---
id: CVE-2022-49799
title: 'tracing: Fix wild-memory-access in register_synth_event()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tracing: Fix wild-memory-access in register_synth_event()

  In register_synth_event(), if set_synth_event_print_fmt() failed, then
  both trace_remove_event_call() and unr…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4b147936fa509650beaf638b331573c23ba4d609 <
    315b149f08229a233d47532eb5da1707b28f764c
  - >-
    Linux >= 4b147936fa509650beaf638b331573c23ba4d609 <
    6517b97134f724d12f673f9fb4f456d75c7a905f
  - >-
    Linux >= 4b147936fa509650beaf638b331573c23ba4d609 <
    a5bfa53e5036b3e7a80be902dd3719a930accabd
  - >-
    Linux >= 4b147936fa509650beaf638b331573c23ba4d609 <
    1b5f1c34d3f5a664a57a5a7557a50e4e3cc2505c
  - Linux 4.17
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:48:37.155107Z'
published: '2025-05-01'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T19:49:49.482Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-49799'
references:
  - url: 'https://git.kernel.org/stable/c/315b149f08229a233d47532eb5da1707b28f764c'
  - url: 'https://git.kernel.org/stable/c/6517b97134f724d12f673f9fb4f456d75c7a905f'
  - url: 'https://git.kernel.org/stable/c/a5bfa53e5036b3e7a80be902dd3719a930accabd'
  - url: 'https://git.kernel.org/stable/c/1b5f1c34d3f5a664a57a5a7557a50e4e3cc2505c'
tags:
  - cve.org
epss: 0.00205
epssPercentile: 0.10602
ingestedAt: '2026-11-05T22:38:31.597Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

tracing: Fix wild-memory-access in register_synth_event()

In register_synth_event(), if set_synth_event_print_fmt() failed, then
both trace_remove_event_call() and unregister_trace_event() will be
called, which means the trace_event_call will call
__unregister_trace_event() twice. As the result, the second unregister
will causes the wild-memory-access.

register_synth_event
    set_synth_event_print_fmt failed
    trace_remove_event_call
        event_remove
            if call->event.funcs then
            __unregister_trace_event (first call)
    unregister_trace_event
        __unregister_trace_event (second call)

Fix the bug by avoiding to call the second __unregister_trace_event() by
checking if the first one is called.

general protection fault, probably for non-canonical address
	0xfbd59c0000000024: 0000 [#1] SMP KASAN PTI
KASAN: maybe wild-memory-access in range
[0xdead000000000120-0xdead000000000127]
CPU: 0 PID: 3807 Comm: modprobe Not tainted
6.1.0-rc1-00186-g76f33a7eedb4 #299
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:unregister_trace_event+0x6e/0x280
Code: 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 0e 02 00 00 48
b8 00 00 00 00 00 fc ff df 4c 8b 63 08 4c 89 e2 48 c1 ea 03 <80> 3c 02
00 0f 85 e2 01 00 00 49 89 2c 24 48 85 ed 74 28 e8 7a 9b
RSP: 0018:ffff88810413f370 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffff888105d050b0 RCX: 0000000000000000
RDX: 1bd5a00000000024 RSI: ffff888119e276e0 RDI: ffffffff835a8b20
RBP: dead000000000100 R08: 0000000000000000 R09: fffffbfff0913481
R10: ffffffff8489a407 R11: fffffbfff0913480 R12: dead000000000122
R13: ffff888105d050b8 R14: 0000000000000000 R15: ffff888105d05028
FS:  00007f7823e8d540(0000) GS:ffff888119e00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7823e7ebec CR3: 000000010a058002 CR4: 0000000000330ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __create_synth_event+0x1e37/0x1eb0
 create_or_delete_synth_event+0x110/0x250
 synth_event_run_command+0x2f/0x110
 test_gen_synth_cmd+0x170/0x2eb [synth_event_gen_test]
 synth_event_gen_test_init+0x76/0x9bc [synth_event_gen_test]
 do_one_initcall+0xdb/0x480
 do_init_module+0x1cf/0x680
 load_module+0x6a50/0x70a0
 __do_sys_finit_module+0x12f/0x1c0
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

## Affected

- `Linux >= 4b147936fa509650beaf638b331573c23ba4d609 < 315b149f08229a233d47532eb5da1707b28f764c`
- `Linux >= 4b147936fa509650beaf638b331573c23ba4d609 < 6517b97134f724d12f673f9fb4f456d75c7a905f`
- `Linux >= 4b147936fa509650beaf638b331573c23ba4d609 < a5bfa53e5036b3e7a80be902dd3719a930accabd`
- `Linux >= 4b147936fa509650beaf638b331573c23ba4d609 < 1b5f1c34d3f5a664a57a5a7557a50e4e3cc2505c`
- `Linux 4.17`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.