR_CHILDS]; + int childs = NR_CHILDS; + pid_t pid; + + if (getenv("I_AM_SERVICE")) { + pause(); + exit(EXIT_SUCCESS); + } + + service_prog = argv[0]; + pid = getpid(); + + warnx("(pid=%d) Starting testcase", pid); + + /* + * This rlimit is not a problem for root because it can be exceeded. + */ + setrlimit_nproc(1); + + for (i = 0; i < NR_CHILDS; i++) { + child[i] = fork_child(); + wstatus[i] = 0; + usleep(250000); + } + + while (1) { + for (i = 0; i < NR_CHILDS; i++) { + if (child[i] <= 0) + continue; + + errno = 0; + pid_t ret = waitpid(child[i], &wstatus[i], WNOHANG); + + if (!ret || (!WIFEXITED(wstatus[i]) && !WIFSIGNALED(wstatus[i]))) + continue; + + if (ret < 0 && errno != ECHILD) + warn("(pid=%d): waitpid(%d)", pid, child[i]); + + child[i] *= -1; + childs -= 1; + } + + if (!childs) + break; + + usleep(250000); + + for (i = 0; i < NR_CHILDS; i++) { + if (child[i] <= 0) + continue; + kill(child[i], SIGUSR1); + } + } + + for (i = 0; i < NR_CHILDS; i++) { + if (WIFEXITED(wstatus[i])) + warnx("(pid=%d): pid %d exited, status=%d", + pid, -child[i], WEXITSTATUS(wstatus[i])); + else if (WIFSIGNALED(wstatus[i])) + warnx("(pid=%d): pid %d killed by signal %d", + pid, -child[i], WTERMSIG(wstatus[i])); + + if (WIFSIGNALED(wstatus[i]) && WTERMSIG(wstatus[i]) == SIGUSR1) + continue; + + warnx("(pid=%d): Test failed", pid); + exit(EXIT_FAILURE); + } + + warnx("(pid=%d): Test passed", pid); + exit(EXIT_SUCCESS); +} -- 2.29.2 _______________________________________________ Containers mailing list Containers@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/containers
WARNING: multiple messages have this Message-ID (diff)
From: Alexey Gladkov <gladkov.alexey@gmail.com> To: LKML <linux-kernel@vger.kernel.org>, io-uring@vger.kernel.org, Kernel Hardening <kernel-hardening@lists.openwall.com>, Linux Containers <containers@lists.linux-foundation.org>, linux-mm@kvack.org Cc: Alexey Gladkov <legion@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Christian Brauner <christian.brauner@ubuntu.com>, "Eric W . Biederman" <ebiederm@xmission.com>, Jann Horn <jannh@google.com>, Jens Axboe <axboe@kernel.dk>, Kees Cook <keescook@chromium.org>, Linus Torvalds <torvalds@linux-foundation.org>, Oleg Nesterov <oleg@redhat.com> Subject: [PATCH v5 7/7] kselftests: Add test to check for rlimit changes in different user namespaces Date: Mon, 1 Feb 2021 15:18:35 +0100 [thread overview] Message-ID: <b6c26cea0d74e321fdded286905708a3dba741c0.1612188590.git.gladkov.alexey@gmail.com> (raw) In-Reply-To: <cover.1612188590.git.gladkov.alexey@gmail.com> The testcase runs few instances of the program with RLIMIT_NPROC=1 from user uid=60000, in different user namespaces. Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/rlimits/.gitignore | 2 + tools/testing/selftests/rlimits/Makefile | 6 + tools/testing/selftests/rlimits/config | 1 + .../selftests/rlimits/rlimits-per-userns.c | 161 ++++++++++++++++++ 5 files changed, 171 insertions(+) create mode 100644 tools/testing/selftests/rlimits/.gitignore create mode 100644 tools/testing/selftests/rlimits/Makefile create mode 100644 tools/testing/selftests/rlimits/config create mode 100644 tools/testing/selftests/rlimits/rlimits-per-userns.