linux/kernel
Stephen Brennan 1a7d0890dd kprobe/ftrace: bail out if ftrace was killed
If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, the ftrace_ops associated with the kprobes will be
freed, yet the kprobes will still be active, and when triggered, they
will use the freed memory, likely resulting in a page fault and panic.

This behavior can be reproduced quite easily, by creating a kprobe and
then triggering a ftrace_kill(). For simplicity, we can simulate an
ftrace error with a kernel module like [1]:

[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer

  sudo perf probe --add commit_creds
  sudo perf trace -e probe:commit_creds
  # In another terminal
  make
  sudo insmod ftrace_killer.ko  # calls ftrace_kill(), simulating bug
  # Back to perf terminal
  # ctrl-c
  sudo perf probe --del commit_creds

After a short period, a page fault and panic would occur as the kprobe
continues to execute and uses the freed ftrace_ops. While ftrace_kill()
is supposed to be used only in extreme circumstances, it is invoked in
FTRACE_WARN_ON() and so there are many places where an unexpected bug
could be triggered, yet the system may continue operating, possibly
without the administrator noticing. If ftrace_kill() does not panic the
system, then we should do everything we can to continue operating,
rather than leave a ticking time bomb.

Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/

Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-16 07:23:30 +09:00
..
bpf Including fixes from netfilter, bluetooth and bpf. 2024-04-04 14:49:10 -07:00
cgroup Networking changes for 6.9. 2024-03-12 17:44:08 -07:00
configs configs/hardening: Disable CONFIG_UBSAN_SIGNED_WRAP 2024-04-15 11:08:24 -07:00
debug kdb: Fix a potential buffer overflow in kdb_local() 2024-01-17 17:19:06 +00:00
dma swiotlb: do not set total_used to 0 in swiotlb_create_debugfs_files() 2024-04-02 17:08:09 +02:00
entry entry: Respect changes to system call number by trace_sys_enter() 2024-03-12 13:23:32 +01:00
events uprobes: reduce contention on uprobes_tree access 2024-05-01 23:18:47 +09:00
futex futex: Prevent the reuse of stale pi_state 2024-01-19 12:58:17 +01:00
gcov gcov: annotate struct gcov_iterator with __counted_by 2023-10-18 14:43:22 -07:00
irq genirq: Introduce IRQF_COND_ONESHOT and use it in pinctrl-amd 2024-03-25 23:45:21 +01:00
kcsan mm: delete checks for xor_unlock_is_negative_byte() 2023-10-18 14:34:17 -07:00
livepatch livepatch: Fix missing newline character in klp_resolve_symbols() 2023-09-20 11:24:18 +02:00
locking locking/rtmutex: Use try_cmpxchg_relaxed() in mark_rt_mutex_waiters() 2024-03-01 13:02:05 +01:00
module This push fixes a regression that broke iwd as well as a divide by 2024-03-25 10:48:23 -07:00
power PM: s2idle: Make sure CPUs will wakeup directly on resume 2024-04-08 15:36:54 +02:00
printk printk changes for 6.9-rc2 2024-03-26 09:25:57 -07:00
rcu Merge branches 'rcu-doc.2024.02.14a', 'rcu-nocb.2024.02.14a', 'rcu-exp.2024.02.14a', 'rcu-tasks.2024.02.26a' and 'rcu-misc.2024.02.14a' into rcu.2024.02.26a 2024-02-26 17:37:25 -08:00
sched sched/isolation: Fix boot crash when maxcpus < first housekeeping CPU 2024-04-28 10:08:21 +02:00
time timekeeping: Use READ/WRITE_ONCE() for tick_do_timer_cpu 2024-04-10 10:13:42 +02:00
trace kprobe/ftrace: bail out if ftrace was killed 2024-05-16 07:23:30 +09:00
.gitignore
acct.c fs: rename __mnt_{want,drop}_write*() helpers 2023-09-11 15:05:50 +02:00
async.c async: Use a dedicated unbound workqueue with raised min_active 2024-02-09 11:13:59 -10:00
audit_fsnotify.c
audit_tree.c As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
audit_watch.c audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare() 2023-11-14 17:34:27 -05:00
audit.c audit: use KMEM_CACHE() instead of kmem_cache_create() 2024-01-25 10:12:22 -05:00
