Description
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 products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
fb7cefabae8117c203155ef169a386bec43bbba9 to < 26d9496c826586338d1b8c27edfec4a19a89f462affectedfb7cefabae8117c203155ef169a386bec43bbba9 to < 08fe2eaa609180c1baeb76c2629a9c82263b0427affectedfb7cefabae8117c203155ef169a386bec43bbba9 to < 5eb8921371c6fd117d4a328b6053dfda38707df8affected
Linux Linux
Default version status: affected
6.18affected0 to < 6.18unaffected6.18.52 to ≤ 6.18.*unaffected7.2.6 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected