CVE-2026-90174CVE-2026-90174

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds read in ksmbd_alloc_user() ksmbd_alloc_user() copies resp->hash_sz bytes out of the mountd IPC login response with user->passkey_sz = resp->hash_sz; user->passkey = kmalloc(resp->hash_sz, KSMBD_DEFAULT_GFP); if (user->passkey) memcpy(user->passkey, resp->hash, resp->hash_sz); resp->hash_sz is a __u16 supplied by the response, but resp->hash[] is only KSMBD_REQ_MAX_HASH_SZ bytes. A malformed or malicious login response can set hash_sz well beyond that (up to 65535), so the memcpy() reads past the end of the response object. ipc_validate_msg() does not bound hash_sz, so reject any response whose hash_sz exceeds the on-stack hash[] buffer before allocating and copying. [ 2030.238706] BUG: KASAN: slab-out-of-bounds in ksmbd_alloc_user+0x278/0x680 [ 2030.240549] Read of size 65535 at addr ffff888121bb6680 by task kworker/4:1/18611 [ 2030.242296] [ 2030.242710] CPU: 4 UID: 0 PID: 186