linux/kernel
Waiman Long b22faa21b6 sched/core: Fix use-after-free bug in dup_user_cpus_ptr()
commit 87ca4f9efb upstream.

Since commit 07ec77a1d4 ("sched: Allow task CPU affinity to be
restricted on asymmetric systems"), the setting and clearing of
user_cpus_ptr are done under pi_lock for arm64 architecture. However,
dup_user_cpus_ptr() accesses user_cpus_ptr without any lock
protection. Since sched_setaffinity() can be invoked from another
process, the process being modified may be undergoing fork() at
the same time.  When racing with the clearing of user_cpus_ptr in
__set_cpus_allowed_ptr_locked(), it can lead to user-after-free and
possibly double-free in arm64 kernel.

Commit 8f9ea86fdf ("sched: Always preserve the user requested
cpumask") fixes this problem as user_cpus_ptr, once set, will never
be cleared in a task's lifetime. However, this bug was re-introduced
in commit 851a723e45 ("sched: Always clear user_cpus_ptr in
do_set_cpus_allowed()") which allows the clearing of user_cpus_ptr in
do_set_cpus_allowed(). This time, it will affect all arches.

Fix this bug by always clearing the user_cpus_ptr of the newly
cloned/forked task before the copying process starts and check the
user_cpus_ptr state of the source task under pi_lock.

Note to stable, this patch won't be applicable to stable releases.
Just copy the new dup_user_cpus_ptr() function over.

