| ID |
CVE-2026-98132
|
| Sažetak |
In the Linux kernel, the following vulnerability has been resolved:
bpf: don't downgrade half-dead scalar zero spills to STACK_ZERO
states.c:__clean_func_state() can downgrade scalar zero spill to
STACK_ZERO in the following case:
*(u64 *)(r10 - 8) = 0;
... checkpoint ...
r1 = *(u32 *)(r10 - 4);
... no reads from r10-8 ...
Here 4 bytes at r10-8 are dead and verifier changes scalar spill to a
combination: 0000pppp (p stands for poison). Such a change breaks
precision propagation chains. All places that produce STACK_ZERO
should call bpf_mark_chain_precision() for the zero source.
This patch fixes the bug in a simplest way possible:
avoids converting stack spills of zero to STACK_ZERO.
Two smarter approaches are possible:
- do bpf_mark_chain_precision() from __clean_func_state()
- check slot liveness information in check_stack_write_fixed_off()
I investigated both and the changes required are a bit tricky,
hence go with a simple fix for the time being. |
| Reference |
|
| CVSS |
| Base: | 0.0 |
| Impact: | None |
| Exploitability: | None |
|
| Pristup |
| Vektor | Složenost | Autentikacija |
| None |
None |
None |
|
| Impact |
| Povjerljivost | Cjelovitost | Dostupnost |
| None |
None |
None |
|
| CVSS vektor |
None |
| Zadnje važnije ažuriranje |
25-09-2026 - 11:17 |
| Objavljeno |
25-09-2026 - 11:17 |
