In the Linux kernel, the following vulnerability has been resolved:

ksmbd: ipc: fix use-after-free in ipc_msg_send_request

ipc_msg_send_request() waits for a generic netlink reply using an
ipc_msg_table_entry on the stack. The generic netlink handler
(handle_generic_event()/handle_response()) fills entry->response under
ipc_msg_table_lock, but ipc_msg_send_request() used to validate and free
entry->response without holding the same lock.

Under high concurrency this allows a race where handle_response() is
copying data into entry->response while ipc_msg_send_request() has just
freed it, leading to a slab-use-after-free reported by KASAN in
handle_generic_event():

BUG: KASAN: slab-use-after-free in handle_generic_event+0x3c4/0x5f0 [ksmbd]
Write of size 12 at addr ffff888198ee6e20 by task pool/109349
...
Freed by task:
kvfree
ipc_msg_send_request [ksmbd]
ksmbd_rpc_open -> ksmbd_session_rpc_open [ksmbd]

Fix by:
- Taking ipc_msg_table_lock in ipc_msg_send_request() while validating
entry->response, freeing it when invalid, and removing the entry from
ipc_msg_table.
- Returning the final entry->response pointer to the caller only after
the hash entry is removed under the lock.
- Returning NULL in the error path, preserving the original API
semantics.

This makes all accesses to entry->response consistent with
handle_response(), which already updates and fills the response buffer
under ipc_msg_table_lock, and closes the race that allowed the UAF.

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4476-1 linux-6.1 security update
Debian DSA Debian DSA DSA-6127-1 linux security update
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sun, 11 Jan 2026 16:45:00 +0000


Wed, 17 Dec 2025 12:15:00 +0000


Tue, 16 Dec 2025 15:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ksmbd: ipc: fix use-after-free in ipc_msg_send_request ipc_msg_send_request() waits for a generic netlink reply using an ipc_msg_table_entry on the stack. The generic netlink handler (handle_generic_event()/handle_response()) fills entry->response under ipc_msg_table_lock, but ipc_msg_send_request() used to validate and free entry->response without holding the same lock. Under high concurrency this allows a race where handle_response() is copying data into entry->response while ipc_msg_send_request() has just freed it, leading to a slab-use-after-free reported by KASAN in handle_generic_event(): BUG: KASAN: slab-use-after-free in handle_generic_event+0x3c4/0x5f0 [ksmbd] Write of size 12 at addr ffff888198ee6e20 by task pool/109349 ... Freed by task: kvfree ipc_msg_send_request [ksmbd] ksmbd_rpc_open -> ksmbd_session_rpc_open [ksmbd] Fix by: - Taking ipc_msg_table_lock in ipc_msg_send_request() while validating entry->response, freeing it when invalid, and removing the entry from ipc_msg_table. - Returning the final entry->response pointer to the caller only after the hash entry is removed under the lock. - Returning NULL in the error path, preserving the original API semantics. This makes all accesses to entry->response consistent with handle_response(), which already updates and fills the response buffer under ipc_msg_table_lock, and closes the race that allowed the UAF.
Title ksmbd: ipc: fix use-after-free in ipc_msg_send_request
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-02-09T08:31:22.495Z

Reserved: 2025-12-16T13:41:40.267Z

Link: CVE-2025-68263

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-16T15:15:55.813

Modified: 2026-01-11T17:15:54.443

Link: CVE-2025-68263

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-12-16T00:00:00Z

Links: CVE-2025-68263 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.