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

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---

Published: 2025-09-15 Last update: 2025-11-25 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-50256 is rated Low Risk (32.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-50256

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-09-16 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-50256

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2022-50256

OS Trackers for CVE-2022-50256

vendor priority summary link
debian not yet assigned CVE-2022-50256 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2022-50256
redhat — — https://access.redhat.com/security/cve/CVE-2022-50256
suse medium CVE-2022-50256 severity moderate: SUSE including 25 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 268 product×package rows across 54 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (54 product lines)): Known Not Affected 268. https://www.suse.com/security/cve/CVE-2022-50256/
ubuntu medium CVE-2022-50256 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 162, released 88, needed 75, not-affected 72. https://ubuntu.com/security/CVE-2022-50256

Affected software / configurations for CVE-2022-50256

Vendor Product Version Raw CPE
linux linux_kernel >= 4.10, < 5.19.17 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.0, < 6.0.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2022-50256

cvelogic Threat Intelligence