CVE-2022-50317: drm/bridge: megachips: Fix a null pointer dereference bug

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-15 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: drm/bridge: megachips: Fix a null pointer dereference bug When removing the module we will get the following warning: [ 31.911505] i2c-core: driver [stdp2690-ge-b850v3-fw] unregistered [ 31.912484] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI [ 31.913338] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] [ 31.915280] RIP: 0010:drm_bridge_remove+0x97/0x130 [ 31.921825] Call Trace: [ 31.922533] stdp4028_ge_b850v3_fw_remove+0x34/0x60 [megachips_stdpxxxx_ge_b850v3_fw] [ 31.923139] i2c_device_remove+0x181/0x1f0 The two bridges (stdp2690, stdp4028) do not probe at the same time, so the driver does not call ge_b850v3_resgiter() when probing, causing the driver to try to remove the object that has not been initialized. Fix this by checking whether both the bridges are probed.

Affected products

Linux kernel: from 4.14.263 before 4.14.296; from 4.19.226 before 4.19.262; from 5.4.174 before 5.4.220; from 5.10.94 before 5.10.150; from 5.15.17 before 5.15.75; from 5.16.3 before 5.19.17 — fixed in 4.14.296, 4.19.262, 5.10.150, 5.15.75, 5.19.17, 5.4.220

How to fix

Upgrade to a fixed version: Linux kernel 4.14.296, 4.19.262, 5.10.150, 5.15.75. Check the vendor advisory for mitigations.

References

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