// For flags

CVE-2023-53825

kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg().

Severity Score

5.5
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved: kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg(). syzkaller found a memory leak in kcm_sendmsg(), and commit c821a88bd720
("kcm: Fix memory leak in error path of kcm_sendmsg()") suppressed it by
updating kcm_tx_msg(head)->last_skb if partial data is copied so that the
following sendmsg() will resume from the skb. However, we cannot know how many bytes were copied when we get the error.
Thus, we could mess up the MSG_MORE queue. When kcm_sendmsg() fails for SOCK_DGRAM, we should purge the queue as we
do so for UDP by udp_flush_pending_frames(). Even without this change, when the error occurred, the following sendmsg()
resumed from a wrong skb and the queue was messed up. However, we have
yet to get such a report, and only syzkaller stumbled on it. So, this
can be changed safely. Note this does not change SOCK_SEQPACKET behaviour.

In the Linux kernel, the following vulnerability has been resolved: kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg(). syzkaller found a memory leak in kcm_sendmsg(), and commit c821a88bd720 ("kcm: Fix memory leak in error path of kcm_sendmsg()") suppressed it by updating kcm_tx_msg(head)->last_skb if partial data is copied so that the following sendmsg() will resume from the skb. However, we cannot know how many bytes were copied when we get the error. Thus, we could mess up the MSG_MORE queue. When kcm_sendmsg() fails for SOCK_DGRAM, we should purge the queue as we do so for UDP by udp_flush_pending_frames(). Even without this change, when the error occurred, the following sendmsg() resumed from a wrong skb and the queue was messed up. However, we have yet to get such a report, and only syzkaller stumbled on it. So, this can be changed safely. Note this does not change SOCK_SEQPACKET behaviour.

The SUSE Linux Enterprise 15 SP6 kernel was updated to fix various security issues.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2025-12-09 CVE Reserved
  • 2025-12-09 CVE Published
  • 2026-05-08 EPSS Updated
  • 2026-05-11 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 4.14.326
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 4.14.326"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 4.19.295
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 4.19.295"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 5.4.257
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 5.4.257"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 5.10.195
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 5.10.195"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 5.15.132
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 5.15.132"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 6.1.54
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.1.54"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 6.5.4
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.5.4"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 4.6 < 6.6
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.6"
en
Affected