CVE-2022-49696·Kernel vulnerability
In the Linux kernel, the following vulnerability has been resolved: tipc: fix use-after-free Read in tipc_named_reinit syzbot found the following issue on: ================================================================== BUG: KASAN: use-after-free in tipc_named_reinit+0x94f/0x9b0 net/tipc/name_distr.c:413 Read of size 8 at addr ffff88805299a000 by task kworker/1:9/23764 CPU: 1 PID: 23764 Comm: kworker/1:9 Not tainted 5.18.0-rc4-syzkaller-00878-g17d49e6e8012 #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events tipc_net_finalize_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 tipc_named_reinit+0x94f/0x9b0 net/tipc/name_distr.c:413 tipc_net_finalize+0x234/0x3d0 net/tipc/net.c:138 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 </TASK> [...] ================================================================== In the commit d966ddcc3821 ("tipc: fix a deadlock when flushing scheduled work"), the cancel_work_sync() function just to make sure ONLY the work tipc_net_finalize_work() is executing/pending on any CPU completed before tipc namespace is destroyed through tipc_exit_net(). But this function is not guaranteed the work is the last queued. So, the destroyed instance may be accessed in the work which will try to enqueue later. In order to completely fix, we re-order the calling of cancel_work_sync() to make sure the work tipc_net_finalize_work() was last queued and it must be completed by calling cancel_work_sync().
- Severity
- high
- Software
- Kernel
- Fixed in
- 5.18.8
- Published
- 2025-02-26
Affected versions
From: 5.16
Until: 5.18.8
Fixed in: 5.18.8
How to fix this CVE
Update your Linux kernel to version 5.18.8 or later to resolve a use-after-free vulnerability in the TIPC networking subsystem. This vulnerability allows a local attacker with unprivileged access to trigger a kernel panic or potentially execute arbitrary code by exploiting improper work queue synchronization during network namespace cleanup. Ensure all systems running kernel versions 5.16 through 5.18.7 are patched immediately.
sudo dnf update kernel kernel-develDefensia detects this vulnerability
How to check if you are affected
- Check your kernel version: uname -r | awk -F. '{print $1"."$2"."$3}' and verify if it falls between 5.16.0 and 5.18.7
- Verify TIPC module is loaded: lsmod | grep tipc — if present, the system is using the vulnerable code path
- Search kernel logs for TIPC-related errors: grep -i tipc /var/log/kern.log or journalctl -k | grep tipc
- Confirm patch status by checking if kernel version is 5.18.8 or later: uname -r should show a version >= 5.18.8
FAQ
What is CVE-2022-49696?
A use-after-free memory vulnerability in Linux kernel's TIPC (Transparent Inter-Process Communication) subsystem that occurs when the network namespace cleanup work queue is not properly synchronized, allowing freed memory to be accessed.
Is CVE-2022-49696 being actively exploited?
No, this vulnerability is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and has no publicly available exploits, though local attackers with standard user privileges could potentially trigger it.
What versions of Kernel are affected by CVE-2022-49696?
Linux kernel versions 5.16.0 through 5.18.7 are vulnerable; the fix was released in kernel 5.18.8 and backported to stable branches.
How do I check if my server is vulnerable to CVE-2022-49696?
Run `uname -r` to get your kernel version and verify it is not 5.18.8 or later; then check if TIPC is enabled with `grep -i tipc /boot/config-$(uname -r)` or `lsmod | grep tipc`.
Does Defensia detect CVE-2022-49696?
Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2022-49696 will appear in your dashboard with remediation steps.
Related Kernel CVEs
References
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