drm/meson: remove drm bridges at aggregate driver unbind time (CVE-2022-50256) | HOL Guard CVE

High · CVSS 7.8CVE-2022-50256

drm/meson: remove drm bridges at aggregate driver unbind time

Answer in brief

CVE-2022-50256 records a High severity (CVSS 7.8) vulnerability in drm/meson: remove drm bridges at aggregate driver unbind time. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 15, 2025Updated Aug 15, 2026Source checked Oct 1, 2026First seen by HOL Aug 15, 2026Material review Aug 15, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=e67f6037ae1be34b2b686bab72caa41d57714534 <de2b6ebe0cb7746b5b6b35d79e150d934392b958 \|\| >=e67f6037ae1be34b2b686bab72caa41d57714534 <fc1fd114dde3d2623ac37676df3d74ffeedb0da8 \|\| >=e67f6037ae1be34b2b686bab72caa41d57714534 <09847723c12fc2753749cec3939a02ee92dac468 \|\| 1c5439a716122cd86530d261cd1bf7ba43b3cdd8 \|\| 7e88f6d40f5875212f9d9ee8ba19147159908d4a \|\| >=5.15.33 <5.16 \|\| >=5.16.19 <5.17	de2b6ebe0cb7746b5b6b35d79e150d934392b958, fc1fd114dde3d2623ac37676df3d74ffeedb0da8, 09847723c12fc2753749cec3939a02ee92dac468, 5.16, 5.17
Linux/Linuxgeneric	5.17	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to de2b6ebe0cb7746b5b6b35d79e150d934392b958 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 15, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 15, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: drm/meson: remove drm bridges at aggregate driver unbind time drm bridges added by meson_encoder_hdmi_init and meson_encoder_cvbs_init were not manually removed at module unload time, which caused dangling references to freed memory to remain linked in the global bridge_list. When loading the driver modules back in, the same functions would again call drm_bridge_add, and when traversing the global bridge_list, would end up peeking into freed memory. Once again KASAN revealed the problem: [ +0.000095] ============================================================= [ +0.000008] BUG: KASAN: use-after-free in __list_add_valid+0x9c/0x120 [ +0.000018] Read of size 8 at addr ffff00003da291f0 by task modprobe/2483 [ +0.000018] CPU: 3 PID: 2483 Comm: modprobe Tainted: G C O 5.19.0-rc6-lrmbkasan+ #1 [ +0.000011] Hardware name: Hardkernel ODROID-N2Plus (DT) [ +0.000008] Call trace: [ +0.000006] dump_backtrace+0x1ec/0x280 [ +0.000012] show_stack+0x24/0x80 [ +0.000008] dump_stack_lvl+0x98/0xd4 [ +0.000011] print_address_description.constprop.0+0x80/0x520 [ +0.000011] print_report+0x128/0x260 [ +0.000008] kasan_report+0xb8/0xfc [ +0.000008] __asan_report_load8_noabort+0x3c/0x50 [ +0.000009] __list_add_valid+0x9c/0x120 [ +0.000009] drm_bridge_add+0x6c/0x104 [drm] [ +0.000165] dw_hdmi_probe+0x1900/0x2360 [dw_hdmi] [ +0.000022] meson_dw_hdmi_bind+0x520/0x814 [meson_dw_hdmi] [ +0.000014] component_bind+0x174/0x520 [ +0.000012] component_bind_all+0x1a8/0x38c [ +0.000010] meson_drv_bind_master+0x5e8/0xb74 [meson_drm] [ +0.000032] meson_drv_bind+0x20/0x2c [meson_drm] [ +0.000027] try_to_bring_up_aggregate_device+0x19c/0x390 [ +0.000010] component_master_add_with_match+0x1c8/0x284 [ +0.000009] meson_drv_probe+0x274/0x280 [meson_drm] [ +0.000026] platform_probe+0xd0/0x220 [ +0.000009] really_probe+0x3ac/0xa80 [ +0.000009] __driver_probe_device+0x1f8/0x400 [ +0.000009] driver_probe_device+0x68/0x1b0 [ +0.000009] __driver_attach+0x20c/0x480 [ +0.000008] bus_for_each_dev+0x114/0x1b0 [ +0.000009] driver_attach+0x48/0x64 [ +0.000008] bus_add_driver+0x390/0x564 [ +0.000009] driver_register+0x1a8/0x3e4 [ +0.000009] __platform_driver_register+0x6c/0x94 [ +0.000008] meson_drm_platform_driver_init+0x3c/0x1000 [meson_drm] [ +0.000027] do_one_initcall+0xc4/0x2b0 [ +0.000011] do_init_module+0x154/0x570 [ +0.000011] load_module+0x1a78/0x1ea4 [ +0.000008] __do_sys_init_module+0x184/0x1cc [ +0.000009] __arm64_sys_init_module+0x78/0xb0 [ +0.000009] invoke_syscall+0x74/0x260 [ +0.000009] el0_svc_common.constprop.0+0xcc/0x260 [ +0.000008] do_el0_svc+0x50/0x70 [ +0.000007] el0_svc+0x68/0x1a0 [ +0.000012] el0t_64_sync_handler+0x11c/0x150 [ +0.000008] el0t_64_sync+0x18c/0x190 [ +0.000016] Allocated by task 879: [ +0.000008] kasan_save_stack+0x2c/0x5c [ +0.000011] __kasan_kmalloc+0x90/0xd0 [ +0.000007] __kmalloc+0x278/0x4a0 [ +0.000011] mpi_resize+0x13c/0x1d0 [ +0.000011] mpi_powm+0xd24/0x1570 [ +0.000009] rsa_enc+0x1a4/0x30c [ +0.000009] pkcs1pad_verify+0x3f0/0x580 [ +0.000009] public_key_verify_signature+0x7a8/0xba4 [ +0.000010] public_key_verify_signature_2+0x40/0x60 [ +0.000008] verify_signature+0xb4/0x114 [ +0.000008] pkcs7_validate_trust_one.constprop.0+0x3b8/0x574 [ +0.000009] pkcs7_validate_trust+0xb8/0x15c [ +0.000008] verify_pkcs7_message_sig+0xec/0x1b0 [ +0.000012] verify_pkcs7_signature+0x78/0xac [ +0.000007] mod_verify_sig+0x110/0x190 [ +0.000009] module_sig_check+0x114/0x1e0 [ +0.000009] load_module+0xa0/0x1ea4 [ +0.000008] __do_sys_init_module+0x184/0x1cc [ +0.000008] __arm64_sys_init_module+0x78/0xb0 [ +0.000008] invoke_syscall+0x74/0x260 [ +0.000009] el0_svc_common.constprop.0+0x1a8/0x260 [ +0.000008] do_el0_svc+0x50/0x70 [ +0.000007] el0_svc+0x68/0x1a0 [ +0.000009] el0t_64_sync_handler+0x11c/0x150 [ +0.000009] el0t_64 ---truncated---

Quoted source text, attributed separately from HOL analysis.