bpf: Disallow interpreter fallback for BPF_ADDR_PERCPU insn
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 7.2.6
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Disallow interpreter fallback for BPF_ADDR_PERCPU insn The BPF_MOV64_PERCPU_REG insn requires JIT to emit native code to for 'dst_reg = src_reg + <percpu_base_off>'. However, the interpreter ignores the 'off' at its ALU64_MOV_X label. The 'off' indicates the insn is BPF_MOV64_PERCPU_REG insn. Then, when the interpreter loads memory from the register, it will hit a page fault. [ 2.545572] BUG: unable to handle page fault for address: ffffffffacaaf034 [ 2.546485] #PF: supervisor read access in kernel mode [ 2.547167] #PF: error_code(0x0000) - not-present page [ 2.547850] PGD 134e63067 P4D 134e63067 PUD 134e64063 PMD 10021c063 PTE 800ffffeca550062 [ 2.548912] Oops: Oops: 0000 [#1] SMP PTI Set jit_required as true in order to disallow interpreter fallback in core.c::__bpf_prog_select_runtime(), if any BPF_ADDR_PERCPU insn is patched to the prog. BTW, rename the helper bpf_map_supports_cpu_flags() to bpf_map_is_percpu_map().
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 7bdbf7446305cb65c510c16d57cde82bc76b234a · fixed in 57cf929a33cb76be3f24886073ae820b4c496914; From 7bdbf7446305cb65c510c16d57cde82bc76b234a · fixed in 7a0855e73757ee9cf25ba635a1c735018ecba742
- Linux Linux
6.10
- KernelLinux
From 6.10.0 · fixed in 7.2.6