Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: bpf, riscv: Fix extable handling for arena load_acquire emit_atomic_ld_st() returns 1 to have build_body() skip the zext after a sub-word load_acquire. The caller does "ret = ret ?: add_exception_handler(...)", which skips add_exception_handler() on any non-zero ret, so the extable entry is missing and a faulting PROBE_ATOMIC load_acquire oopses. REG_DONT_CLEAR_MARKER leaves rd stale on fault, and the verifier still thinks the load overwrote it, so a program can leak it through a map. Check ret >= 0 before calling add_exception_handler(), and pass rd for LOAD_ACQ so the fault zeroes rd like a PROBE_MEM load. Return ret unchanged for the zext skip.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected fb7cefabae8117c203155ef169a386bec43bbba9 before 26d9496c826586338d1b8c27edfec4a19a89f462; affected fb7cefabae8117c203155ef169a386bec43bbba9 before 08fe2eaa609180c1baeb76c2629a9c82263b0427; affected fb7cefabae8117c203155ef169a386bec43bbba9 before 5eb8921371c6fd117d4a328b6053dfda38707df8 |
| Linux / Linux | affected 6.18; unaffected 0 before 6.18; unaffected 6.18.52 through 6.18.*; unaffected 7.2.6 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.