linux-stable/kernel
Kuniyuki Iwashima 19cd630712 kprobes: don't call disarm_kprobe() for disabled kprobes
commit 9c80e79906 upstream.

The assumption in __disable_kprobe() is wrong, and it could try to disarm
an already disarmed kprobe and fire the WARN_ONCE() below. [0]  We can
easily reproduce this issue.

1. Write 0 to /sys/kernel/debug/kprobes/enabled.

  # echo 0 > /sys/kernel/debug/kprobes/enabled

2. Run execsnoop.  At this time, one kprobe is disabled.

  # /usr/share/bcc/tools/execsnoop &
  [1] 2460
  PCOMM            PID    PPID   RET ARGS

  # cat /sys/kernel/debug/kprobes/list
  ffffffff91345650  r  __x64_sys_execve+0x0    [FTRACE]
  ffffffff91345650  k  __x64_sys_execve+0x0    [DISABLED][FTRACE]

3. Write 1 to /sys/kernel/debug/kprobes/enabled, which changes
   kprobes_all_disarmed to false but does not arm the disabled kprobe.

  # echo 1 > /sys/kernel/debug/kprobes/enabled

  # cat /sys/kernel/debug/kprobes/list
  ffffffff91345650  r  __x64_sys_execve+0x0    [FTRACE]
  ffffffff91345650  k  __x64_sys_execve+0x0    [DISABLED][FTRACE]

4. Kill execsnoop, when __disable_kprobe() calls disarm_kprobe() for the
   disabled kprobe and hits the WARN_ONCE() in __disarm_kprobe_ftrace().

  # fg
  /usr/share/bcc/tools/execsnoop
  ^C

Actually, WARN_ONCE() is fired twice, and __unregister_kprobe_top() misses
some cleanups and leaves the aggregated kprobe in the hash table.  Then,
__unregister_trace_kprobe() initialises tk->rp.kp.list and creates an
infinite loop like this.

  aggregated kprobe.list -> kprobe.list -.
                                     ^    |
                                     '.__.'

In this situation, these commands fall into the infinite loop and result
in RCU stall or soft lockup.

  cat /sys/kernel/debug/kprobes/list : show_kprobe_addr() enters into the
                                       infinite loop with RCU.

  /usr/share/bcc/tools/execsnoop : warn_kprobe_rereg() holds kprobe_mutex,
                                   and __get_valid_kprobe() is stuck in
				   the loop.

To avoid the issue, make sure we don't call disarm_kprobe() for disabled
kprobes.

[0]
Failed to disarm kprobe-ftrace at __x64_sys_execve+0x0/0x40 (error -2)
WARNING: CPU: 6 PID: 2460 at kernel/kprobes.c:1130 __disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129)
Modules linked in: ena
CPU: 6 PID: 2460 Comm: execsnoop Not tainted 5.19.0+ #28
Hardware name: Amazon EC2 c5.2xlarge/, BIOS 1.0 10/16/2017
RIP: 0010:__disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129)
Code: 24 8b 02 eb c1 80 3d c4 83 f2 01 00 75 d4 48 8b 75 00 89 c2 48 c7 c7 90 fa 0f 92 89 04 24 c6 05 ab 83 01 e8 e4 94 f0 ff <0f> 0b 8b 04 24 eb b1 89 c6 48 c7 c7 60 fa 0f 92 89 04 24 e8 cc 94
RSP: 0018:ffff9e6ec154bd98 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffffff930f7b00 RCX: 0000000000000001
RDX: 0000000080000001 RSI: ffffffff921461c5 RDI: 00000000ffffffff
RBP: ffff89c504286da8 R08: 0000000000000000 R09: c0000000fffeffff
R10: 0000000000000000 R11: ffff9e6ec154bc28 R12: ffff89c502394e40
R13: ffff89c502394c00 R14: ffff9e6ec154bc00 R15: 0000000000000000
FS:  00007fe800398740(0000) GS:ffff89c812d80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00057f010 CR3: 0000000103b54006 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
 __disable_kprobe (kernel/kprobes.c:1716)
 disable_kprobe (kernel/kprobes.c:2392)
 __disable_trace_kprobe (kernel/trace/trace_kprobe.c:340)
 disable_trace_kprobe (kernel/trace/trace_kprobe.c:429)
 perf_trace_event_unreg.isra.2 (./include/linux/tracepoint.h:93 kernel/trace/trace_event_perf.c:168)
 perf_kprobe_destroy (kernel/trace/trace_event_perf.c:295)
 _free_event (kernel/events/core.c:4971)
 perf_event_release_kernel (kernel/events/core.c:5176)
 perf_release (kernel/events/core.c:5186)
 __fput (fs/file_table.c:321)
 task_work_run (./include/linux/sched.h:2056 (discriminator 1) kernel/task_work.c:179 (discriminator 1))
 exit_to_user_mode_prepare (./include/linux/resume_user_mode.h:49 kernel/entry/common.c:169 kernel/entry/common.c:201)
 syscall_exit_to_user_mode (./arch/x86/include/asm/jump_label.h:55 ./arch/x86/include/asm/nospec-branch.h:384 ./arch/x86/include/asm/entry-common.h:94 kernel/entry/common.c:133 kernel/entry/common.c:296)
 do_syscall_64 (arch/x86/entry/common.c:87)
 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
RIP: 0033:0x7fe7ff210654
Code: 15 79 89 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb be 0f 1f 00 8b 05 9a cd 20 00 48 63 ff 85 c0 75 11 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3a f3 c3 48 83 ec 18 48 89 7c 24 08 e8 34 fc
RSP: 002b:00007ffdbd1d3538 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007fe7ff210654
RDX: 0000000000000000 RSI: 0000000000002401 RDI: 0000000000000008
RBP: 0000000000000000 R08: 94ae31d6fda838a4 R0900007fe8001c9d30
R10: 00007ffdbd1d34b0 R11: 0000000000000246 R12: 00007ffdbd1d3600
R13: 0000000000000000 R14: fffffffffffffffc R15: 00007ffdbd1d3560
</TASK>

