CVE-2022-50390

  • Published: 2025-09-18T14:15:37.997

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

drm/ttm: fix undefined behavior in bit shift for TTM_TT_FLAG_PRIV_POPULATED

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in ./include/drm/ttm/ttm_tt.h:122:26
left shift of 1 by 31 places cannot be represented in type ‘int’
Call Trace:

dump_stack_lvl+0x7d/0xa5
dump_stack+0x15/0x1b
ubsan_epilogue+0xe/0x4e
__ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
ttm_bo_move_memcpy+0x3b4/0x460 [ttm]
bo_driver_move+0x32/0x40 [drm_vram_helper]
ttm_bo_handle_move_mem+0x118/0x200 [ttm]
ttm_bo_validate+0xfa/0x220 [ttm]
drm_gem_vram_pin_locked+0x70/0x1b0 [drm_vram_helper]
drm_gem_vram_pin+0x48/0xb0 [drm_vram_helper]
drm_gem_vram_plane_helper_prepare_fb+0x53/0xe0 [drm_vram_helper]
drm_gem_vram_simple_display_pipe_prepare_fb+0x26/0x30 [drm_vram_helper]
drm_simple_kms_plane_prepare_fb+0x4d/0xe0 [drm_kms_helper]
drm_atomic_helper_prepare_planes+0xda/0x210 [drm_kms_helper]
drm_atomic_helper_commit+0xc3/0x1e0 [drm_kms_helper]
drm_atomic_commit+0x9c/0x160 [drm]
drm_client_modeset_commit_atomic+0x33a/0x380 [drm]
drm_client_modeset_commit_locked+0x77/0x220 [drm]
drm_client_modeset_commit+0x31/0x60 [drm]
__drm_fb_helper_restore_fbdev_mode_unlocked+0xa7/0x170 [drm_kms_helper]
drm_fb_helper_set_par+0x51/0x90 [drm_kms_helper]
fbcon_init+0x316/0x790
visual_init+0x113/0x1d0
do_bind_con_driver+0x2a3/0x5c0
do_take_over_console+0xa9/0x270
do_fbcon_takeover+0xa1/0x170
do_fb_registered+0x2a8/0x340
fbcon_fb_registered+0x47/0xe0
register_framebuffer+0x294/0x4a0
__drm_fb_helper_initial_config_and_unlock+0x43c/0x880 [drm_kms_helper]
drm_fb_helper_initial_config+0x52/0x80 [drm_kms_helper]
drm_fbdev_client_hotplug+0x156/0x1b0 [drm_kms_helper]
drm_fbdev_generic_setup+0xfc/0x290 [drm_kms_helper]
bochs_pci_probe+0x6ca/0x772 [bochs]
local_pci_probe+0x4d/0xb0
pci_device_probe+0x119/0x320
really_probe+0x181/0x550
__driver_probe_device+0xc6/0x220
driver_probe_device+0x32/0x100
__driver_attach+0x195/0x200
bus_for_each_dev+0xbb/0x120
driver_attach+0x27/0x30
bus_add_driver+0x22e/0x2f0
driver_register+0xa9/0x190
__pci_register_driver+0x90/0xa0
bochs_pci_driver_init+0x52/0x1000 [bochs]
do_one_initcall+0x76/0x430
do_init_module+0x61/0x28a
load_module+0x1f82/0x2e50
__do_sys_finit_module+0xf8/0x190
__x64_sys_finit_module+0x23/0x30
do_syscall_64+0x58/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Related CVE by CWE

No related CWE found.

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How to fix CVE-2022-50390

CVE-2022-50390 is a unknown severity vulnerability affecting the affected product.

Description: In the Linux kernel, the following vulnerability has been resolved: drm/ttm: fix undefined behavior in bit shift for TTM_TT_FLAG_PRIV_POPULATED Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. The UBSAN warning calltrace like below: UBSAN: shift-out-of-bounds in ./include/drm/ttm/ttm_tt.h:122:26 left shift of 1 by 31 places cannot be represented in […]

Exploit Difficulty: HARD
⏱️ Time to exploit: > 4 hours
🛠️ Required skills: Advanced security expertise
💰 Public exploits: Rare or not public

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Exploit Difficulty Assessment

HARD
⏱️ Time to Exploit: > 4 hours
🛠️ Skills Required: Advanced security expertise
💰 Public Exploits: Rare or not public

Vulnerability Timeline

Sep 18, 2025
Vulnerability Published

CVE details first published to NVD database

Nov 12, 2025
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.