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Rocky Linux: CVE-2024-35944: kernel-rt (RLSA-2024-7001)

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Rocky Linux: CVE-2024-35944: kernel-rt (RLSA-2024-7001)

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
05/19/2024
Created
10/03/2024
Added
10/02/2024
Modified
10/02/2024

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)

  • rocky-upgrade-kernel-rt
  • rocky-upgrade-kernel-rt-core
  • rocky-upgrade-kernel-rt-debug
  • rocky-upgrade-kernel-rt-debug-core
  • rocky-upgrade-kernel-rt-debug-debuginfo
  • rocky-upgrade-kernel-rt-debug-devel
  • rocky-upgrade-kernel-rt-debug-kvm
  • rocky-upgrade-kernel-rt-debug-modules
  • rocky-upgrade-kernel-rt-debug-modules-extra
  • rocky-upgrade-kernel-rt-debuginfo
  • rocky-upgrade-kernel-rt-debuginfo-common-x86_64
  • rocky-upgrade-kernel-rt-devel
  • rocky-upgrade-kernel-rt-kvm
  • rocky-upgrade-kernel-rt-modules
  • rocky-upgrade-kernel-rt-modules-extra

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