CVE-2022-49552

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix combination of jit blinding and pointers to bpf subprogs.

The combination of jit blinding and pointers to bpf subprogs causes:

[ 36.989548] BUG: unable to handle page fault for address: 0000000100000001

[ 36.990342] #PF: supervisor instruction fetch in kernel mode

[ 36.990968] #PF: error_code(0x0010) - not-present page

[ 36.994859] RIP: 0010:0x100000001

[ 36.995209] Code: Unable to access opcode bytes at RIP 0xffffffd7.

[ 37.004091] Call Trace:

[ 37.004351] <TASK>

[ 37.004576] ? bpf_loop+0x4d/0x70

[ 37.004932] ? bpf_prog_3899083f75e4c5de_F+0xe3/0x13b

The jit blinding logic didn't recognize that ld_imm64 with an address

of bpf subprogram is a special instruction and proceeded to randomize it.

By itself it wouldn't have been an issue, but jit_subprogs() logic

relies on two step process to JIT all subprogs and then JIT them

again when addresses of all subprogs are known.

Blinding process i

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References