CVE-2024-42101

What it actually does

Null pointer dereference in nouveau_connector_get_modes when drm_mode_duplicate returns NULL without a subsequent check before use of the mode pointer.

Why it matters to the business

Kernel crashes or denial of service on Linux systems using the Nouveau driver for NVIDIA GPUs, potentially disrupting graphics workloads and requiring reboots with risk of data corruption during active sessions.

How an attack unfolds

An attacker triggers nouveau_connector_get_modes under memory pressure or malformed display mode conditions so that drm_mode_duplicate fails, then relies on the missing NULL check to dereference an invalid pointer; listed threat actors in Linux kernel campaigns could attempt similar resource-manipulation paths but public exploitation remains unlikely given low EPSS.

How to fix it

Apply the upstream fix by updating the Linux kernel to include commit 9baf60323efa992b7c915094529f0a1882c34e7e (or equivalent stable backports) which adds the required NULL check after drm_mode_duplicate.

How to confirm the fix worked

Confirm the patched source contains an explicit NULL check on the return value of drm_mode_duplicate before dereferencing the mode variable inside nouveau_connector_get_modes; test by attempting mode operations under low-memory conditions.

Typical attack path

1. Gain local access or influence display configuration on a Nouveau-enabled system
2. Force drm_mode_duplicate allocation failure via memory exhaustion or crafted EDID/mode data
3. Execute the unchecked assignment and subsequent use of the NULL mode pointer
4. Trigger kernel oops or panic from the resulting NULL dereference

How to detect it

Search kernel ring buffers and system logs for oops or panic messages referencing nouveau_connector_get_modes or drm_mode_duplicate failures; correlate with processes performing display mode enumeration.

• nouveau_connector_get_modes
• BUG: unable to handle kernel NULL pointer dereference
• drm_mode_duplicate

What your security team should do

• Prioritize kernel updates containing 9baf60323efa992b7c915094529f0a1882c34e7e on all systems using the Nouveau driver
• Monitor kernel logs for nouveau-related NULL pointer oops until patches are deployed
• Limit untrusted local access or graphics configuration changes on unpatched hosts
• Review downstream kernel packages for backported equivalents of the fix