linux/kernel
Stephen Brennan ae0d1ea3e8 kprobe/ftrace: bail out if ftrace was killed
[ Upstream commit 1a7d0890dd ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27 13:49:03 +02:00
..
bpf bpf: Fix a potential use-after-free in bpf_link_free() 2024-06-21 14:38:15 +02:00
cgroup sched/fair: Allow disabling sched_balance_newidle with sched_relax_domain_level 2024-06-12 11:12:13 +02:00
configs Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
debug kdb: Use format-specifiers rather than memset() for padding in kdb_read() 2024-06-16 13:47:44 +02:00
dma swiotlb: extend buffer pre-padding to alloc_align_mask if necessary 2024-06-21 14:38:46 +02:00
entry entry: Respect changes to system call number by trace_sys_enter() 2024-04-03 15:28:50 +02:00
events perf/core: Fix missing wakeup when waiting for context reference 2024-06-21 14:38:39 +02:00
futex futex: Don't include process MM in futex key on no-MMU 2023-11-20 11:58:53 +01:00
gcov gcov: shut up missing prototype warnings for internal stubs 2023-08-18 10:18:58 -07:00
irq genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after() 2024-06-16 13:47:46 +02:00
kcsan kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures 2023-06-09 23:29:50 +10:00
livepatch livepatch: Fix missing newline character in klp_resolve_symbols() 2023-11-20 11:59:25 +01:00
locking lockdep: Fix block chain corruption 2023-12-03 07:33:06 +01:00
module modules: wait do_free_init correctly 2024-03-26 18:19:55 -04:00
power PM: s2idle: Make sure CPUs will wakeup directly on resume 2024-04-17 11:19:26 +02:00
printk printk: For @suppress_panic_printk check for other CPU in panic 2024-04-13 13:07:29 +02:00
rcu rcutorture: Fix invalid context warning when enable srcu barrier testing 2024-06-27 13:49:01 +02:00
sched sched/core: Fix incorrect initialization of the 'burst' parameter in cpu_max_write() 2024-06-12 11:12:13 +02:00
time tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device() 2024-06-21 14:38:46 +02:00
trace kprobe/ftrace: bail out if ftrace was killed 2024-06-27 13:49:03 +02:00
.gitignore
acct.c audit/stable-6.6 PR 20230829 2023-08-30 08:17:35 -07:00
async.c async: Introduce async_schedule_dev_nocall() 2024-01-31 16:18:49 -08:00
audit_fsnotify.c
audit_tree.c
audit_watch.c audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare() 2023-11-28 17:19:56 +00:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-02-05 20:14:14 +00:00
audit.h audit: correct audit_filter_inodes() definition 2023-07-21 12:17:25 -04:00
auditfilter.c audit: move trailing statements to next line 2023-08-15 18:16:14 -04:00
auditsc.c audit,io_uring: io_uring openat triggers audit reference count underflow 2023-10-13 18:34:46 +02:00
backtracetest.c
bounds.c bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS 2024-05-02 16:32:50 +02:00
capability.c lsm: constify the 'target' parameter in security_capget() 2023-08-08 16:48:47 -04:00
cfi.c
compat.c
configs.c
context_tracking.c locking/atomic: treewide: use raw_atomic*_<op>() 2023-06-05 09:57:20 +02:00
cpu_pm.c
cpu.c cpu: Ignore "mitigations" kernel parameter if CPU_MITIGATIONS=n 2024-06-12 11:11:24 +02:00
crash_core.c mm: turn folio_test_hugetlb into a PageType 2024-05-02 16:32:47 +02:00
crash_dump.c
cred.c cred: get rid of CONFIG_DEBUG_CREDENTIALS 2023-12-20 17:01:51 +01:00
delayacct.c delayacct: track delays from IRQ/SOFTIRQ 2023-04-18 16:39:34 -07:00
dma.c
exec_domain.c
exit.c cred: get rid of CONFIG_DEBUG_CREDENTIALS 2023-12-20 17:01:51 +01:00
extable.c
fail_function.c
fork.c Revert "fork: defer linking file vma until vma is fully initialized" 2024-06-21 14:38:47 +02:00
freezer.c
gen_kheaders.sh kheaders: explicitly define file modes for archived headers 2024-06-21 14:38:40 +02:00
groups.c
hung_task.c kernel/hung_task.c: set some hung_task.c variables storage-class-specifier to static 2023-04-08 13:45:37 -07:00
iomem.c kernel/iomem.c: remove __weak ioremap_cache helper 2023-08-21 13:37:28 -07:00
irq_work.c
jump_label.c
kallsyms_internal.h
