Amazon Linux 2023: CVE-2024-35944: Medium priority package update for kernel

Amazon Linux 2023: CVE-2024-35944: Medium priority package update for kernel

Severity

5

CVSS

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

Published

05/19/2024

Created

02/14/2025

Added

02/14/2025

Modified

02/14/2025

Description

In the Linux kernel, the following vulnerability has been resolved: VMCI: Fix memcpy() run-time warning in dg_dispatch_as_host() Syzkaller hit 'WARNING in dg_dispatch_as_host' bug. memcpy: detected field-spanning write (size 56) of single field "&dg_info->msg" at drivers/misc/vmw_vmci/vmci_datagram.c:237 (size 24) WARNING: CPU: 0 PID: 1555 at drivers/misc/vmw_vmci/vmci_datagram.c:237 dg_dispatch_as_host+0x88e/0xa60 drivers/misc/vmw_vmci/vmci_datagram.c:237 Some code commentry, based on my understanding: 544 #define VMCI_DG_SIZE(_dg) (VMCI_DG_HEADERSIZE + (size_t)(_dg)->payload_size) /// This is 24 + payload_size memcpy(&dg_info->msg, dg, dg_size); Destination = dg_info->msg ---> this is a 24 byte structure(struct vmci_datagram) Source = dg --> this is a 24 byte structure (struct vmci_datagram) Size = dg_size = 24 + payload_size {payload_size = 56-24 =32} -- Syzkaller managed to set payload_size to 32. 35 struct delayed_datagram_info { 36 struct datagram_entry *entry; 37 struct work_struct work; 38 bool in_dg_host_queue; 39 /* msg and msg_payload must be together. */ 40 struct vmci_datagram msg; 41 u8 msg_payload[]; 42 }; So those extra bytes of payload are copied into msg_payload[], a run time warning is seen while fuzzing with Syzkaller. One possible way to fix the warning is to split the memcpy() into two parts -- one -- direct assignment of msg and second taking care of payload. Gustavo quoted: "Under FORTIFY_SOURCE we should not copy data across multiple members in a structure."

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-6-1-87-99-174
• 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-2024-35944
• CVE - 2024-35944
• https://alas.aws.amazon.com/AL2023/ALAS-2024-613.html