kernel_samsung_a53x/kernel
Aleksandr Nogikh 2bb4b1321d kcov: don't lose track of remote references during softirqs
commit 01c8f9806bde438ca1c8cbbc439f0a14a6694f6c upstream.

In kcov_remote_start()/kcov_remote_stop(), we swap the previous KCOV
metadata of the current task into a per-CPU variable.  However, the
kcov_mode_enabled(mode) check is not sufficient in the case of remote KCOV
coverage: current->kcov_mode always remains KCOV_MODE_DISABLED for remote
KCOV objects.

If the original task that has invoked the KCOV_REMOTE_ENABLE ioctl happens
to get interrupted and kcov_remote_start() is called, it ultimately leads
to kcov_remote_stop() NOT restoring the original KCOV reference.  So when
the task exits, all registered remote KCOV handles remain active forever.

The most uncomfortable effect (at least for syzkaller) is that the bug
prevents the reuse of the same /sys/kernel/debug/kcov descriptor.  If
we obtain it in the parent process and then e.g.  drop some
capabilities and continuously fork to execute individual programs, at
some point current->kcov of the forked process is lost,
kcov_task_exit() takes no action, and all KCOV_REMOTE_ENABLE ioctls
calls from subsequent forks fail.

And, yes, the efficiency is also affected if we keep on losing remote
kcov objects.
a) kcov_remote_map keeps on growing forever.
b) (If I'm not mistaken), we're also not freeing the memory referenced
by kcov->area.

Fix it by introducing a special kcov_mode that is assigned to the task
that owns a KCOV remote object.  It makes kcov_mode_enabled() return true
and yet does not trigger coverage collection in __sanitizer_cov_trace_pc()
and write_comp_data().

