TencentOS-kernel/kernel
Eric W. Biederman 1b45f8b772 exec: Transform exec_update_mutex into a rw_semaphore
[ Upstream commit f7cfd871ae0c5008d94b6f66834e7845caa93c15 ]

Recently syzbot reported[0] that there is a deadlock amongst the users
of exec_update_mutex.  The problematic lock ordering found by lockdep
was:

   perf_event_open  (exec_update_mutex -> ovl_i_mutex)
   chown            (ovl_i_mutex       -> sb_writes)
   sendfile         (sb_writes         -> p->lock)
     by reading from a proc file and writing to overlayfs
   proc_pid_syscall (p->lock           -> exec_update_mutex)

While looking at possible solutions it occured to me that all of the
users and possible users involved only wanted to state of the given
process to remain the same.  They are all readers.  The only writer is
exec.

There is no reason for readers to block on each other.  So fix
this deadlock by transforming exec_update_mutex into a rw_semaphore
named exec_update_lock that only exec takes for writing.

Cc: Jann Horn <jannh@google.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christopher Yeoh <cyeoh@au1.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Fixes: eea9673250db ("exec: Add exec_update_mutex to replace cred_guard_mutex")
[0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com
Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/87ft4mbqen.fsf@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-12 12:51:05 +08:00
..
bpf bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback 2021-03-16 16:44:00 +08:00
cgroup cgroup: Fix memory leak when parsing multiple source parameters 2021-03-16 16:43:52 +08:00
configs Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
debug kgdb: Make "kgdbcon" work properly with "kgdb_earlycon" 2021-03-16 16:39:45 +08:00
dma swiotlb: fix "x86: Don't panic if can not alloc buffer for swiotlb" 2021-03-16 16:40:57 +08:00
events exec: Transform exec_update_mutex into a rw_semaphore 2021-04-12 12:51:05 +08:00
gcov gcov: add support for GCC 10.1 2021-03-16 16:36:10 +08:00
irq genirq/irqdomain: Don't try to free an interrupt that has no mapping 2021-03-16 16:42:56 +08:00
livepatch Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
locking exec: Transform exec_update_mutex into a rw_semaphore 2021-04-12 12:51:05 +08:00
power PM: hibernate: remove the bogus call to get_gendisk() in software_resume() 2021-03-16 16:39:16 +08:00
printk printk: handle blank console arguments passed in. 2021-03-16 16:37:21 +08:00
rcu arm64: smp: Tell RCU about CPUs that fail to come online 2021-03-16 16:41:11 +08:00
sched sched/fair: Check for idle core in wake_affine 2021-03-18 06:25:56 +00:00
time tick/sched: Remove bogus boot "safety" check 2021-03-16 16:43:56 +08:00
tkernel Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
trace Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" 2021-03-16 16:43:47 +08:00
.gitignore Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig.freezer Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig.hz Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig.locks Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig.preempt Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Makefile kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() 2021-03-16 16:36:31 +08:00
acct.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
async.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
audit.c audit: fix a net reference leak in audit_list_rules_send() 2021-03-16 16:29:25 +08:00
audit.h audit: fix a net reference leak in audit_list_rules_send() 2021-03-16 16:29:25 +08:00
audit_fsnotify.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
audit_tree.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
audit_watch.c audit: CONFIG_CHANGE don't log internal bookkeeping as an event 2021-03-16 16:36:51 +08:00
auditfilter.c audit: fix a net reference leak in audit_list_rules_send() 2021-03-16 16:29:25 +08:00
auditsc.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
backtracetest.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
bounds.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
capability.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
compat.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
configs.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
context_tracking.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
cpu.c kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling 2021-03-16 16:42:28 +08:00
cpu_pm.c kernel/cpu_pm: Fix uninitted local in cpu_pm 2021-03-16 16:29:48 +08:00
crash_core.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
crash_dump.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
cred.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
delayacct.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
dma.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
elfcore.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
exec_domain.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
exit.c don't dump the threads that had been already exiting when zapped. 2021-03-16 16:40:57 +08:00
extable.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
fail_function.c fail_function: Remove a redundant mutex unlock 2021-03-16 16:41:23 +08:00
fork.c exec: Transform exec_update_mutex into a rw_semaphore 2021-04-12 12:51:05 +08:00
