From 40305d389e8a8d19f4b98cf4d36213fdf281e5b3 Mon Sep 17 00:00:00 2001 From: Hongxu Jia Date: Sun, 29 Aug 2021 06:52:35 -0700 Subject: glibc: fix create thread failed in unprivileged process Since upstream commit [d8ea0d0168 Add an internal wrapper for clone, clone2 and clone3] applied, start a unprivileged container (docker run without --privileged), it creates a thread failed in container. In commit d8ea0d0168, it calls __clone3 if HAVE_CLONE3_WAPPER is defined. If __clone3 returns -1 with ENOSYS, fall back to clone or clone2. As known from [1], cloneXXX fails with EPERM if CLONE_NEWCGROUP, CLONE_NEWIPC, CLONE_NEWNET, CLONE_NEWNS, CLONE_NEWPID, or CLONE_NEWUTS was specified by an unprivileged process (process without CAP_SYS_ADMIN) [1] https://man7.org/linux/man-pages/man2/clone3.2.html So if __clone3 returns -1 with EPERM, fall back to clone or clone2 could fix the issue. (From OE-Core rev: 234a3e84640c1bb6df5fa4d3d7089a854b19d108) Signed-off-by: Hongxu Jia Signed-off-by: Richard Purdie --- ...thread-failed-in-unprivileged-process-BZ-.patch | 79 ++++++++++++++++++++++ meta/recipes-core/glibc/glibc_2.34.bb | 1 + 2 files changed, 80 insertions(+) create mode 100644 meta/recipes-core/glibc/glibc/0001-fix-create-thread-failed-in-unprivileged-process-BZ-.patch (limited to 'meta') diff --git a/meta/recipes-core/glibc/glibc/0001-fix-create-thread-failed-in-unprivileged-process-BZ-.patch b/meta/recipes-core/glibc/glibc/0001-fix-create-thread-failed-in-unprivileged-process-BZ-.patch new file mode 100644 index 0000000000..3283dd7ad8 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0001-fix-create-thread-failed-in-unprivileged-process-BZ-.patch @@ -0,0 +1,79 @@ +From a8bc44936202692edcd82a48c07d7cf27d6ed8ee Mon Sep 17 00:00:00 2001 +From: Hongxu Jia +Date: Sun, 29 Aug 2021 20:49:16 +0800 +Subject: [PATCH] fix create thread failed in unprivileged process [BZ #28287] + +Since commit [d8ea0d0168 Add an internal wrapper for clone, clone2 and clone3] +applied, start a unprivileged container (docker run without --privileged), +it creates a thread failed in container. + +In commit d8ea0d0168, it calls __clone3 if HAVE_CLONE3_WAPPER is defined. If +__clone3 returns -1 with ENOSYS, fall back to clone or clone2. + +As known from [1], cloneXXX fails with EPERM if CLONE_NEWCGROUP, +CLONE_NEWIPC, CLONE_NEWNET, CLONE_NEWNS, CLONE_NEWPID, or CLONE_NEWUTS +was specified by an unprivileged process (process without CAP_SYS_ADMIN) + +[1] https://man7.org/linux/man-pages/man2/clone3.2.html + +So if __clone3 returns -1 with EPERM, fall back to clone or clone2 could +fix the issue. Here are the test steps: + +1) Prepare test code +cat > conftest.c < + #include + +int check_me = 0; +void* func(void* data) {check_me = 42; printf("start thread: check_me %d\n", check_me); return &check_me;} +int main() +{ + pthread_t t; + void *ret; + pthread_create (&t, 0, func, 0); + pthread_join (t, &ret); + printf("check_me %d, p %p\n", check_me, &ret); + return (check_me != 42 || ret != &check_me); +} + +ENDOF + +2) Compile +gcc -o conftest -pthread conftest.c + +3) Start a container with glibc 2.34 installed +[skip details] +docker run -it bash + +4) Run conftest without this patch +$ ./conftest +check_me 0, p 0x7ffd91ccd400 + +5) Run conftest with this patch +$ ./conftest +start thread: check_me 42 +check_me 42, p 0x7ffe253c6f20 + +Upstream-Status: Submitted [libc-alpha@sourceware.org] + +Signed-off-by: Hongxu Jia +--- + sysdeps/unix/sysv/linux/clone-internal.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/sysdeps/unix/sysv/linux/clone-internal.c b/sysdeps/unix/sysv/linux/clone-internal.c +index 979f7880be..97101994e8 100644 +--- a/sysdeps/unix/sysv/linux/clone-internal.c ++++ b/sysdeps/unix/sysv/linux/clone-internal.c +@@ -52,7 +52,7 @@ __clone_internal (struct clone_args *cl_args, + /* Try clone3 first. */ + int saved_errno = errno; + ret = __clone3 (cl_args, sizeof (*cl_args), func, arg); +- if (ret != -1 || errno != ENOSYS) ++ if (ret != -1 || (errno != ENOSYS && errno != EPERM)) + return ret; + + /* NB: Restore errno since errno may be checked against non-zero +-- +2.30.2 + diff --git a/meta/recipes-core/glibc/glibc_2.34.bb b/meta/recipes-core/glibc/glibc_2.34.bb index eafc0216ff..6dc315c349 100644 --- a/meta/recipes-core/glibc/glibc_2.34.bb +++ b/meta/recipes-core/glibc/glibc_2.34.bb @@ -57,6 +57,7 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \ file://0030-powerpc-Do-not-ask-compiler-for-finding-arch.patch \ file://0001-CVE-2021-38604.patch \ file://0002-CVE-2021-38604.patch \ + file://0001-fix-create-thread-failed-in-unprivileged-process-BZ-.patch \ " S = "${WORKDIR}/git" B = "${WORKDIR}/build-${TARGET_SYS}" -- cgit v1.2.3-54-g00ecf