[nogikh@google.com: replace WRITE_ONCE() with an ordinary assignment]
  Link: https://lkml.kernel.org/r/20240614171221.2837584-1-nogikh@google.com
Link: https://lkml.kernel.org/r/20240611133229.527822-1-nogikh@google.com
Fixes: 5ff3b30ab57d ("kcov: collect coverage from interrupts")
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marco Elver <elver@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 14:19:10 +01:00
..
bpf Revert "fs: add file and path permissions helpers" 2024-11-19 13:30:21 +01:00
cgroup sched/fair: Allow disabling sched_balance_newidle with sched_relax_domain_level 2024-11-19 12:27:00 +01:00
configs Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
debug kdb: Use format-specifiers rather than memset() for padding in kdb_read() 2024-11-19 12:27:19 +01:00
dma dma-mapping: clear dev->dma_mem to NULL after freeing it 2024-11-18 12:12:37 +01:00
entry Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
events perf/core: Fix reentry problem in perf_output_read_group() 2024-11-19 09:22:41 +01:00
futex futex: Don't include process MM in futex key on no-MMU 2024-11-18 11:42:47 +01:00
gcov gcov: add support for GCC 14 2024-11-19 14:19:10 +01:00
irq genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline 2024-11-19 12:27:11 +01:00
kcsan Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
livepatch kallsyms: refactor {,module_}kallsyms_on_each_symbol 2024-11-19 12:27:32 +01:00
locking lockdep: Fix block chain corruption 2024-11-18 12:10:56 +01:00
power PM: suspend: Set mem_sleep_current during kernel command line setup 2024-11-19 09:22:17 +01:00
printk printk: Update @console_may_schedule in console_trylock_spinning() 2024-11-19 09:22:40 +01:00
rcu rcutorture: Fix invalid context warning when enable srcu barrier testing 2024-11-19 14:19:06 +01:00
sched sched/fair: Allow disabling sched_balance_newidle with sched_relax_domain_level 2024-11-19 12:27:00 +01:00
time tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device() 2024-11-19 14:19:05 +01:00
trace tracing: Build event generation tests only as modules 2024-11-19 14:19:07 +01:00
acct.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
async.c async: Introduce async_schedule_dev_nocall() 2024-11-18 12:12:56 +01:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-11-18 12:13:09 +01:00
audit.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
audit_fsnotify.c fsnotify: make allow_dups a property of the group 2024-11-19 12:27:55 +01:00
audit_tree.c fsnotify: pass flags argument to fsnotify_alloc_group() 2024-11-19 12:27:55 +01:00
audit_watch.c fsnotify: pass flags argument to fsnotify_alloc_group() 2024-11-19 12:27:55 +01:00
auditfilter.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
auditsc.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
backtracetest.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
bounds.c bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS 2024-11-19 11:32:40 +01:00
capability.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
cfi.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
compat.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
configs.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
context_tracking.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
cpu.c cpu: Re-enable CPU mitigations by default for !X86 architectures 2024-11-19 11:32:38 +01:00
cpu_pm.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
crash_core.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
crash_dump.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
cred.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
delayacct.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
dma.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
exec_domain.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
exit.c security: samsung: defex_lsm: nuke 2024-06-15 16:20:49 -03:00
extable.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
fail_function.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
fork.c exec: Simplify unshare_files 2024-11-19 12:27:27 +01:00
freezer.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
gen_kheaders.sh Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
groups.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
hung_task.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
iomem.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
irq_work.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
jump_label.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kallsyms.c kallsyms: only build {,module_}kallsyms_on_each_symbol when required 2024-11-19 12:27:33 +01:00
kcmp.c kcmp: In get_file_raw_ptr use task_lookup_fd_rcu 2024-11-19 12:27:27 +01:00
Kconfig.freezer Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Kconfig.hz Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Kconfig.locks Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Kconfig.preempt Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kcov.c kcov: don't lose track of remote references during softirqs 2024-11-19 14:19:10 +01:00
kexec.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_core.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_elf.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_file.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kexec_internal.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kheaders.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kmod.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kprobes.c kprobes: Fix possible use-after-free issue on kprobe registration 2024-11-19 11:32:21 +01:00
ksysfs.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
kthread.c exit: Implement kthread_exit 2024-11-19 12:27:49 +01:00
latencytop.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
Makefile kernel: Use the stock defconfig for /proc/config.gz 2024-06-15 16:20:14 -03:00
module-internal.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
module.c NFSD: Remove svc_serv_ops::svo_module 2024-11-19 12:27:54 +01:00
module_signature.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
module_signing.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
notifier.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
nsproxy.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
padata.c padata: Disable BH when taking works lock on MT path 2024-11-19 14:19:06 +01:00
panic.c panic: Flush kernel log buffer at the end 2024-11-19 09:23:11 +01:00
params.c params: lift param_set_uint_minmax to common code 2024-11-19 12:27:09 +01:00
pid.c kernel/pid.c: implement additional checks upon pidfd_create() parameters 2024-11-19 12:27:43 +01:00
pid_namespace.c zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING 2024-11-19 14:19:05 +01:00
profile.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
ptrace.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
range.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2024-11-18 11:43:25 +01:00
regset.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
relay.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
resource.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
rseq.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
scftorture.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
scs.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2024-11-18 22:25:35 +01:00
signal.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
smp.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
smpboot.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
smpboot.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
softirq.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
stackleak.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
stacktrace.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
static_call.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
stop_machine.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
sys.c Revert "fs: add file and path permissions helpers" 2024-11-19 13:30:21 +01:00
sys_ni.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
sysctl-test.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
sysctl.c sysctl: introduce new proc handler proc_dobool 2024-11-19 12:27:44 +01:00
task_work.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
taskstats.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
test_kprobes.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
torture.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
tracepoint.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
tsacct.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
ucount.c fanotify: configurable limits via sysfs 2024-11-19 12:27:37 +01:00
uid16.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
uid16.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
umh.c security: samsung: defex_lsm: nuke 2024-06-15 16:20:49 -03:00
up.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
user-return-notifier.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
user.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
user_namespace.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
usermode_driver.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
utsname.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
utsname_sysctl.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
watch_queue.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
watchdog.c watchdog: move softlockup_panic back to early_param 2024-11-18 11:43:21 +01:00
watchdog_hld.c Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00
workqueue.c Revert "workqueue: remove unused cancel_work()" 2024-11-18 12:11:11 +01:00
workqueue_internal.h Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00