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Fencer Vulns
no cvss —

CVE-2022-50628 json

drm/gud: Fix UBSAN warning

published 2025-12-08 11 mo ago modified 2026-06-17 4 mo ago also EUVD-2022-55684

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

drm/gud: Fix UBSAN warning

UBSAN complains about invalid value for bool:

[ 101.165172] [drm] Initialized gud 1.0.0 20200422 for 2-3.2:1.0 on minor 1 [ 101.213360] gud 2-3.2:1.0: [drm] fb1: guddrmfb frame buffer device [ 101.213426] usbcore: registered new interface driver gud [ 101.989431] ================================================================================ [ 101.989441] UBSAN: invalid-load in linux/include/linux/iosys-map.h:253:9 [ 101.989447] load of value 121 is not a valid value for type '_Bool' [ 101.989451] CPU: 1 PID: 455 Comm: kworker/1:6 Not tainted 5.18.0-rc5-gud-5.18-rc5 #3 [ 101.989456] Hardware name: Hewlett-Packard HP EliteBook 820 G1/1991, BIOS L71 Ver. 01.44 04/12/2018 [ 101.989459] Workqueue: events_long gud_flush_work [gud] [ 101.989471] Call Trace: [ 101.989474] <TASK> [ 101.989479] dump_stack_lvl+0x49/0x5f [ 101.989488] dump_stack+0x10/0x12 [ 101.989493] ubsan_epilogue+0x9/0x3b [ 101.989498] __ubsan_handle_load_invalid_value.cold+0x44/0x49 [ 101.989504] dma_buf_vmap.cold+0x38/0x3d [ 101.989511] ? find_busiest_group+0x48/0x300 [ 101.989520] drm_gem_shmem_vmap+0x76/0x1b0 [drm_shmem_helper] [ 101.989528] drm_gem_shmem_object_vmap+0x9/0xb [drm_shmem_helper] [ 101.989535] drm_gem_vmap+0x26/0x60 [drm] [ 101.989594] drm_gem_fb_vmap+0x47/0x150 [drm_kms_helper] [ 101.989630] gud_prep_flush+0xc1/0x710 [gud] [ 101.989639] ? _raw_spin_lock+0x17/0x40 [ 101.989648] gud_flush_work+0x1e0/0x430 [gud] [ 101.989653] ? __switch_to+0x11d/0x470 [ 101.989664] process_one_work+0x21f/0x3f0 [ 101.989673] worker_thread+0x200/0x3e0 [ 101.989679] ? rescuer_thread+0x390/0x390 [ 101.989684] kthread+0xfd/0x130 [ 101.989690] ? kthread_complete_and_exit+0x20/0x20 [ 101.989696] ret_from_fork+0x22/0x30 [ 101.989706] </TASK> [ 101.989708] ================================================================================

The source of this warning is in iosys_map_clear() called from dma_buf_vmap(). It conditionally sets values based on map->is_iomem. The iosys_map variables are allocated uninitialized on the stack leading to ->is_iomem having all kinds of values and not only 0/1.

Fix this by zeroing the iosys_map variables.

Patch / fix

  • Linux Linux 6.1.16, 6.2.3, 6.3
  • linux Debian 14, Debian 13, Debian 12 6.1.20-1

debian advisories DEBIAN-CVE-2022-50628

  • kernel RHEL 8 4.18.0-513.5.1.el8_9
  • perf RHEL 8 4.18.0-513.5.1.el8_9
  • bpftool RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-core RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-tools RHEL 8 4.18.0-513.5.1.el8_9
  • python3-perf RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-modules RHEL 8 4.18.0-513.5.1.el8_9
  • kernel-zfcpdump RHEL 8 4.18.0-513.5.1.el8_9

red hat advisories RHSA-2023:7077RHSA-2023:6583

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-50628 updated cvss 3.3

kernel: drm/gud: Fix UBSAN warning

  • Red Hat Enterprise Linux 8 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +6 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix available “To mitigate this issue, prevent the gud module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-513.5.1.el8_9, kernel-debuginfo-common-aarch64 4.18.0-513.5.1.el8_9, kernel-debuginfo-common-ppc64le 4.18.0-513.5.1.el8_9 Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-513.5.1.el8_9, kernel 4.18.0-513.5.1.el8_9, bpftool 4.18.0-513.5.1.el8_9, kernel-core 4.18.0-513.5.1.el8_9, kernel-tools 4.18.0-513.5.1.el8_9, python3-perf 4.18.0-513.5.1.el8_9, +15 more
    fixed: vendor fix “To mitigate this issue, prevent the gud module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.” RHSA-2023:7077
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.