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Yang Jihong ddffe882d7 ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead 
commit c3b0f72e805f0801f05fa2aa52011c4bfc694c44 upstream.

ftrace_startup does not remove ops from ftrace_ops_list when
ftrace_startup_enable fails:

register_ftrace_function
  ftrace_startup
    __register_ftrace_function
      ...
      add_ftrace_ops(&ftrace_ops_list, ops)
      ...
    ...
    ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1
    ...
  return 0 // ops is in the ftrace_ops_list.

When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything:
unregister_ftrace_function
  ftrace_shutdown
    if (unlikely(ftrace_disabled))
            return -ENODEV;  // return here, __unregister_ftrace_function is not executed,
                             // as a result, ops is still in the ftrace_ops_list
    __unregister_ftrace_function
    ...

If ops is dynamically allocated, it will be free later, in this case,
is_ftrace_trampoline accesses NULL pointer:

is_ftrace_trampoline
  ftrace_ops_trampoline
    do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL!

Syzkaller reports as follows:
[ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b
[ 1203.508039] #PF: supervisor read access in kernel mode
[ 1203.508798] #PF: error_code(0x0000) - not-present page
[ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0
[ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI
[ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G    B   W         5.10.0 #8
[ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0
[ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00
[ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246
[ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866
[ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b
[ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07
[ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399
[ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008
[ 1203.525634] FS:  00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
[ 1203.526801] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0
[ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Therefore, when ftrace_startup_enable fails, we need to rollback registration
process and remove ops from ftrace_ops_list.

Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:26:34 +02:00
..
bpf
bpf: Verifer, adjust_scalar_min_max_vals to always call update_reg_bounds()
2022-08-25 11:14:55 +02:00
cgroup
cgroup: Use separate src/dst nodes when preloading css_sets for migration
2022-07-21 21:09:26 +02:00
configs
kconfig: tinyconfig: remove stale stack protector fixups
2018-06-15 07:15:28 +09:00
debug
kdb: Make memory allocations more robust
2021-03-04 09:39:31 +01:00
dma
swiotlb: skip swiotlb_bounce when orig_addr is zero
2022-07-02 16:27:40 +02:00
events
perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()
2022-07-29 17:10:31 +02:00
gcov
gcov: add support for GCC 10.1
2020-09-17 13:45:31 +02:00
irq
random: remove unused irq_flags argument from add_interrupt_randomness()
2022-06-25 11:49:01 +02:00
livepatch
livepatch: Nullify obj->mod in klp_module_coming()'s error path
2019-10-07 18:57:10 +02:00
locking
locking/lockdep: Avoid RCU-induced noinstr fail
2021-11-26 11:36:04 +01:00
power
PM: hibernate: defer device probing when resuming from hibernation
2022-08-25 11:15:00 +02:00
printk
printk: fix return value of printk.devkmsg __setup handler
2022-04-15 14:14:45 +02:00
rcu
rcu: Fix missed wakeup of exp_wq waiters
2021-09-26 13:39:46 +02:00
sched
sched/deadline: Fix priority inheritance with multiple scheduling classes
2022-09-05 10:26:28 +02:00
time
timekeeping: Add raw clock fallback for random_get_entropy()
2022-06-25 11:49:10 +02:00
trace
ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
2022-09-05 10:26:34 +02:00
.gitignore
…
acct.c
acct_on(): don't mess with freeze protection
2019-05-31 06:46:05 -07:00
async.c
Revert "module, async: async_synchronize_full() on module init iff async is used"
2022-02-23 11:58:38 +01:00
audit_fsnotify.c
audit: fix potential double free on error path from fsnotify_add_inode_mark
2022-09-05 10:26:28 +02:00
audit_tree.c
audit: Embed key into chunk
2019-12-13 08:51:11 +01:00
audit_watch.c
audit: CONFIG_CHANGE don't log internal bookkeeping as an event
2020-10-01 13:14:33 +02:00
audit.c
audit: improve audit queue handling when "audit=1" on cmdline
2022-02-08 18:23:13 +01:00
audit.h
audit: fix a net reference leak in audit_list_rules_send()
2020-06-22 09:05:13 +02:00
auditfilter.c
audit: fix a net reference leak in audit_list_rules_send()
2020-06-22 09:05:13 +02:00
auditsc.c
audit: print empty EXECVE args
2019-12-01 09:17:17 +01:00
backtracetest.c
…
bounds.c
kbuild: fix kernel/bounds.c 'W=1' warning
2018-11-13 11:08:47 -08:00
capability.c
LSM: generalize flag passing to security_capable
2020-01-23 08:21:29 +01:00
compat.c
make 'user_access_begin()' do 'access_ok()'
2020-06-22 09:04:58 +02:00
configs.c
…
context_tracking.c
…
cpu_pm.c
kernel/cpu_pm: Fix uninitted local in cpu_pm
2020-06-22 09:05:28 +02:00
cpu.c
random: clear fast pool, crng, and batches in cpuhp bring up
2022-06-25 11:49:07 +02:00
crash_core.c
kernel/crash_core.c: print timestamp using time64_t
2018-08-22 10:52:47 -07:00
crash_dump.c
…
cred.c
memcg: account security cred as well to kmemcg
2020-01-09 10:19:00 +01:00
delayacct.c
…
dma.c
…
exec_domain.c
…
exit.c
futex: Mark the begin of futex exit explicitly
2021-01-30 13:32:11 +01:00
extable.c
…
fail_function.c
fail_function: Remove a redundant mutex unlock
2020-11-24 13:27:23 +01:00
fork.c
mm/hugetlb: initialize hugetlb_usage in mm_init
2021-09-22 11:48:09 +02:00
freezer.c
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
futex.c
mm, futex: fix shared futex pgoff on shmem huge page
2021-07-11 12:49:30 +02:00
groups.c
…
hung_task.c
kernel: hung_task.c: disable on suspend
2019-04-20 09:16:02 +02:00
iomem.c
…
irq_work.c
irq_work: Do not raise an IPI when queueing work on the local CPU
2019-05-31 06:46:19 -07:00
jump_label.c
locking/static_key: Fix false positive warnings on concurrent dec/inc
2021-03-04 09:39:30 +01:00
kallsyms.c
kallsyms: Refactor kallsyms_show_value() to take cred
2020-07-16 08:17:26 +02:00
kcmp.c
…
Kconfig.freezer
…
Kconfig.hz
…
Kconfig.locks
…
Kconfig.preempt
kconfig: include kernel/Kconfig.preempt from init/Kconfig
2018-08-02 08:06:54 +09:00
kcov.c
kernel/kcov.c: mark write_comp_data() as notrace
2019-02-12 19:47:20 +01:00
kexec_core.c
