CVE-2026-46041 greybus: gb-beagleplay: fix sleep in atomic context in hdlc_tx_frames()

What is CVE-2026-46041?

CVE-2026-46041 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

greybus: gb-beagleplay: fix sleep in atomic context in hdlc_tx_frames()

hdlc_append() calls usleep_range() to wait for circular buffer space, but it is called with tx_producer_lock (a spinlock) held via hdlc_tx_frames() -> hdlc_append_tx_frame()/hdlc_append_tx_u8()/etc. Sleeping while holding a spinlock is illegal and can trigger "BUG: scheduling while atomic".

Fix this by moving the buffer-space wait out of hdlc_append() and into hdlc_tx_frames(), before the spinlock is acquired. The new flow:

1. Pre-calculate the worst-case encoded frame length. 2. Wait (with sleep) outside the lock until enough space is available, kicking the TX consumer work to drain the buffer. 3. Acquire the spinlock, re-verify space, and write the entire frame atomically.

This ensures that sleeping only happens without any lock held, and that frames are either fully enqueued or not written at all.

This bug is found by CodeQL static analysis tool (interprocedural sleep-in-atomic query) and my code review.

Which versions are affected by CVE-2026-46041?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-46041?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-46041 being exploited?

There is no known exploitation of CVE-2026-46041 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-46041, DEBIAN-CVE-2026-46041, GHSA-f857-h46c-q655, ROOT-OS-UBUNTU-2404-CVE-2026-46041, UBUNTU-CVE-2026-46041.