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Fencer Vulns
high 7.1

CVE-2022-50231 json

crypto: arm64/poly1305 - fix a read out-of-bound

published 2025-06-18 16 mo ago modified 2026-08-05 3 mo ago also EUVD-2022-55489

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

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

crypto: arm64/poly1305 - fix a read out-of-bound

A kasan error was reported during fuzzing:

BUG: KASAN: slab-out-of-bounds in neon_poly1305_blocks.constprop.0+0x1b4/0x250 [poly1305_neon] Read of size 4 at addr ffff0010e293f010 by task syz-executor.5/1646715 CPU: 4 PID: 1646715 Comm: syz-executor.5 Kdump: loaded Not tainted 5.10.0.aarch64 #1 Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.59 01/31/2019 Call trace: dump_backtrace+0x0/0x394 show_stack+0x34/0x4c arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x158/0x1e4 lib/dump_stack.c:118 print_address_description.constprop.0+0x68/0x204 mm/kasan/report.c:387 __kasan_report+0xe0/0x140 mm/kasan/report.c:547 kasan_report+0x44/0xe0 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load4+0x94/0xd0 mm/kasan/generic.c:252 neon_poly1305_blocks.constprop.0+0x1b4/0x250 [poly1305_neon] neon_poly1305_do_update+0x6c/0x15c [poly1305_neon] neon_poly1305_update+0x9c/0x1c4 [poly1305_neon] crypto_shash_update crypto/shash.c:131 [inline] shash_finup_unaligned+0x84/0x15c crypto/shash.c:179 crypto_shash_finup+0x8c/0x140 crypto/shash.c:193 shash_digest_unaligned+0xb8/0xe4 crypto/shash.c:201 crypto_shash_digest+0xa4/0xfc crypto/shash.c:217 crypto_shash_tfm_digest+0xb4/0x150 crypto/shash.c:229 essiv_skcipher_setkey+0x164/0x200 [essiv] crypto_skcipher_setkey+0xb0/0x160 crypto/skcipher.c:612 skcipher_setkey+0x3c/0x50 crypto/algif_skcipher.c:305 alg_setkey+0x114/0x2a0 crypto/af_alg.c:220 alg_setsockopt+0x19c/0x210 crypto/af_alg.c:253 __sys_setsockopt+0x190/0x2e0 net/socket.c:2123 __do_sys_setsockopt net/socket.c:2134 [inline] __se_sys_setsockopt net/socket.c:2131 [inline] __arm64_sys_setsockopt+0x78/0x94 net/socket.c:2131 __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] invoke_syscall+0x64/0x100 arch/arm64/kernel/syscall.c:48 el0_svc_common.constprop.0+0x220/0x230 arch/arm64/kernel/syscall.c:155 do_el0_svc+0xb4/0xd4 arch/arm64/kernel/syscall.c:217 el0_svc+0x24/0x3c arch/arm64/kernel/entry-common.c:353 el0_sync_handler+0x160/0x164 arch/arm64/kernel/entry-common.c:369 el0_sync+0x160/0x180 arch/arm64/kernel/entry.S:683

This error can be reproduced by the following code compiled as ko on a system with kasan enabled:

#include <linux/module.h> #include <linux/crypto.h> #include <crypto/hash.h> #include <crypto/poly1305.h>

char test_data[] = "\x00\x01\x02\x03\x04\x05\x06\x07" "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" "\x10\x11\x12\x13\x14\x15\x16\x17" "\x18\x19\x1a\x1b\x1c\x1d\x1e";

int init(void) { struct crypto_shash *tfm = NULL; char *data = NULL, *out = NULL;

tfm = crypto_alloc_shash("poly1305", 0, 0); data = kmalloc(POLY1305_KEY_SIZE - 1, GFP_KERNEL); out = kmalloc(POLY1305_DIGEST_SIZE, GFP_KERNEL); memcpy(data, test_data, POLY1305_KEY_SIZE - 1); crypto_shash_tfm_digest(tfm, data, POLY1305_KEY_SIZE - 1, out);

kfree(data); kfree(out); return 0; }

void deinit(void) { }

module_init(init) module_exit(deinit) MODULE_LICENSE("GPL");

The root cause of the bug sits in neon_poly1305_blocks. The logic neon_poly1305_blocks() performed is that if it was called with both s[] and r[] uninitialized, it will first try to initialize them with the data from the first "block" that it believed to be 32 bytes in length. First 16 bytes are used as the key and the next 16 bytes for s[]. This would lead to the aforementioned read out-of-bound. However, after calling poly1305_init_arch(), only 16 bytes were deducted from the input and s[] is initialized yet again with the following 16 bytes. The second initialization of s[] is certainly redundent which indicates that the first initialization should be for r[] only.

This patch fixes the issue by calling poly1305_init_arm64() instead o ---truncated---

Patch / fix

  • Linux Linux 5.10.136, 5.15.60, 5.18.17, 5.19.1, 6.0
  • linux Debian 14, Debian 13, Debian 12 6.0.2-1

debian advisories DEBIAN-CVE-2022-50231

  • linux Ubuntu 22.04 LTS 5.15.0-50.56
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1021.25
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1019.25
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1017.20
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1015.17
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1019.23
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1021.26
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1004.6

ubuntu advisories UBUNTU-CVE-2022-50231

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.170.2
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.170.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.170.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +6 more 5.14.21-150400.24.170.2
  • kernel-zfcpdump SLES 15 SP4-LTSS, Manager Server 4.3 5.14.21-150400.24.170.2
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.170.2
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.170.2.150400.24.86.2
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.124.1

suse advisories SUSE-SU-2025:02537-1SUSE-SU-2025:02322-1SUSE-SU-2025:02321-1SUSE-SU-2025:02320-1SUSE-SU-2025:02308-1SUSE-SU-2025:02264-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-50231 updated cvss 6.1

kernel: Linux kernel: Denial of service or information disclosure in arm64/poly1305 due to out-of-bounds read

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
NVD 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

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