Fixes: 07ec77a1d4 ("sched: Allow task CPU affinity to be restricted on asymmetric systems")
Fixes: 851a723e45 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()")
Reported-by: David Wang 王标 <wangbiao3@xiaomi.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221231041120.440785-2-longman@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18 11:48:52 +01:00
..
bpf bpf: Prevent decl_tag from being referenced in func_proto arg 2022-12-31 13:14:42 +01:00
cgroup memcg: fix possible use-after-free in memcg_write_event_control() 2022-12-14 11:37:19 +01:00
configs
debug lockdown: also lock down previous kgdb use 2022-05-25 09:57:37 +02:00
dma swiotlb: max mapping size takes min align mask into account 2022-10-05 10:39:40 +02:00
entry lockdep: Fix -Wunused-parameter for _THIS_IP_ 2022-09-20 12:39:42 +02:00
events perf/core: Call LSM hook after copying perf_event_attr 2023-01-12 11:58:53 +01:00
futex futex: Resend potentially swallowed owner death notification 2022-12-31 13:14:04 +01:00
gcov gcov: add support for checksum field 2022-12-31 13:14:47 +01:00
irq genirq/irqdesc: Don't try to remove non-existing sysfs files 2022-12-31 13:14:03 +01:00
kcsan kcsan: Instrument memcpy/memset/memmove with newer Clang 2023-01-12 11:58:48 +01:00
livepatch livepatch: fix race between fork and KLP transition 2022-10-26 12:34:30 +02:00
locking lockdep: Fix -Wunused-parameter for _THIS_IP_ 2022-09-20 12:39:42 +02:00
power PM: hibernate: Fix mistake in kerneldoc comment 2022-12-31 13:14:01 +01:00
printk printk: wake waiters for safe and NMI contexts 2022-06-09 10:22:49 +02:00
rcu rcu-tasks: Simplify trc_read_check_handler() atomic operations 2023-01-12 11:58:49 +01:00
sched sched/core: Fix use-after-free bug in dup_user_cpus_ptr() 2023-01-18 11:48:52 +01:00
time timekeeping: contribute wall clock to rng on time change 2022-08-17 14:24:24 +02:00
trace tracing: Fix issue of missing one synthetic field 2023-01-12 11:59:03 +01:00
.gitignore
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-12-31 13:14:40 +01:00
async.c Revert "module, async: async_synchronize_full() on module init iff async is used" 2022-02-23 12:03:07 +01:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-31 17:16:33 +02:00
audit_tree.c audit: move put_tree() to avoid trim_trees refcount underflow and UAF 2021-08-24 18:52:36 -04:00
audit_watch.c
audit.c audit: improve audit queue handling when "audit=1" on cmdline 2022-02-08 18:34:03 +01:00
audit.h audit: log AUDIT_TIME_* records only from rules 2022-04-08 14:23:06 +02:00
auditfilter.c
auditsc.c audit: log AUDIT_TIME_* records only from rules 2022-04-08 14:23:06 +02:00
backtracetest.c
bounds.c
capability.c
cfi.c cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle 2022-06-22 14:22:04 +02:00
compat.c arch: remove compat_alloc_user_space 2021-09-08 15:32:35 -07:00
configs.c
context_tracking.c
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-08-16 18:55:32 +02:00
cpu.c cpu/hotplug: Do not bail-out in DYING/STARTING sections 2022-12-31 13:14:04 +01:00
crash_core.c kernel/crash_core: suppress unknown crashkernel parameter warning 2021-12-29 12:28:49 +01:00
crash_dump.c
cred.c ucounts: Base set_cred_ucounts changes on the real user 2022-02-23 12:03:20 +01:00
delayacct.c delayacct: Add sysctl to enable at runtime 2021-05-12 11:43:25 +02:00
dma.c
exec_domain.c
exit.c fix race between exit_itimers() and /proc/pid/timers 2022-07-21 21:24:11 +02:00
extable.c
fail_function.c
fork.c seccomp: Move copy_seccomp() to no failure path. 2022-12-31 13:14:00 +01:00
freezer.c sched: Add get_current_state() 2021-06-18 11:43:08 +02:00
gen_kheaders.sh kbuild: clean up ${quiet} checks in shell scripts 2021-05-27 04:01:50 +09:00
groups.c
hung_task.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
iomem.c
irq_work.c irq_work: Make irq_work_queue() NMI-safe again 2021-06-10 10:00:08 +02:00
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c module: add printk formats to add module build ID to stacktraces 2021-07-08 11:48:22 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
Kconfig.preempt sched/core: Disable CONFIG_SCHED_CORE by default 2021-06-28 22:43:05 +02:00
kcov.c
kexec_core.c Merge branch 'rework/printk_safe-removal' into for-linus 2021-08-30 16:36:10 +02:00
kexec_elf.c
kexec_file.c ima: force signature verification when CONFIG_KEXEC_SIG is configured 2022-07-21 21:24:29 +02:00
kexec_internal.h
kexec.c kexec: avoid compat_alloc_user_space 2021-09-08 15:32:34 -07:00
kheaders.c
kmod.c
kprobes.c kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case 2022-11-26 09:24:50 +01:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2021-06-29 17:29:11 -07:00
latencytop.c
Makefile futex: Move to kernel/futex/ 2022-12-31 13:14:04 +01:00
module_signature.c
module_signing.c
module-internal.h
module.c module: fix [e_shstrndx].sh_size=0 OOB access 2022-07-12 16:35:09 +02:00
notifier.c notifier: Remove atomic_notifier_call_chain_robust() 2021-08-16 18:55:32 +02:00
nsproxy.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
padata.c padata: Fix list iterator in padata_do_serial() 2022-12-31 13:14:24 +01:00
panic.c Merge branch 'rework/printk_safe-removal' into for-linus 2021-08-30 16:36:10 +02:00
params.c params: lift param_set_uint_minmax to common code 2021-08-16 14:42:22 +02:00
pid_namespace.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
pid.c kernel/pid.c: implement additional checks upon pidfd_create() parameters 2021-08-10 12:53:07 +02:00
profile.c profiling: fix shift too large makes kernel panic 2022-08-17 14:24:04 +02:00
ptrace.c ptrace: Reimplement PTRACE_KILL by always sending SIGKILL 2022-06-09 10:22:29 +02:00
range.c
reboot.c reboot: Add hardware protection power-off 2021-06-21 13:08:36 +01:00
regset.c
relay.c relay: fix type mismatch when allocating memory in relay_create_buf() 2022-12-31 13:14:05 +01:00
resource_kunit.c
resource.c kernel/resource: fix kfree() of bootmem memory again 2022-04-08 14:23:43 +02:00
rseq.c rseq: Remove broken uapi field layout on 32-bit little endian 2022-04-08 14:23:10 +02:00
scftorture.c scftorture: Fix distribution of short handler delays 2022-06-09 10:22:46 +02:00
scs.c scs: Release kasan vmalloc poison in scs_free process 2021-11-18 19:16:29 +01:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2022-02-16 12:56:38 +01:00
signal.c signal handling: don't use BUG_ON() for debugging 2022-07-21 21:24:42 +02:00
smp.c locking/csd_lock: Change csdlock_debug from early_param to __setup 2022-08-17 14:24:24 +02:00
smpboot.c smpboot: Replace deprecated CPU-hotplug functions. 2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c genirq: Change force_irqthreads to a static key 2021-08-10 22:50:07 +02:00
stackleak.c gcc-plugins/stackleak: Use noinstr in favor of notrace 2022-02-23 12:03:07 +01:00
stacktrace.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2022-04-13 20:59:28 +02:00
static_call_inline.c static_call: Don't make __static_call_return0 static 2022-04-13 20:59:28 +02:00
static_call.c static_call: Don't make __static_call_return0 static 2022-04-13 20:59:28 +02:00
stop_machine.c
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-31 17:16:33 +02:00
sys.c ucounts: Move RLIMIT_NPROC handling after set_user 2022-02-23 12:03:20 +01:00
sysctl-test.c kernel/sysctl-test: Remove some casts which are no-longer required 2021-06-23 16:41:24 -06:00
sysctl.c proc: proc_skip_spaces() shouldn't think it is working on C strings 2022-12-08 11:28:45 +01:00
task_work.c
taskstats.c
test_kprobes.c
torture.c torture: Replace deprecated CPU-hotplug functions. 2021-08-10 10:48:07 -07:00
tracepoint.c tracepoint: Fix kerneldoc comments 2021-08-16 11:39:51 -04:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-01-27 11:05:35 +01:00
ucount.c ucounts: Handle wrapping in is_ucounts_overlimit 2022-02-23 12:03:20 +01:00
uid16.c
uid16.h
umh.c
up.c A set of locking related fixes and updates: 2021-05-09 13:07:03 -07:00
user_namespace.c ucounts: Fix systemd LimitNPROC with private users regression 2022-03-08 19:12:42 +01:00
user-return-notifier.c
user.c fs/epoll: use a per-cpu counter for user's watches count 2021-09-08 11:50:27 -07:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname_sysctl.c
utsname.c
watch_queue.c watch_queue: Fix missing locking in add_watch_to_object() 2022-08-03 12:03:43 +02:00
watchdog_hld.c
watchdog.c watchdog: export lockup_detector_reconfigure 2022-08-25 11:40:43 +02:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00
workqueue.c workqueue: don't skip lockdep work dependency in cancel_work_sync() 2022-09-28 11:11:56 +02:00