CVE-2022-49014

CVE-2022-49014 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: net: tun: Fix use-after-free in tun_detach() syzbot reported use-after-free in tun_detach() [1]. This causes call trace like below: ================================================================== BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 Read of size 8 at addr ffff88807324e2a8 by task syz-executor.0/3673 CPU: 0 PID: 3673 Comm: syz-executor.0 Not tainted 6.1.0-rc5-syzkaller-00044-gcc675d22e422 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x461 mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 call_netdevice_notifiers_info+0x86/0x130 net/core/dev.c:1942 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] netdev_wait_allrefs_any net/core/dev.c:10237 [inline] netdev_run_todo+0xbc6/0x1100 net/core/dev.c:10351 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xe4/0x190 drivers/net/tun.c:3467 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb3d/0x2a30 kernel/exit.c:820 do_group_exit+0xd4/0x2a0 kernel/exit.c:950 get_signal+0x21b1/0x2440 kernel/signal.c:2858 arch_do_signal_or_restart+0x86/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The cause of the issue is that sock_put() from __tun_detach() drops last reference count for struct net, and then notifier_call_chain() from netdev_state_change() accesses that struct net. This patch fixes the issue by calling sock_put() from tun_detach() after all necessary accesses for the struct net has done.

Frequently asked questions

What is CVE-2022-49014?
In the Linux kernel, the following vulnerability has been resolved: net: tun: Fix use-after-free in tun_detach() syzbot reported use-after-free in tun_detach() [1]. This causes call trace like below: ================================================================== BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 Read of size 8 at addr ffff88807324e2a8 by task syz-executor.0/3673 CPU: 0 PID: 3673 Comm: syz-executor.0 Not tainted 6.1.0-rc5-syzkaller-00044-gcc675d22e422 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x461 mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 call_netdevice_notifiers_info+0x86/0x130 net/core/dev.c:1942 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] netdev_wait_allrefs_any net/core/dev.c:10237 [inline] netdev_run_todo+0xbc6/0x1100 net/core/dev.c:10351 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xe4/0x190 drivers/net/tun.c:3467 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb3d/0x2a30 kernel/exit.c:820 do_group_exit+0xd4/0x2a0 kernel/exit.c:950 get_signal+0x21b1/0x2440 kernel/signal.c:2858 arch_do_signal_or_restart+0x86/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The cause of the issue is that sock_put() from __tun_detach() drops last reference count for struct net, and then notifier_call_chain() from netdev_state_change() accesses that struct net. This patch fixes the issue by calling sock_put() from tun_detach() after all necessary accesses for the struct net has done.
How severe is CVE-2022-49014?
CVE-2022-49014 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2022-49014 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-49014?
CVE-2022-49014 primarily affects Linux Linux Kernel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2022-49014?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2022-49014 have an EU (EUVD) identifier?
Yes. CVE-2022-49014 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-53898.
When was CVE-2022-49014 published?
CVE-2022-49014 was published on 2024-10-21 and last updated on 2026-06-17.

References

Affected products (8)

More vulnerabilities in Linux Linux Kernel

All CVEs affecting Linux Linux Kernel →

Other CWE-416 (Use After Free) vulnerabilities

Browse all CWE-416 (Use After Free) vulnerabilities →