| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-48755: powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48755 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.8 with commit 156d0e290e969caba25f1851c52417c14d141b24 and fixed in 5.10.96 with commit 129c71829d7f46423d95c19e8d87ce956d4c6e1c |
| Issue introduced in 4.8 with commit 156d0e290e969caba25f1851c52417c14d141b24 and fixed in 5.15.19 with commit 3bfbc00587dc883eaed383558ae512a351c2cd09 |
| Issue introduced in 4.8 with commit 156d0e290e969caba25f1851c52417c14d141b24 and fixed in 5.16.5 with commit aaccfeeee1630b155e8ff0d6c449d3de1ef86e73 |
| Issue introduced in 4.8 with commit 156d0e290e969caba25f1851c52417c14d141b24 and fixed in 5.17 with commit 3f5f766d5f7f95a69a630da3544a1a0cee1cdddf |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2022-48755 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| arch/powerpc/include/asm/ppc-opcode.h |
| arch/powerpc/net/bpf_jit_comp64.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| 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 |
