You are viewing this page in an unauthorized frame window.
This is a potential security issue, you are being redirected to
https://nvd.nist.gov
An official website of the United States government
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
This CVE record has been updated after NVD enrichment efforts were completed. Enrichment data supplied by the NVD may require amendment due to these changes.
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."
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
By selecting these links, you will be leaving NIST webspace.
We have provided these links to other web sites because they
may have information that would be of interest to you. No
inferences should be drawn on account of other sites being
referenced, or not, from this page. There may be other web
sites that are more appropriate for your purpose. NIST does
not necessarily endorse the views expressed, or concur with
the facts presented on these sites. Further, NIST does not
endorse any commercial products that may be mentioned on
these sites. Please address comments about this page to [email protected].
OR
*cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
Added
CPE Configuration
OR
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.215
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.27
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.274
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.8.6
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.86
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.155
*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 4.19.312
New CVE Received from kernel.org5/19/2024 7:15:50 AM
Action
Type
Old Value
New Value
Added
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."
) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