kernel: kexec: remove the lock operation of system_transition_mutex
2021-02-03 23:23:23 +01:00
kexec_file.c
kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]
2022-07-02 16:27:39 +02:00
kexec_internal.h
…
kexec.c
kexec: add call to LSM hook in original kexec_load syscall
2018-07-16 12:31:57 -07:00
kmod.c
kmod: make request_module() return an error when autoloading is disabled
2020-04-17 10:48:52 +02:00
kprobes.c
kprobes: Forbid probing on trampoline and BPF code areas
2022-08-25 11:15:25 +02:00
ksysfs.c
…
kthread.c
kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()
2021-07-11 12:49:31 +02:00
latencytop.c
…
Makefile
elfcore: fix building with clang
2021-02-10 09:21:06 +01:00
memremap.c
mm/memory_hotplug: shrink zones when offlining memory
2020-01-29 16:43:27 +01:00
module_signing.c
modsign: log module name in the event of an error
2018-07-02 11:36:17 +02:00
module-internal.h
modsign: log module name in the event of an error
2018-07-02 11:36:17 +02:00
module.c
Revert "module, async: async_synchronize_full() on module init iff async is used"
2022-02-23 11:58:38 +01:00
notifier.c
x86/mm: split vmalloc_sync_all()
2020-03-25 08:06:13 +01:00
nsproxy.c
…
padata.c
padata: add separate cpuhp node for CPUHP_PADATA_DEAD
2021-08-08 08:54:30 +02:00
panic.c
kernel/panic.c: do not append newline to the stack protector panic string
2019-12-01 09:17:10 +01:00
params.c
…
pid_namespace.c
memcg: enable accounting for pids in nested pid namespaces
2021-09-22 11:48:09 +02:00
pid.c
Fix failure path in alloc_pid()
2019-01-13 09:51:06 +01:00
profile.c
profiling: fix shift too large makes kernel panic
2022-08-25 11:15:20 +02:00
ptrace.c
ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
2022-06-14 16:59:14 +02:00
range.c
…
reboot.c
reboot: fix overflow parsing reboot cpu number
2020-11-18 19:18:52 +01:00
relay.c
kernel/relay.c: fix memleak on destroy relay channel
2020-08-26 10:30:59 +02:00
resource.c
resource: fix locking in find_next_iomem_res()
2019-09-16 08:22:20 +02:00
rseq.c
rseq: uapi: Declare rseq_cs field as union, update includes
2018-07-10 22:18:52 +02:00
seccomp.c
seccomp: Invalidate seccomp mode to catch death failures
2022-02-16 12:51:47 +01:00
signal.c
signal handling: don't use BUG_ON() for debugging
2022-07-21 21:09:32 +02:00
smp.c
smp: Fix offline cpu check in flush_smp_call_function_queue()
2022-04-20 09:12:50 +02:00
smpboot.c
kthread: Extract KTHREAD_IS_PER_CPU
2021-02-07 14:48:38 +01:00
smpboot.h
…
softirq.c
nohz: Fix missing tick reprogram when interrupting an inline softirq
2018-08-03 15:52:10 +02:00
stacktrace.c
…
stop_machine.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
sys_ni.c
kernel/sys_ni: add compat entry for fadvise64_64
2022-09-05 10:26:28 +02:00
sys.c
prctl: allow to setup brk for et_dyn executables
2021-09-26 13:39:47 +02:00
sysctl_binary.c
…
sysctl.c
x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting
2022-03-11 10:15:11 +01:00
task_work.c
…
taskstats.c
taskstats: fix data-race
2020-01-09 10:18:59 +01:00
test_kprobes.c
kprobes: Remove jprobe API implementation
2018-06-21 12:33:05 +02:00
torture.c
torture: Keep old-school dmesg format
2018-06-25 11:30:10 -07:00
tracepoint.c
tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing
2021-07-20 16:15:42 +02:00
tsacct.c
taskstats: Cleanup the use of task->exit_code
2022-02-23 11:58:39 +01:00
ucount.c
…
uid16.c
…
uid16.h
…
umh.c
usermodehelper: reset umask to default before executing user process
2020-10-14 10:31:21 +02:00
up.c
smp: Fix smp_call_function_single_async prototype
2021-05-22 10:59:39 +02:00
user_namespace.c
userns: also map extents in the reverse map to kernel IDs
2018-11-13 11:09:00 -08:00
user-return-notifier.c
…
user.c
userns: use irqsave variant of refcount_dec_and_lock()
2018-08-22 10:52:47 -07:00
utsname_sysctl.c
sys: don't hold uts_sem while accessing userspace memory
2018-08-11 02:05:53 -05:00
utsname.c
…
watchdog_hld.c
watchdog: Mark watchdog touch functions as notrace
2018-08-30 12:56:40 +02:00
watchdog.c
watchdog: export lockup_detector_reconfigure
2022-08-25 11:15:46 +02:00
workqueue_internal.h
…
workqueue.c
workqueue: make sysfs of unbound kworker cpumask more clever
2021-11-26 11:36:06 +01:00