CVE-2025-68263
Critical · 9.8CVSS
9.8
EPSS
0.4%
Published
Dec 16, 2025
CISA due date
—
The record
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.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Linux | Kernel | 0 | 6.12.62 |
| Linux | Kernel | 5.15.0 | 6.1.160 |
| Linux | Kernel | 5.15.0 | 6.12.62 |
| openSUSE:Tumbleweed | kernel-source | 0 | 6.18.2-1.1 |
| openSUSE:Tumbleweed | kernel-source-longterm | 0 | 6.18.16-1.1 |
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