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index afbab4aeef3c..4dbeb5686f7b 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -46,6 +46,7 @@ TARGETS += proc TARGETS += pstore TARGETS += ptrace TARGETS += openat2 +TARGETS += rlimits TARGETS += rseq TARGETS += rtc TARGETS += seccomp diff --git a/tools/testing/selftests/rlimits/.gitignore b/tools/testing/selftests/rlimits/.gitignore new file mode 100644 index 000000000000..091021f255b3 --- /dev/null +++ b/tools/testing/selftests/rlimits/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +rlimits-per-userns diff --git a/tools/testing/selftests/rlimits/Makefile b/tools/testing/selftests/rlimits/Makefile new file mode 100644 index 000000000000..03aadb406212 --- /dev/null +++ b/tools/testing/selftests/rlimits/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +CFLAGS += -Wall -O2 -g +TEST_GEN_PROGS := rlimits-per-userns + +include ../lib.mk diff --git a/tools/testing/selftests/rlimits/config b/tools/testing/selftests/rlimits/config new file mode 100644 index 000000000000..416bd53ce982 --- /dev/null +++ b/tools/testing/selftests/rlimits/config @@ -0,0 +1 @@ +CONFIG_USER_NS=y diff --git a/tools/testing/selftests/rlimits/rlimits-per-userns.c b/tools/testing/selftests/rlimits/rlimits-per-userns.c new file mode 100644 index 000000000000..26dc949e93ea --- /dev/null +++ b/tools/testing/selftests/rlimits/rlimits-per-userns.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Author: Alexey Gladkov <gladkov.alexey@gmail.com> + */ +#define _GNU_SOURCE +#include <sys/types.h> +#include <sys/wait.h> +#include <sys/time.h> +#include <sys/resource.h> +#include <sys/prctl.h> +#include <sys/stat.h> + +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <sched.h> +#include <signal.h> +#include <limits.h> +#include <fcntl.h> +#include <errno.h> +#include <err.h> + +#define NR_CHILDS 2 + +static char *service_prog; +static uid_t user = 60000; +static uid_t group = 60000; + +static void setrlimit_nproc(rlim_t n) +{ + pid_t pid = getpid(); + struct rlimit limit = { + .rlim_cur = n, + .rlim_max = n + }; + + warnx("(pid=%d): Setting RLIMIT_NPROC=%ld", pid, n); + + if (setrlimit(RLIMIT_NPROC, &limit) < 0) + err(EXIT_FAILURE, "(pid=%d): setrlimit(RLIMIT_NPROC)", pid); +} + +static pid_t fork_child(void) +{ + pid_t pid = fork(); + + if (pid < 0) + err(EXIT_FAILURE, "fork"); + + if (pid > 0) + return pid; + + pid = getpid(); + + warnx("(pid=%d): New process starting ...", pid); + + if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) + err(EXIT_FAILURE, "(pid=%d): prctl(PR_SET_PDEATHSIG)", pid); + + signal(SIGUSR1, SIG_DFL); + + warnx("(pid=%d): Changing to uid=%d, gid=%d", pid, user, group); + + if (setgid(group) < 0) + err(EXIT_FAILURE, "(pid=%d): setgid(%d)", pid, group); + if (setuid(user) < 0) + err(EXIT_FAILURE, "(pid=%d): setuid(%d)", pid, user); + + warnx("(pid=%d): Service running ...", pid); + + warnx("(pid=%d): Unshare user namespace", pid); + if (unshare(CLONE_NEWUSER) < 0) + err(EXIT_FAILURE, "unshare(CLONE_NEWUSER)"); + + char *const argv[] = { "service", NULL }; + char *const envp[] = { "I_AM_SERVICE=1", NULL }; + + warnx("(pid=%d): Executing