drm: fix race between partial drm_dev_register() failure and ioctl

Summary

In the Linux kernel, the following vulnerability has been resolved: drm: fix race between partial drm_dev_register() failure and ioctl If drm_dev_register() fails after registering a minor (e.g. render minor registered, primary minor fails), userspace could have opened the first minor and entered a drm_dev_enter() critical section. Since the unplugged flag was never set, the ioctl proceeds while the error path tears down device resources. Fix this by introducing drm_dev_synchronize_unplug(), which sets the unplugged flag and waits for the SRCU barrier, ensuring all in-flight drm_dev_enter() critical sections complete before cleanup proceeds; call it on the error path of drm_dev_register().

Timeline

1. Sep 16, 2026, 10:30 AM UTCCVE published
2. Oct 19, 2026, 8:53 AM UTCRecord last updated

Affected versions

• Linux Linux

  From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in 26d9162213952927cd59c0d94b7e0e992b347bec; From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in 24d28d15c0f7f7d4a1c229f8730314f0f8758810; From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in 6729990df9e70623bf53f855b521ae71ca9cb278; From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in a0a7e2e177f2f18b9e7318a4c64ac44efd9ef22c; From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in 19dbfe4d586aecfed121cb3fa62281761d9d341f; From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in 79d09cfe90304ff4f195e47d569800f5e0f8b854; From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in 2d1215a72159d00001e08dee162e27718934bee9; From bee330f3d67273a68dcb99f59480d59553c008b2 · fixed in eb197f7d60f00d0f5b1b3505dfc86a7e36045a3e

• Linux Linux

  4.18

• KernelLinux

  From 4.18.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5

References 8