CVE-2025-21866
March 13, 2025, 9:13 p.m.
5.5
Medium
Description
In the Linux kernel, the following vulnerability has been resolved:
powerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC
Erhard reported the following KASAN hit while booting his PowerMac G4
with a KASAN-enabled kernel 6.13-rc6:
BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8
Write of size 8 at addr f1000000 by task chronyd/1293
CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G W 6.13.0-rc6-PMacG4 #2
Tainted: [W]=WARN
Hardware name: PowerMac3,6 7455 0x80010303 PowerMac
Call Trace:
[c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable)
[c24375b0] [c0504998] print_report+0xdc/0x504
[c2437610] [c050475c] kasan_report+0xf8/0x108
[c2437690] [c0505a3c] kasan_check_range+0x24/0x18c
[c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8
[c24376c0] [c004c014] patch_instructions+0x15c/0x16c
[c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c
[c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac
[c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec
[c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478
[c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14
[c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4
[c24379d0] [c027111c] do_seccomp+0x3dc/0x1890
[c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420
[c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c
--- interrupt: c00 at 0x5a1274
NIP: 005a1274 LR: 006a3b3c CTR: 005296c8
REGS: c2437f40 TRAP: 0c00 Tainted: G W (6.13.0-rc6-PMacG4)
MSR: 0200f932 <VEC,EE,PR,FP,ME,IR,DR,RI> CR: 24004422 XER: 00000000
GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932
GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57
GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002
GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001
NIP [005a1274] 0x5a1274
LR [006a3b3c] 0x6a3b3c
--- interrupt: c00
The buggy address belongs to the virtual mapping at
[f1000000, f1002000) created by:
text_area_cpu_up+0x20/0x190
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30
flags: 0x80000000(zone=2)
raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001
raw: 00000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>f1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================
f8 corresponds to KASAN_VMALLOC_INVALID which means the area is not
initialised hence not supposed to be used yet.
Powerpc text patching infrastructure allocates a virtual memory area
using get_vm_area() and flags it as VM_ALLOC. But that flag is meant
to be used for vmalloc() and vmalloc() allocated memory is not
supposed to be used before a call to __vmalloc_node_range() which is
never called for that area.
That went undetected until commit e4137f08816b ("mm, kasan, kmsan:
instrument copy_from/to_kernel_nofault")
The area allocated by text_area_cpu_up() is not vmalloc memory, it is
mapped directly on demand when needed by map_kernel_page(). There is
no VM flag corresponding to such usage, so just pass no flag. That way
the area will be unpoisonned and usable immediately.
Product(s) Impacted
Vendor | Product | Versions |
---|---|---|
Linux |
|
|
Weaknesses
CWE-770
Allocation of Resources Without Limits or Throttling
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.
*CPE(s)
Type | Vendor | Product | Version | Update | Edition | Language | Software Edition | Target Software | Target Hardware | Other Information |
---|---|---|---|---|---|---|---|---|---|---|
o | linux | linux_kernel | / | / | / | / | / | / | / | / |
o | linux | linux_kernel | / | / | / | / | / | / | / | / |
o | linux | linux_kernel | / | / | / | / | / | / | / | / |
o | linux | linux_kernel | / | / | / | / | / | / | / | / |
o | linux | linux_kernel | 6.14 | rc1 | / | / | / | / | / | / |
o | linux | linux_kernel | 6.14 | rc2 | / | / | / | / | / | / |
o | linux | linux_kernel | 6.14 | rc3 | / | / | / | / | / | / |
References
Tags
CVSS Score
CVSS Data
- Attack Vector: LOCAL
- Attack Complexity: LOW
- Privileges Required: LOW
- Scope: UNCHANGED
- Confidentiality Impact: NONE
- Integrity Impact: NONE
- Availability Impact: HIGH
View Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Date
- Published: March 12, 2025, 10:15 a.m.
- Last Modified: March 13, 2025, 9:13 p.m.
Status : Analyzed
CVE is currently being analyzed by NVD staff, this process results in association of reference link tags, CVSS scores, CWE association, and CPE applicability statements.
More infoSource
416baaa9-dc9f-4396-8d5f-8c081fb06d67
*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.