// For flags

CVE-2024-26940

drm/vmwgfx: Create debugfs ttm_resource_manager entry only if needed

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

drm/vmwgfx: Create debugfs ttm_resource_manager entry only if needed

The driver creates /sys/kernel/debug/dri/0/mob_ttm even when the
corresponding ttm_resource_manager is not allocated.
This leads to a crash when trying to read from this file.

Add a check to create mob_ttm, system_mob_ttm, and gmr_ttm debug file
only when the corresponding ttm_resource_manager is allocated.

crash> bt
PID: 3133409 TASK: ffff8fe4834a5000 CPU: 3 COMMAND: "grep"
#0 [ffffb954506b3b20] machine_kexec at ffffffffb2a6bec3
#1 [ffffb954506b3b78] __crash_kexec at ffffffffb2bb598a
#2 [ffffb954506b3c38] crash_kexec at ffffffffb2bb68c1
#3 [ffffb954506b3c50] oops_end at ffffffffb2a2a9b1
#4 [ffffb954506b3c70] no_context at ffffffffb2a7e913
#5 [ffffb954506b3cc8] __bad_area_nosemaphore at ffffffffb2a7ec8c
#6 [ffffb954506b3d10] do_page_fault at ffffffffb2a7f887
#7 [ffffb954506b3d40] page_fault at ffffffffb360116e
[exception RIP: ttm_resource_manager_debug+0x11]
RIP: ffffffffc04afd11 RSP: ffffb954506b3df0 RFLAGS: 00010246
RAX: ffff8fe41a6d1200 RBX: 0000000000000000 RCX: 0000000000000940
RDX: 0000000000000000 RSI: ffffffffc04b4338 RDI: 0000000000000000
RBP: ffffb954506b3e08 R8: ffff8fee3ffad000 R9: 0000000000000000
R10: ffff8fe41a76a000 R11: 0000000000000001 R12: 00000000ffffffff
R13: 0000000000000001 R14: ffff8fe5bb6f3900 R15: ffff8fe41a6d1200
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#8 [ffffb954506b3e00] ttm_resource_manager_show at ffffffffc04afde7 [ttm]
#9 [ffffb954506b3e30] seq_read at ffffffffb2d8f9f3
RIP: 00007f4c4eda8985 RSP: 00007ffdbba9e9f8 RFLAGS: 00000246
RAX: ffffffffffffffda RBX: 000000000037e000 RCX: 00007f4c4eda8985
RDX: 000000000037e000 RSI: 00007f4c41573000 RDI: 0000000000000003
RBP: 000000000037e000 R8: 0000000000000000 R9: 000000000037fe30
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4c41573000
R13: 0000000000000003 R14: 00007f4c41572010 R15: 0000000000000003
ORIG_RAX: 0000000000000000 CS: 0033 SS: 002b

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: drm/vmwgfx: cree la entrada debugfs ttm_resource_manager solo si es necesario. El controlador crea /sys/kernel/debug/dri/0/mob_ttm incluso cuando el ttm_resource_manager correspondiente no está asignado. Esto provoca un bloqueo al intentar leer este archivo. Agregue una marca para crear archivos de depuración mob_ttm, system_mob_ttm y gmr_ttm solo cuando se asigne el ttm_resource_manager correspondiente. crash> bt PID: 3133409 TAREA: ffff8fe4834a5000 CPU: 3 COMANDO: "grep" #0 [ffffb954506b3b20] machine_kexec en ffffffffb2a6bec3 #1 [ffffb954506b3b78] __crash_kexec en ffffffffb2bb598a #2 ffb954506b3c38] crash_kexec en ffffffffb2bb68c1 #3 [ffffb954506b3c50] oops_end en ffffffffb2a2a9b1 # 4 [ffffb954506b3c70] no_context en ffffffffb2a7e913 #5 [ffffb954506b3cc8] __bad_area_nosemaphore en ffffffffb2a7ec8c #6 [ffffb954506b3d10] do_page_fault en ffffffffb2a7f887 #7 54506b3d40] page_fault en ffffffffb360116e [excepción RIP: ttm_resource_manager_debug+0x11] RIP: ffffffffc04afd11 RSP: ffffb954506b3df0 RFLAGS: 00010246 RAX: ffff8fe41a6d1200 RBX: 0000000000000000 RCX: 0000000000000940 RDX: 0000000000000000 RSI: ffffffffc04b4338 RDI: 0000000000000000 RBP: ffffb9545 06b3e08 R8: ffff8fee3ffad000 R9: 0000000000000000 R10: ffff8fe41a76a000 R11: 0000000000000001 R12: 00000000ffffffff R13: 0000000000000001 R14: ffff8fe5bb6f3900 R15: ffff8fe41a6d1200 ORIG_RAX: ffffffffffffff CS: 0010 SS : 0018 #8 [ffffb954506b3e00] ttm_resource_manager_show en ffffffffc04afde7 [ttm] #9 [ffffb954506b3e30] seq_read en ffffffffb2d8f9f3 RIP: 00007f4c4eda8985 RSP: RFLAGS: 00000246 RAX: ffffffffffffffda RBX: 000000000037e000 RCX: 00007f4c4eda8985 RDX: 000000000037e000 RSI: 00007f4c41573000 RDI: 00000000000000 03 PBR: 000000000037e000 R8: 0000000000000000 R9: 000000000037fe30 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4c41573000 R13: 0000000000000003 R14: 00007f4c41572010 R15: 0000000000000003 ORIG_RAX: 0000000000000000 CS: 0033 SS: 002b

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-02-19 CVE Reserved
  • 2024-05-01 CVE Published
  • 2024-05-01 EPSS Updated
  • 2024-08-02 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.19 < 6.1.84
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.1.84"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.19 < 6.6.24
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.6.24"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.19 < 6.7.12
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.7.12"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.19 < 6.8.3
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.8.3"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.19 < 6.9
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.9"
en
Affected