medium CVSS 5.5 EPSS <0.1%

CVE-2024-36977·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: Wait unconditionally after issuing EndXfer command Currently all controller IP/revisions except DWC3_usb3 >= 310a wait 1ms unconditionally for ENDXFER completion when IOC is not set. This is because DWC_usb3 controller revisions >= 3.10a supports GUCTL2[14: Rst_actbitlater] bit which allows polling CMDACT bit to know whether ENDXFER command is completed. Consider a case where an IN request was queued, and parallelly soft_disconnect was called (due to ffs_epfile_release). This eventually calls stop_active_transfer with IOC cleared, hence send_gadget_ep_cmd() skips waiting for CMDACT cleared during EndXfer. For DWC3 controllers with revisions >= 310a, we don't forcefully wait for 1ms either, and we proceed by unmapping the requests. If ENDXFER didn't complete by this time, it leads to SMMU faults since the controller would still be accessing those requests. Fix this by ensuring ENDXFER completion by adding 1ms delay in __dwc3_stop_active_transfer() unconditionally.

Severity
medium
Software
Kernel
Fixed in
6.9.2
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 10% 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.

Affected versions

From: 6.9

Until: 6.9.2

Fixed in: 6.9.2

How to fix this CVE

Update your Linux kernel to version 6.9.2 or later to resolve a USB DWC3 controller timing issue that can cause SMMU faults during device disconnection. This vulnerability affects systems with DWC3 USB 3.0 controllers running kernel versions 6.9 through 6.9.2. Apply the patch immediately to prevent potential system instability when USB devices are disconnected during active transfers.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your kernel version: uname -r
  2. Verify if you are running 6.9.0, 6.9.1, or 6.9.2: grep -i 'Linux version' /proc/version
  3. Check for USB DWC3 controller: lspci | grep -i dwc3 or dmesg | grep -i dwc3
  4. Verify fix by updating kernel and confirming new version: uname -r (should show 6.9.2 or later)
  5. Check system logs for SMMU faults or USB errors: dmesg | grep -i 'smmu\|usb.*error\|dwc3' | tail -20

FAQ

What is CVE-2024-36977?

This vulnerability affects the USB DWC3 controller driver in the Linux kernel. When a USB device is disconnected during an active data transfer, the ENDXFER command may not complete properly on certain controller revisions, causing the controller to continue accessing freed memory buffers and triggering SMMU faults.

Is CVE-2024-36977 being actively exploited?

No, this CVE is not being actively exploited in the wild and there are no public exploits available. It requires specific hardware (DWC3 USB 3.0 controllers) and a particular timing condition (soft disconnect during active transfer).

What versions of Kernel are affected by CVE-2024-36977?

Linux kernel versions 6.9, 6.9.1, and 6.9.2 are affected. The vulnerability is resolved in kernel 6.9.2 and later versions.

How do I check if my server is vulnerable to CVE-2024-36977?

Run 'uname -r' and check if your kernel version is 6.9.0, 6.9.1, or 6.9.2. If yes, verify the presence of DWC3 USB controller with 'lspci | grep -i dwc3' or 'dmesg | grep dwc3'. If both conditions are met, your system is vulnerable.

Does Defensia detect CVE-2024-36977?

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-2024-36977 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.
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References

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