CVE-2022-48755

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 Johan reported the below crash with test_bpf on ppc64 e5500: test_bpf: #296 ALU_END_FROM_LE 64: 0x0123456789abcdef -> 0x67452301 jited:1 Oops: Exception in kernel mode, sig: 4 [#1] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 Modules linked in: test_bpf(+) CPU: 0 PID: 76 Comm: insmod Not tainted 5.14.0-03771-g98c2059e008a-dirty #1 NIP: 8000000000061c3c LR: 80000000006dea64 CTR: 8000000000061c18 REGS: c0000000032d3420 TRAP: 0700 Not tainted (5.14.0-03771-g98c2059e008a-dirty) MSR: 0000000080089000 <EE,ME> CR: 88002822 XER: 20000000 IRQMASK: 0 <...> NIP [8000000000061c3c] 0x8000000000061c3c LR [80000000006dea64] .__run_one+0x104/0x17c [test_bpf] Call Trace: .__run_one+0x60/0x17c [test_bpf] (unreliable) .test_bpf_init+0x6a8/0xdc8 [test_bpf] .do_one_initcall+0x6c/0x28c .do_init_module+0x68/0x28c .load_module+0x2460/0x2abc .__do_sys_init_module+0x120/0x18c .system_call_exception+0x110/0x1b8 system_call_common+0xf0/0x210 --- interrupt: c00 at 0x101d0acc <...> ---[ end trace 47b2bf19090bb3d0 ]--- Illegal instruction The illegal instruction turned out to be 'ldbrx' emitted for BPF_FROM_[L|B]E, which was only introduced in ISA v2.06. Guard use of the same and implement an alternative approach for older processors.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/129c71829d7f46423d95c19e8d87ce956d4c6e1c ↗
• https://git.kernel.org/stable/c/3bfbc00587dc883eaed383558ae512a351c2cd09 ↗
• https://git.kernel.org/stable/c/aaccfeeee1630b155e8ff0d6c449d3de1ef86e73 ↗
• https://git.kernel.org/stable/c/3f5f766d5f7f95a69a630da3544a1a0cee1cdddf ↗