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.
Product status
ec558bbfea671ac020a6dc6be8bf8f0ee556cce0 (git) before 9f2b87bcdfed55145acbf932dc12f2c057145cad
ec558bbfea671ac020a6dc6be8bf8f0ee556cce0 (git) before b2801647c203a38e013802e9e9616b5bfac64968
ec558bbfea671ac020a6dc6be8bf8f0ee556cce0 (git) before 51667fe2d9294d66e0228b9f51d1f01b6680a641
ec558bbfea671ac020a6dc6be8bf8f0ee556cce0 (git) before 6b526dca0966f2370835765019a54319b78fca8d
6.7
Any version before 6.7
6.12.86 (semver)
6.18.27 (semver)
7.0.4 (semver)
7.1-rc1 (original_commit_for_fix)
References
git.kernel.org/...c/9f2b87bcdfed55145acbf932dc12f2c057145cad
git.kernel.org/...c/b2801647c203a38e013802e9e9616b5bfac64968
git.kernel.org/...c/51667fe2d9294d66e0228b9f51d1f01b6680a641
git.kernel.org/...c/6b526dca0966f2370835765019a54319b78fca8d