Link: https://lkml.kernel.org/r/20220813020509.90805-1-kuniyu@amazon.com
Fixes: 69d54b916d ("kprobes: makes kprobes/enabled works correctly for optimized kprobes.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reported-by: Ayushman Dutta <ayudutta@amazon.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Kuniyuki Iwashima <kuni1840@gmail.com>
Cc: Ayushman Dutta <ayudutta@amazon.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:23:58 +02:00
..
bpf bpf: fix overflow in prog accounting 2022-08-25 11:09:24 +02:00
configs
debug kdb: Make memory allocations more robust 2021-03-03 17:44:31 +01:00
events perf/core: Fix data race between perf_event_set_output() and perf_mmap_close() 2022-07-29 17:05:45 +02:00
gcov gcov: add support for GCC 10.1 2020-09-23 08:46:14 +02:00
irq random: remove unused irq_flags argument from add_interrupt_randomness() 2022-06-25 11:45:04 +02:00
livepatch
locking locking/lockdep: Avoid RCU-induced noinstr fail 2021-11-26 11:48:27 +01:00
power PM: suspend: fix return value of __setup handler 2022-04-20 09:06:31 +02:00
printk printk: fix return value of printk.devkmsg __setup handler 2022-04-20 09:06:33 +02:00
rcu rcuperf: Fix cleanup path for invalid perf_type strings 2019-05-31 06:48:30 -07:00
sched sched/debug: Remove mpol_get/put and task_lock/unlock from sched_show_numa 2022-04-20 09:06:32 +02:00
time timekeeping: Add raw clock fallback for random_get_entropy() 2022-06-25 11:45:13 +02:00
trace ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead 2022-09-05 10:23:57 +02:00
.gitignore
acct.c kernel/acct.c: fix the acct->needcheck check in check_free_space() 2018-01-10 09:29:51 +01:00
async.c kernel/async.c: revert "async: simplify lowest_in_progress()" 2018-02-17 13:21:18 +01:00
audit.c audit: fix a net reference leak in audit_list_rules_send() 2021-04-07 12:05:41 +02:00
audit.h audit: fix a net reference leak in audit_list_rules_send() 2021-04-07 12:05:41 +02:00
audit_fsnotify.c
audit_tree.c
audit_watch.c audit: CONFIG_CHANGE don't log internal bookkeeping as an event 2020-10-01 20:40:07 +02:00
auditfilter.c audit: fix a net reference leak in audit_list_rules_send() 2021-04-07 12:05:41 +02:00
auditsc.c audit: print empty EXECVE args 2019-11-28 18:28:55 +01:00
backtracetest.c
bounds.c kbuild: fix kernel/bounds.c 'W=1' warning 2018-11-13 11:16:57 -08:00
capability.c
cgroup.c cgroup-v1: Require capabilities to set release_agent 2022-02-11 08:41:17 +01:00
cgroup_freezer.c
cgroup_pids.c cgroup: pids: use atomic64_t for pids->limit 2019-12-21 10:42:02 +01:00
compat.c
configs.c
context_tracking.c
cpu.c random: clear fast pool, crng, and batches in cpuhp bring up 2022-06-25 11:45:10 +02:00
cpu_pm.c kernel/cpu_pm: Fix uninitted local in cpu_pm 2020-06-20 10:24:21 +02:00
cpuset.c
crash_dump.c
cred.c memcg: account security cred as well to kmemcg 2020-01-12 11:24:13 +01:00
delayacct.c
dma.c
exec_domain.c
exit.c security,selinux,smack: kill security_task_wait hook 2022-07-29 17:05:44 +02:00
extable.c
fork.c mm/hugetlb: initialize hugetlb_usage in mm_init 2021-09-22 11:43:08 +02:00
freezer.c
futex.c mm, futex: fix shared futex pgoff on shmem huge page 2021-07-11 12:46:40 +02:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2018-01-10 09:29:52 +01:00
hung_task.c kernel: hung_task.c: disable on suspend 2019-04-20 09:07:52 +02:00