audit.h audit: correct audit_filter_inodes() definition 2023-07-21 12:17:25 -04:00
auditfilter.c audit: remove unnecessary assignment in audit_dupe_lsm_field() 2024-01-25 09:59:27 -05:00
auditsc.c audit,io_uring: io_uring openat triggers audit reference count underflow 2023-10-13 18:34:46 +02:00
backtracetest.c backtracetest: Convert from tasklet to BH workqueue 2024-02-05 13:22:34 -10:00
bounds.c bounds: support non-power-of-two CONFIG_NR_CPUS 2024-02-22 15:38:51 -08:00
capability.c lsm: constify the 'target' parameter in security_capget() 2023-08-08 16:48:47 -04:00
cfi.c
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-03-14 19:32:38 -07:00
configs.c
context_tracking.c context_tracking: Fix kerneldoc headers for __ct_user_{enter,exit}() 2024-02-14 07:53:50 -08:00
cpu_pm.c
cpu.c cpu: Ignore "mitigations" kernel parameter if CPU_MITIGATIONS=n 2024-04-25 15:47:39 +02:00
crash_core.c crash: split crash dumping code out from kexec_core.c 2024-02-23 17:48:22 -08:00
crash_reserve.c crash: use macro to add crashk_res into iomem early for specific arch 2024-03-26 11:14:12 -07:00
cred.c cred: Use KMEM_CACHE() instead of kmem_cache_create() 2024-02-23 17:33:31 -05:00
delayacct.c delayacct: track delays from IRQ/SOFTIRQ 2023-04-18 16:39:34 -07:00
dma.c
elfcorehdr.c crash: remove dependency of FA_DUMP on CRASH_DUMP 2024-02-23 17:48:22 -08:00
exec_domain.c
exit.c vfs-6.9.pidfd 2024-03-11 10:21:06 -07:00
exit.h exit: add internal include file with helpers 2023-09-21 12:03:50 -06:00
extable.c
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-02-08 13:36:22 +01:00
fork.c fork: defer linking file vma until vma is fully initialized 2024-04-16 15:39:51 -07:00
freezer.c Linux 6.7-rc6 2023-12-23 15:52:13 +01:00
gen_kheaders.sh Revert "kheaders: substituting --sort in archive creation" 2023-05-28 16:20:21 +09:00
groups.c groups: Convert group_info.usage to refcount_t 2023-09-29 11:28:39 -07:00
hung_task.c kernel/hung_task.c: export sysctl_hung_task_timeout_secs 2024-03-13 21:22:04 -04:00
iomem.c kernel/iomem.c: remove __weak ioremap_cache helper 2023-08-21 13:37:28 -07:00
irq_work.c trace: Add trace_ipi_send_cpu() 2023-03-24 11:01:29 +01:00
jump_label.c
kallsyms_internal.h
kallsyms_selftest.c mm/vmalloc: remove vmap_area_list 2024-02-23 17:48:19 -08:00
kallsyms_selftest.h
kallsyms.c kallsyms: Change func signature for cleanup_symbol_name() 2023-08-25 15:00:36 -07:00
kcmp.c file: convert to SLAB_TYPESAFE_BY_RCU 2023-10-19 11:02:48 +02:00
Kconfig.freezer
Kconfig.hz
Kconfig.kexec crash: clean up kdump related config items 2024-02-23 17:48:22 -08:00
Kconfig.locks
Kconfig.preempt
kcov.c kcov: add prototypes for helper functions 2023-06-09 17:44:17 -07:00
kexec_core.c - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min 2024-03-14 18:03:09 -07:00
kexec_elf.c
kexec_file.c arm64, crash: wrap crash dumping code into crash related ifdefs 2024-02-23 17:48:23 -08:00
kexec_internal.h crash: remove dependency of FA_DUMP on CRASH_DUMP 2024-02-23 17:48:22 -08:00
kexec.c crash: split crash dumping code out from kexec_core.c 2024-02-23 17:48:22 -08:00
kheaders.c kheaders: Use array declaration instead of char 2023-03-24 20:10:59 -07:00
kprobes.c kprobe/ftrace: bail out if ftrace was killed 2024-05-16 07:23:30 +09:00
ksyms_common.c kallsyms: make kallsyms_show_value() as generic function 2023-06-08 12:27:20 -07:00
ksysfs.c Driver core changes for 6.9-rc1 2024-03-21 13:34:15 -07:00
kthread.c As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
latencytop.c
Makefile crash: split crash dumping code out from kexec_core.c 2024-02-23 17:48:22 -08:00
module_signature.c
notifier.c notifiers: add tracepoints to the notifiers infrastructure 2023-04-08 13:45:38 -07:00
nsproxy.c pidfd: add pidfs 2024-03-01 12:23:37 +01:00
