Homepage

CVE-2024-35944 Affecting perf package, versions <0:6.1.87-99.174.amzn2023

Severity

 Recommended
0.0
medium
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.04% (15th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-AMZN2023-PERF-8494905
  • published11 Dec 2024
  • disclosed19 May 2024
Report a new vulnerability Found a mistake?

Introduced: 19 May 2024

CVE-2024-35944  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 perf to version 0:6.1.87-99.174.amzn2023 or higher.
This issue was patched in ALAS2023-2024-613.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perf package and not the perf package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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."

CVSS Scores

version 3.1