# CVE-2025-68263: ksmbd: ipc: fix use-after-free in ipc_msg_send_request

CVE-2025-68263 is fixed in linux on 1 platform, first by DEBIAN-CVE-2025-68263, released December 16, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-68263
- Priority: High
- CVSS: 9.8 (Moderate)
- EPSS: 0.0044
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 16, 2025
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-68263

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.162-1 | [DEBIAN-CVE-2025-68263](https://patchblox.com/security/data/fix/linux/debian-cve-2025-68263.md) | Dec 16, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.12.63-1 | [DEBIAN-CVE-2025-68263](https://patchblox.com/security/data/fix/linux/debian-cve-2025-68263.md) | Dec 16, 2025 |
| Linux | linux Debian 14 | 6.17.12-1 | [DEBIAN-CVE-2025-68263](https://patchblox.com/security/data/fix/linux/debian-cve-2025-68263.md) | Dec 16, 2025 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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