kallsyms_selftest.c Modules changes for v6.6-rc1 2023-08-29 17:32:32 -07:00
kallsyms_selftest.h
kallsyms.c kallsyms: Change func signature for cleanup_symbol_name() 2023-08-25 15:00:36 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.kexec kexec: select CRYPTO from KEXEC_FILE instead of depending on it 2024-01-05 15:19:41 +01:00
Kconfig.locks
Kconfig.preempt
kcov.c kcov: add prototypes for helper functions 2023-06-09 17:44:17 -07:00
kexec_core.c kexec: do syscore_shutdown() in kernel_kexec 2024-01-31 16:18:56 -08:00
kexec_elf.c
kexec_file.c integrity-v6.6 2023-08-30 09:16:56 -07:00
kexec_internal.h
kexec.c kernel: kexec: copy user-array safely 2023-11-28 17:19:40 +00:00
kheaders.c
kprobes.c kprobe/ftrace: bail out if ftrace was killed 2024-06-27 13:49:03 +02:00
ksyms_common.c kallsyms: make kallsyms_show_value() as generic function 2023-06-08 12:27:20 -07:00
ksysfs.c crash: hotplug support for kexec_load() 2023-08-24 16:25:14 -07:00
kthread.c kthread: add kthread_stop_put 2024-06-12 11:12:52 +02:00
latencytop.c
Makefile kernel/numa.c: Move logging out of numa.h 2024-06-12 11:11:50 +02:00
module_signature.c
notifier.c notifiers: add tracepoints to the notifiers infrastructure 2023-04-08 13:45:38 -07:00
nsproxy.c nsproxy: Convert nsproxy.count to refcount_t 2023-08-21 11:29:12 -07:00
numa.c kernel/numa.c: Move logging out of numa.h 2024-06-12 11:11:50 +02:00
padata.c padata: Disable BH when taking works lock on MT path 2024-06-27 13:49:00 +02:00
panic.c panic: Flush kernel log buffer at the end 2024-04-13 13:07:29 +02:00
params.c kernel: params: Remove unnecessary ‘0’ values from err 2023-07-10 12:47:01 -07:00
pid_namespace.c zap_pid_ns_processes: clear TIF_NOTIFY_SIGNAL along with TIF_SIGPENDING 2024-06-21 14:38:50 +02:00
pid_sysctl.h memfd: replace ratcheting feature from vm.memfd_noexec with hierarchy 2023-08-21 13:37:59 -07:00
pid.c pidfd: prevent a kernel-doc warning 2023-09-19 13:21:33 -07:00
profile.c
ptrace.c ptrace: Provide set/get interface for syscall user dispatch 2023-04-16 14:23:07 +02:00
range.c
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2023-11-28 17:20:04 +00:00
regset.c
relay.c kernel: relay: remove unnecessary NULL values from relay_open_buf 2023-08-18 10:18:55 -07:00
resource_kunit.c
resource.c kernel/resource: Increment by align value in get_free_mem_region() 2024-01-10 17:16:58 +01:00
rseq.c
scftorture.c scftorture: Pause testing after memory-allocation failure 2023-07-14 15:02:57 -07:00
scs.c
seccomp.c seccomp: Add missing kerndoc notations 2023-08-17 12:32:15 -07:00
signal.c signal: print comm and exe name on fatal signals 2023-08-18 10:18:50 -07:00
smp.c smp,csd: Throw an error if a CSD lock is stuck for too long 2023-11-28 17:19:36 +00:00
smpboot.c kthread: add kthread_stop_put 2024-06-12 11:12:52 +02:00
smpboot.h
softirq.c softirq: Fix suspicious RCU usage in __do_softirq() 2024-06-12 11:11:27 +02:00
stackleak.c stackleak: allow to specify arch specific stackleak poison function 2023-04-20 11:36:35 +02:00
stacktrace.c
static_call_inline.c
static_call.c
stop_machine.c
sys_ni.c posix-timers: Get rid of [COMPAT_]SYS_NI() uses 2024-01-20 11:51:46 +01:00
sys.c prctl: generalize PR_SET_MDWE support check to be per-arch 2024-04-03 15:28:54 +02:00
sysctl-test.c
sysctl.c v6.5-rc1-sysctl-next 2023-06-28 16:05:21 -07:00
task_work.c task_work: add kerneldoc annotation for 'data' argument 2023-09-19 13:21:32 -07:00
taskstats.c
torture.c rcutorture: Fix stuttering races and other issues 2023-11-28 17:20:08 +00:00
tracepoint.c
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
user_namespace.c
user-return-notifier.c
user.c
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
watch_queue.c kernel: watch_queue: copy user-array safely 2023-11-28 17:19:40 +00:00
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: move softlockup_panic back to early_param 2023-11-28 17:19:57 +00:00
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 workqueue: Fix selection of wake_cpu in kick_pool() 2024-05-17 12:02:31 +02:00