numa.c kernel/numa.c: Move logging out of numa.h 2023-12-20 19:26:30 -05:00
padata.c Author: Gang Li padata: dispatch works on 2024-03-06 13:04:17 -08:00
panic.c - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min 2024-03-14 18:03:09 -07:00
params.c params: Fix multi-line comment style 2023-12-01 09:51:44 -08:00
pid_namespace.c wait: Remove uapi header file from main header file 2023-12-20 19:26:31 -05:00
pid_sysctl.h memfd: replace ratcheting feature from vm.memfd_noexec with hierarchy 2023-08-21 13:37:59 -07:00
pid.c pidfs: remove config option 2024-03-13 12:53:53 -07:00
profile.c profiling: Remove create_prof_cpu_mask(). 2024-04-27 11:17:48 -07:00
ptrace.c ptrace_attach: shift send(SIGSTOP) into ptrace_set_stopped() 2024-02-22 15:38:52 -08:00
range.c
reboot.c Thermal control updates for 6.8-rc1 2024-01-09 16:20:17 -08:00
regset.c
relay.c kernel: relay: remove relay_file_splice_read dead code, doesn't work 2023-12-29 12:22:27 -08:00
resource_kunit.c
resource.c Quite a lot of kexec work this time around. Many singleton patches in 2024-01-09 11:46:20 -08:00
rseq.c
scftorture.c scftorture: Pause testing after memory-allocation failure 2023-07-14 15:02:57 -07:00
scs.c
seccomp.c file: remove __receive_fd() 2023-12-12 14:24:14 +01:00
signal.c - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min 2024-03-14 18:03:09 -07:00
smp.c CSD lock commits for v6.7 2023-10-30 17:56:53 -10:00
smpboot.c kthread: add kthread_stop_put 2023-10-04 10:41:57 -07:00
smpboot.h
softirq.c workqueue: Drain BH work items on hot-unplugged CPUs 2024-02-29 11:51:24 -10:00
stackleak.c stackleak: allow to specify arch specific stackleak poison function 2023-04-20 11:36:35 +02:00
stacktrace.c stacktrace: fix kernel-doc typo 2023-12-29 12:22:29 -08:00
static_call_inline.c
static_call.c
stop_machine.c
sys_ni.c lsm/stable-6.8 PR 20240105 2024-01-09 12:57:46 -08:00
sys.c prctl: generalize PR_SET_MDWE support check to be per-arch 2024-03-26 11:07:22 -07:00
sysctl-test.c
sysctl.c tracing: Support to dump instance traces by ftrace_dump_on_oops 2024-03-18 10:33:06 -04:00
task_work.c task_work: add kerneldoc annotation for 'data' argument 2023-09-19 13:21:32 -07:00
taskstats.c taskstats: fill_stats_for_tgid: use for_each_thread() 2023-10-04 10:41:57 -07:00
torture.c torture: Print out torture module parameters 2023-09-24 17:24:01 +02:00
tracepoint.c tracepoint: Allow livepatch module add trace event 2023-02-18 14:34:36 -05:00
tsacct.c
ucount.c sysctl: Add size to register_sysctl 2023-08-15 15:26:17 -07:00
uid16.c
uid16.h
umh.c sysctl: fix unused proc_cap_handler() function warning 2023-06-29 15:19:43 -07:00
up.c smp: Change function signatures to use call_single_data_t 2023-09-13 14:59:24 +02:00
user_namespace.c user_namespace: remove unnecessary NULL values from kbuf 2024-02-22 15:38:52 -08:00
user-return-notifier.c
user.c binfmt_misc: enable sandboxed mounts 2023-10-11 08:46:01 -07:00
usermode_driver.c
utsname_sysctl.c utsname: simplify one-level sysctl registration for uts_kern_table 2023-04-13 11:49:35 -07:00
utsname.c
vhost_task.c vhost: Fix worker hangs due to missed wake up calls 2023-06-08 15:43:09 -04:00
vmcore_info.c mm: turn folio_test_hugetlb into a PageType 2024-04-24 19:34:26 -07:00
watch_queue.c watch_queue: fix kcalloc() arguments order 2023-12-21 13:17:54 +01:00
watchdog_buddy.c watchdog/hardlockup: move SMP barriers from common code to buddy code 2023-06-19 16:25:28 -07:00
watchdog_perf.c watchdog/perf: add a weak function for an arch to detect if perf can use NMIs 2023-06-09 17:44:21 -07:00
watchdog.c watchdog/core: remove sysctl handlers from public header 2024-03-12 13:09:23 -07:00
workqueue_internal.h workqueue: Drop the special locking rule for worker->flags and worker_pool->flags 2023-08-07 15:57:22 -10:00
workqueue.c Driver core changes for 6.9-rc1 2024-03-21 13:34:15 -07:00