cbcvebase.
CVE-2024-35944
published 2024-05-19

CVE-2024-35944: 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…

PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.23%
14.2th percentile
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."

Affected

25 ranges
VendorProductVersion rangeFixed in
debiandebian_linux
debianlinux< linux 6.1.90-1 (bookworm)linux 6.1.90-1 (bookworm)
linuxlinux
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < e87bb99d2df6512d8ee37a5d63d2ca9a39a8c051e87bb99d2df6512d8ee37a5d63d2ca9a39a8c051
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < f15eca95138b3d4ec17b63c3c1937b0aa0d3624bf15eca95138b3d4ec17b63c3c1937b0aa0d3624b
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < ad78c5047dc4076d0b3c4fad4f42ffe9c86e8100ad78c5047dc4076d0b3c4fad4f42ffe9c86e8100
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < 130b0cd064874e0d0f58e18fb00e6f3993e90c74130b0cd064874e0d0f58e18fb00e6f3993e90c74
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < feacd430b42bbfa9ab3ed9e4f38b86c43e348c75feacd430b42bbfa9ab3ed9e4f38b86c43e348c75
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < dae70a57565686f16089737adb8ac64471570f73dae70a57565686f16089737adb8ac64471570f73
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < 491a1eb07c2bd8841d63cb5263455e185be5866f491a1eb07c2bd8841d63cb5263455e185be5866f
linuxlinux>= a110b7ebb9c674a2b591af2780dd512ad0198d50 < 19b070fefd0d024af3daa7329cbc0d00de5302ec19b070fefd0d024af3daa7329cbc0d00de5302ec
linuxlinux_kernel< 4.19.3124.19.312
linuxlinux_kernel>= 0 < 5.10.216-15.10.216-1
linuxlinux_kernel>= 0 < 6.1.90-16.1.90-1
linuxlinux_kernel>= 0 < 6.8.9-16.8.9-1
linuxlinux_kernel>= 0 < 6.8.9-16.8.9-1
linuxlinux_kernel>= 0 < 5.4.0-189.2095.4.0-189.209
linuxlinux_kernel>= 0 < 5.15.0-116.1265.15.0-116.126
linuxlinux_kernel>= 0 < 6.8.0-38.386.8.0-38.38
linuxlinux_kernel>= 4.20 < 5.4.2745.4.274
linuxlinux_kernel>= 5.11 < 5.15.1555.15.155
linuxlinux_kernel>= 5.16 < 6.1.866.1.86
linuxlinux_kernel>= 5.5 < 5.10.2155.10.215
linuxlinux_kernel>= 6.2 < 6.6.276.6.27
linuxlinux_kernel>= 6.7 < 6.8.66.8.6

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.0HIGH
vendor_ubuntu7.0HIGH
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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