Amazon Linux 2023: CVE-2024-42063: Medium priority package update for kernel (Multiple Advisories)

Amazon Linux 2023: CVE-2024-42063: Medium priority package update for kernel (Multiple Advisories)

Severity

4

CVSS

(AV:L/AC:L/Au:M/C:N/I:N/A:C)

Published

07/29/2024

Created

02/14/2025

Added

02/14/2025

Modified

02/14/2025

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode syzbot reported uninit memory usages during map_{lookup,delete}_elem. ========== BUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline] BUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796 __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline] dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796 ____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline] bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38 ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 __bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237 ========== The reproducer should be in the interpreter mode. The C reproducer is trying to run the following bpf prog: 0: (18) r0 = 0x0 2: (18) r1 = map[id:49] 4: (b7) r8 = 16777216 5: (7b) *(u64 *)(r10 -8) = r8 6: (bf) r2 = r10 7: (07) r2 += -229 ^^^^^^^^^^ 8: (b7) r3 = 8 9: (b7) r4 = 0 10: (85) call dev_map_lookup_elem#1543472 11: (95) exit It is due to the "void *key" (r2) passed to the helper. bpf allows uninit stack memory access for bpf prog with the right privileges. This patch uses kmsan_unpoison_memory() to mark the stack as initialized. This should address different syzbot reports on the uninit "void *key" argument during map_{lookup,delete}_elem.

Solution(s)

• amazon-linux-2023-upgrade-bpftool
• amazon-linux-2023-upgrade-bpftool-debuginfo
• amazon-linux-2023-upgrade-kernel
• amazon-linux-2023-upgrade-kernel-debuginfo
• amazon-linux-2023-upgrade-kernel-debuginfo-common-aarch64
• amazon-linux-2023-upgrade-kernel-debuginfo-common-x86-64
• amazon-linux-2023-upgrade-kernel-devel
• amazon-linux-2023-upgrade-kernel-headers
• amazon-linux-2023-upgrade-kernel-libbpf
• amazon-linux-2023-upgrade-kernel-libbpf-devel
• amazon-linux-2023-upgrade-kernel-libbpf-static
• amazon-linux-2023-upgrade-kernel-livepatch-6-1-97-104-177
• amazon-linux-2023-upgrade-kernel-modules-extra
• amazon-linux-2023-upgrade-kernel-modules-extra-common
• amazon-linux-2023-upgrade-kernel-tools
• amazon-linux-2023-upgrade-kernel-tools-debuginfo
• amazon-linux-2023-upgrade-kernel-tools-devel
• amazon-linux-2023-upgrade-perf
• amazon-linux-2023-upgrade-perf-debuginfo
• amazon-linux-2023-upgrade-python3-perf
• amazon-linux-2023-upgrade-python3-perf-debuginfo

References

• https://attackerkb.com/topics/cve-2024-42063
• CVE - 2024-42063
• https://alas.aws.amazon.com/AL2023/ALAS-2024-665.html
• https://alas.aws.amazon.com/AL2023/ALAS-2024-714.html