Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject non-negative offsets in stack_slot_obj_get_spi() bpf_get_spi() computes (-off - 1) / BPF_REG_SIZE using C division, which truncates toward zero. For off == 0, this produces spi 0, the same index used by the valid stack slot at fp-8. stack_slot_obj_get_spi() currently checks alignment and the resulting spi bounds, but does not reject the non-negative offset itself. It can therefore validate a PTR_TO_STACK register holding fp+0 against an iterator stored at fp-8 even though the runtime receives the actual fp+0 pointer. An effectful iterator kfunc can then interpret memory outside the BPF stack as iterator state. Reject non-negative offsets before converting the offset to an spi. All valid stack objects begin at a negative offset from the frame pointer.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 06accc8779c1d558a5b5a21f2ac82b0c95827ddd before 89a7241fc7ecc1b5e47c3f071081e314523b8d9d; affected 06accc8779c1d558a5b5a21f2ac82b0c95827ddd before 79a9172f3ab4ad8392c5e5c8944b9b7710ade620 |
| Linux / Linux | affected 6.4; unaffected 0 before 6.4; unaffected 7.2.9 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.