high CVSS 7.8 EPSS <0.1%

CVE-2022-49686·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: fix list double add in uvcg_video_pump A panic can occur if the endpoint becomes disabled and the uvcg_video_pump adds the request back to the req_free list after it has already been queued to the endpoint. The endpoint complete will add the request back to the req_free list. Invalidate the local request handle once it's been queued. <6>[ 246.796704][T13726] configfs-gadget gadget: uvc: uvc_function_set_alt(1, 0) <3>[ 246.797078][ T26] list_add double add: new=ffffff878bee5c40, prev=ffffff878bee5c40, next=ffffff878b0f0a90. <6>[ 246.797213][ T26] ------------[ cut here ]------------ <2>[ 246.797224][ T26] kernel BUG at lib/list_debug.c:31! <6>[ 246.807073][ T26] Call trace: <6>[ 246.807180][ T26] uvcg_video_pump+0x364/0x38c <6>[ 246.807366][ T26] process_one_work+0x2a4/0x544 <6>[ 246.807394][ T26] worker_thread+0x350/0x784 <6>[ 246.807442][ T26] kthread+0x2ac/0x320

Severity
high
Software
Kernel
Fixed in
5.18.8
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 12% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2022-49686 scores 7.8 on CVSS, so a successful attack would be serious — but at <0.1%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

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 critical USB gadget UVC driver vulnerability that can trigger kernel panics. This issue affects USB device mode functionality and requires immediate patching to prevent system instability during USB endpoint operations.

sudo dnf update kernel

Defensia detects this vulnerability

How to check if you are affected

  1. Check current kernel version: uname -r (compare against 5.16.0 to 5.18.8 range)
  2. Verify USB gadget UVC module is loaded: lsmod | grep uvc (if output shows uvc_gadget, component is active)
  3. Search kernel logs for panic indicators: sudo dmesg | grep -E 'list_add double add|uvcg_video_pump|BUG at lib/list_debug'
  4. Confirm patch applied: grep -i 'uvcg_video_pump' /boot/config-$(uname -r) and verify kernel version is >= 5.18.8

FAQ

What is CVE-2022-49686?

This vulnerability exists in the Linux kernel's USB gadget UVC (USB Video Class) driver, where improper request queue management causes the kernel to attempt adding the same request to a free list twice, resulting in a kernel panic and system crash.

Is CVE-2022-49686 being actively exploited?

No, this vulnerability is not listed as actively exploited in the CISA Known Exploited Vulnerabilities catalog, and no public exploits are currently available.

What versions of Kernel are affected by CVE-2022-49686?

Linux kernel versions 5.16.0 through 5.18.7 are vulnerable; version 5.18.8 and later contain the fix.

How do I check if my server is vulnerable to CVE-2022-49686?

Run 'uname -r' to check your kernel version; if it shows 5.16.x through 5.18.7, you are vulnerable. Additionally, run 'lsmod | grep uvc' to verify if USB gadget UVC functionality is loaded on your system.

Does Defensia detect CVE-2022-49686?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2022-49686 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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CVE-2026-53384CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails dw8250_probe() registers the 8250 port via serial8250_register_8250_port() and then, if the device has a clock, registers a clock notifier. If clk_notifier_register() fails, probe returns the error but leaves the 8250 port registered. The matching serial8250_unregister_port() lives in dw8250_remove(), which is not called when probe fails, so the port slot stays occupied until the device is rebound or the system is rebooted. The devm-allocated driver data is freed while the port still references it (via the saved private_data and serial_in/serial_out callbacks), so any access to that port slot before a rebind is a use-after-free hazard. Unregister the port on the clk_notifier_register() error path.
CVE-2026-52931CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: batman-adv: tp_meter: avoid use of uninit sender vars batadv_tp_recv_ack() and batadv_tp_stop() are only valid for tp_vars in the BATADV_TP_SENDER role. When called with a BATADV_TP_RECEIVER role, it proceeds to read sender-only members that were never initialized, leading to undefined behavior. This can be triggered when a node that is currently acting as a receiver in an ongoing tp_meter session receives a malicious ACK packet. Guard against this by checking tp_vars->role immediately after the lookup and bailing out if it is not BATADV_TP_SENDER, before any of those members are accessed.
CVE-2026-52982CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: net: usb: rtl8150: fix use-after-free in rtl8150_start_xmit() syzbot reported a KASAN slab-use-after-free read in rtl8150_start_xmit() when accessing skb->len for tx statistics after usb_submit_urb() has been called: BUG: KASAN: slab-use-after-free in rtl8150_start_xmit+0x71f/0x760 drivers/net/usb/rtl8150.c:712 Read of size 4 at addr ffff88810eb7a930 by task kworker/0:4/5226 The URB completion handler write_bulk_callback() frees the skb via dev_kfree_skb_irq(dev->tx_skb). The URB may complete on another CPU in softirq context before usb_submit_urb() returns in the submitter, so by the time the submitter reads skb->len the skb has already been queued to the per-CPU completion_queue and freed by net_tx_action(): CPU A (xmit) CPU B (USB completion softirq) ------------ ------------------------------ dev->tx_skb = skb; usb_submit_urb() --+ |-------> write_bulk_callback() | dev_kfree_skb_irq(dev->tx_skb) | net_tx_action() | napi_skb_cache_put() <-- free netdev->stats.tx_bytes | += skb->len; <-- UAF read Fix it by caching skb->len before submitting the URB and using the cached value when updating the tx_bytes counter. The pre-existing tx_bytes semantics are preserved: the counter tracks the original frame length (skb->len), not the ETH_ZLEN/USB-alignment padded "count" value that is handed to the device. Changing that would be a user-visible accounting change and is out of scope for this UAF fix.

References

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