bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode
syzbot reported uninit memory usages during map_{lookup,delete}_elem.
==========
BUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
BUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
__dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline]
bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38
___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997
__bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237
==========
The reproducer should be in the interpreter mode.
The C reproducer is trying to run the following bpf prog:
0: (18) r0 = 0x0
2: (18) r1 = map[id:49]
4: (b7) r8 = 16777216
5: (7b) *(u64 *)(r10 -8) = r8
6: (bf) r2 = r10
7: (07) r2 += -229
^^^^^^^^^^
8: (b7) r3 = 8
9: (b7) r4 = 0
10: (85) call dev_map_lookup_elem#1543472
11: (95) exit
It is due to the "void *key" (r2) passed to the helper. bpf allows uninit
stack memory access for bpf prog with the right privileges. This patch
uses kmsan_unpoison_memory() to mark the stack as initialized.
This should address different syzbot reports on the uninit "void *key"
argument during map_{lookup,delete}_elem.
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4008-1 | linux-6.1 security update |
Ubuntu USN |
USN-7089-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-5 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-6 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7089-7 | Linux kernel (Low Latency) vulnerabilities |
Ubuntu USN |
USN-7090-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7095-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7156-1 | Linux kernel (GKE) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 03 Nov 2025 22:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 11 Sep 2024 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Thu, 05 Sep 2024 18:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-908 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Mon, 19 Aug 2024 22:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-120 | |
| Metrics |
cvssV3_1
|
cvssV3_1
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T22:01:03.937Z
Reserved: 2024-07-29T15:50:41.166Z
Link: CVE-2024-42063
Updated: 2024-08-02T04:54:31.920Z
Status : Modified
Published: 2024-07-29T16:15:06.053
Modified: 2025-11-03T22:17:34.690
Link: CVE-2024-42063
OpenCVE Enrichment
No data.
Debian DLA
Ubuntu USN