CVE-2024-57887

What it actually does

Use-after-free in adv7533_attach_dsi() caused by premature of_node_put() on host_node in adv7533_parse_dt(); the freed pointer is later dereferenced during DSI attachment.

Why it matters to the business

Kernel memory corruption on systems using ADV7511/ADV7533 HDMI encoders can lead to crashes, denial of service, or local privilege escalation; older Ubuntu LTS releases carrying the vulnerable driver remain exposed until patched.

How an attack unfolds

An attacker with local access loads or triggers the adv7511 DRM driver, causing adv7533_parse_dt() to free the device-tree node; subsequent probe or attach paths in adv7533_attach_dsi() dereference the dangling pointer, enabling memory corruption that may be turned into code execution.

How to fix it

Update to fixed imagemagick packages: 8:6.7.7.10-6ubuntu3.11 on Ubuntu 14.04 LTS and 8:6.8.9.9-7ubuntu5.11 on Ubuntu 16.04 LTS; apply kernel patches that remove the premature of_node_put() and ensure balanced put() calls on probe error and remove paths.

How to confirm the fix worked

Verify package versions match the listed fixed releases; inspect kernel source for removal of of_node_put() from adv7533_parse_dt() and its addition to probe error and remove handlers; confirm no dangling node references remain in adv7533_attach_dsi().

Typical attack path

1. Obtain local shell on target Linux system
2. Trigger loading of the adv7511/adv7533 DRM driver (via hardware or module load)
3. Force device-tree parsing path that performs the erroneous of_node_put()
4. Trigger DSI attach in error or remove paths to dereference freed node
5. Leverage resulting UAF for memory corruption and privilege escalation

How to detect it

Review kernel logs for oops or panic traces referencing adv7533_attach_dsi or of_node_put; inspect device probe/remove sequences involving adv7511; look for unexpected module loads of drm_adv7511 or adv7533.

What your security team should do

• Prioritize patching Ubuntu 14.04/16.04 systems running the adv7511 driver within the next maintenance window
• Monitor for new kernel advisories addressing the same UAF pattern in DRM bridges
• Restrict unprivileged module loading and hardware access on multi-user systems until patches are deployed