real service ...", pid); + + execve(service_prog, argv, envp); + err(EXIT_FAILURE, "(pid=%d): execve", pid); +} + +int main(int argc, char **argv) +{ + size_t i; + pid_t child[NR_CHILDS]; + int wstatus[NR_CHILDS]; + int childs = NR_CHILDS; + pid_t pid; + + if (getenv("I_AM_SERVICE")) { + pause(); + exit(EXIT_SUCCESS); + } + + service_prog = argv[0]; + pid = getpid(); + + warnx("(pid=%d) Starting testcase", pid); + + /* + * This rlimit is not a problem for root because it can be exceeded. + */ + setrlimit_nproc(1); + + for (i = 0; i < NR_CHILDS; i++) { + child[i] = fork_child(); + wstatus[i] = 0; + usleep(250000); + } + + while (1) { + for (i = 0; i < NR_CHILDS; i++) { + if (child[i] <= 0) + continue; + + errno = 0; + pid_t ret = waitpid(child[i], &wstatus[i], WNOHANG); + + if (!ret || (!WIFEXITED(wstatus[i]) && !WIFSIGNALED(wstatus[i]))) + continue; + + if (ret < 0 && errno != ECHILD) + warn("(pid=%d): waitpid(%d)", pid, child[i]); + + child[i] *= -1; + childs -= 1; + } + + if (!childs) + break; + + usleep(250000); + + for (i = 0; i < NR_CHILDS; i++) { + if (child[i] <= 0) + continue; + kill(child[i], SIGUSR1); + } + } + + for (i = 0; i < NR_CHILDS; i++) { + if (WIFEXITED(wstatus[i])) + warnx("(pid=%d): pid %d exited, status=%d", + pid, -child[i], WEXITSTATUS(wstatus[i])); + else if (WIFSIGNALED(wstatus[i])) + warnx("(pid=%d): pid %d killed by signal %d", + pid, -child[i], WTERMSIG(wstatus[i])); + + if (WIFSIGNALED(wstatus[i]) && WTERMSIG(wstatus[i]) == SIGUSR1) + continue; + + warnx("(pid=%d): Test failed", pid); + exit(EXIT_FAILURE); + } + + warnx("(pid=%d): Test passed", pid); + exit(EXIT_SUCCESS); +} -- 2.29.2
next prev parent reply other threads:[~2021-02-01 14:21 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-02-01 14:18 [PATCH v5 0/7] Count rlimits in each user namespace Alexey Gladkov 2021-02-01 14:18 ` Alexey Gladkov 2021-02-01 14:18 ` [PATCH v5 1/7] Increase size of ucounts to atomic_long_t Alexey Gladkov 2021-02-01 14:18 ` Alexey Gladkov 2021-02-01 14:18 ` [PATCH v5 2/7] Add a reference to ucounts for each cred Alexey Gladkov 2021-02-01 14:18 ` Alexey Gladkov 2021-02-01 14:18 ` [PATCH v5 3/7] Reimplement RLIMIT_NPROC on top of ucounts Alexey Gladkov 2021-02-01 14:18 ` Alexey Gladkov 2021-02-05 2:55 ` c632dadc10: BUG:KASAN:null-ptr-deref_in_is_ucounts_overlimit kernel test robot 2021-02-05 2:55 ` kernel test robot 2021-02-05 2:55 ` kernel test robot 2021-02-01 14:18 ` [PATCH v5 4/7] Reimplement RLIMIT_MSGQUEUE on top of ucounts Alexey Gladkov 2021-02-01 14:18 ` Alexey Gladkov 2021-02-01 14:18 ` [PATCH v5 5/7] Reimplement RLIMIT_SIGPENDING " Alexey Gladkov 2021-02-01 14:18 ` Alexey Gladkov 2021-02-01 14:18 ` [PATCH v5 6/7] Reimplement RLIMIT_MEMLOCK " Alexey Gladkov 2021-02-01 14:18 ` Alexey Gladkov 2021-02-04 7:11 ` 0ac0c30c8f: WARNING:at_kernel/ucount.c:#dec_rlimit_ucounts kernel test robot 2021-02-04 7:11 ` kernel test robot 2021-02-04 7:11 ` kernel test robot 2021-02-01 14:18 ` Alexey Gladkov [this message] 2021-02-01 14:18 ` [PATCH v5 7/7] kselftests: Add test to check for rlimit changes in different user namespaces Alexey Gladkov
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