Bug 2347947 (CVE-2022-49552) - CVE-2022-49552 kernel: bpf: Fix combination of jit blinding and pointers to bpf subprogs.
Summary: CVE-2022-49552 kernel: bpf: Fix combination of jit blinding and pointers to b...
Keywords:
Status: NEW
Alias: CVE-2022-49552
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-02-26 03:12 UTC by OSIDB Bzimport
Modified: 2025-02-27 23:15 UTC (History)
4 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2025-02-26 03:12:18 UTC
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 in the first JIT phase caused second JIT to miss
adjustment of special ld_imm64.

Fix this issue by ignoring special ld_imm64 instructions that don't have
user controlled constants and shouldn't be blinded.

Comment 3 Avinash Hanwate 2025-02-27 23:10:58 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022616-CVE-2022-49552-e30f@gregkh/T


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