freezer.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
futex.c futex: Don't enable IRQs unconditionally in put_pi_state() 2021-03-16 16:40:54 +08:00
gen_kheaders.sh kbuild: add variables for compression tools 2021-03-16 16:35:19 +08:00
groups.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
hung_task.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
iomem.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
irq_work.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
jump_label.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kallsyms.c kallsyms: Refactor kallsyms_show_value() to take cred 2021-03-16 16:31:37 +08:00
kcmp.c exec: Transform exec_update_mutex into a rw_semaphore 2021-04-12 12:51:05 +08:00
kcov.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec_core.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec_elf.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec_file.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec_internal.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kheaders.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kmod.c kmod: make request_module() return an error when autoloading is disabled 2021-03-16 16:26:15 +08:00
kprobes.c kprobes: Fix compiler warning for !CONFIG_KPROBES_ON_FTRACE 2021-03-16 16:37:41 +08:00
ksysfs.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kthread.c kthread_worker: prevent queuing delayed work from timer_fn when it is being canceled 2021-03-16 16:40:21 +08:00
latencytop.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
module-internal.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
module.c module: delay kobject uevent until after module init call 2021-03-16 16:43:55 +08:00
module_signature.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
module_signing.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
notifier.c kernel/notifier.c: intercept duplicate registrations to avoid infinite loops 2021-03-16 16:36:43 +08:00
nsproxy.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
padata.c padata: add separate cpuhp node for CPUHP_PADATA_DEAD 2021-03-16 16:28:57 +08:00
panic.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
params.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
pid.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
pid_namespace.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
profile.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
ptrace.c ptrace: Set PF_SUPERPRIV when checking capability 2021-03-16 16:41:32 +08:00
range.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
reboot.c reboot: fix overflow parsing reboot cpu number 2021-03-16 16:40:55 +08:00
relay.c kernel/relay.c: fix memleak on destroy relay channel 2021-03-16 16:34:28 +08:00
resource.c /dev/mem: Revoke mappings when a driver claims the region 2021-03-16 16:30:25 +08:00
rseq.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
seccomp.c seccomp: Set PF_SUPERPRIV when checking capability 2021-03-16 16:41:32 +08:00
signal.c ptrace: fix task_join_group_stop() for the case when current is traced 2021-03-16 16:40:18 +08:00
smp.c smp: introduce a new interface smp_call_function_many_async 2021-03-18 06:25:56 +00:00
smpboot.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
smpboot.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
softirq.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
stackleak.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
stacktrace.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
stop_machine.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sys.c kernel/sys.c: avoid copying possible padding bytes in copy_to_user 2021-03-16 16:36:43 +08:00
sys_ni.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sysctl-test.c kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() 2021-03-16 16:36:31 +08:00
sysctl.c net: rps using pvipi 2021-03-19 08:24:58 +00:00
sysctl_binary.c net: change TCP_TIMEWAIT_LEN on runtime 2021-03-16 16:43:58 +08:00
task_work.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
taskstats.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
test_kprobes.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
torture.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
tracepoint.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
tsacct.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
ucount.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
uid16.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
uid16.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
umh.c usermodehelper: reset umask to default before executing user process 2021-03-16 16:37:54 +08:00
up.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
user-return-notifier.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
user.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
user_namespace.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
utsname.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
utsname_sysctl.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
watchdog.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
watchdog_hld.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
workqueue.c workqueue: Remove the warning in wq_worker_sleeping() 2021-03-16 16:37:11 +08:00
workqueue_internal.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00