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: ensure irq code sees a valid area 2018-08-03 07:55:12 +02:00
kexec.c
kexec_core.c objtool, x86: Add several functions and files to the objtool whitelist 2018-06-05 10:28:57 +02:00
kexec_file.c kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] 2022-07-02 16:17:16 +02:00
kexec_internal.h
kmod.c usermodehelper: reset umask to default before executing user process 2020-10-14 09:48:14 +02:00
kprobes.c kprobes: don't call disarm_kprobe() for disabled kprobes 2022-09-05 10:23:58 +02:00
ksysfs.c
kthread.c kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync() 2021-07-11 12:46:41 +02:00
latencytop.c
Makefile elfcore: fix building with clang 2021-02-10 09:09:25 +01:00
membarrier.c
memremap.c mm, devm_memremap_pages: kill mapping "System RAM" support 2019-01-13 10:03:51 +01:00
module-internal.h
module.c module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols 2021-03-03 17:44:44 +01:00
module_signing.c
notifier.c x86/mm: split vmalloc_sync_all() 2020-04-02 17:20:26 +02:00
nsproxy.c
padata.c padata: purge get_cpu and reorder_via_wq from padata_do_serial 2020-05-27 16:41:53 +02:00
panic.c panic: ensure preemption is disabled during panic() 2019-10-17 13:42:25 -07:00
params.c
pid.c pidns: disable pid allocation if pid_ns_prepare_proc() is failed in alloc_pid() 2018-04-13 19:47:53 +02:00
pid_namespace.c memcg: enable accounting for pids in nested pid namespaces 2021-09-22 11:43:08 +02:00
profile.c profiling: fix shift-out-of-bounds bugs 2021-09-26 13:36:18 +02:00
ptrace.c ptrace: Reimplement PTRACE_KILL by always sending SIGKILL 2022-06-14 16:52:28 +02:00
range.c
reboot.c reboot: fix overflow parsing reboot cpu number 2020-11-18 18:26:32 +01:00
relay.c kernel/relay.c: fix memleak on destroy relay channel 2020-08-26 10:29:03 +02:00
resource.c resource: fix integer overflow at reallocation 2018-04-24 09:34:09 +02:00
seccomp.c seccomp: Add missing return in non-void function 2021-03-03 17:44:43 +01:00
signal.c signal handling: don't use BUG_ON() for debugging 2022-07-21 20:40:32 +02:00
smp.c smp: Fix offline cpu check in flush_smp_call_function_queue() 2022-04-20 09:06:46 +02:00
smpboot.c
smpboot.h
softirq.c Mark HI and TASKLET softirq synchronous 2018-08-15 18:14:42 +02:00
stacktrace.c
stop_machine.c stop_machine: Use raw spinlocks 2018-08-03 07:55:24 +02:00
sys.c prctl: allow to setup brk for et_dyn executables 2021-09-26 13:36:18 +02:00
sys_ni.c
sysctl.c x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting 2022-03-11 10:03:31 +01:00
sysctl_binary.c
task_work.c
taskstats.c taskstats: fix data-race 2020-01-12 11:24:12 +01:00
test_kprobes.c
torture.c
tracepoint.c tracepoint: Do not fail unregistering a probe due to memory failure 2021-03-03 17:44:38 +01:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-02-23 11:56:40 +01:00
ucount.c
uid16.c kernel: make groups_sort calling a responsibility group_info allocators 2018-01-10 09:29:52 +01:00
up.c
user-return-notifier.c
user.c
user_namespace.c userns: move user access out of the mutex 2018-09-09 20:01:24 +02:00
utsname.c
utsname_sysctl.c sys: don't hold uts_sem while accessing userspace memory 2018-09-09 20:01:24 +02:00
watchdog.c
watchdog_hld.c
workqueue.c workqueue: make workqueue available early during boot 2022-06-25 11:45:09 +02:00
workqueue_internal.h