CVE-2026-64139: ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow

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

ksmbd: fix SID memory leak in setposixaclentriesdacl() on overflow

Commit 299f962c0b02 ("ksmbd: use checkaddoverflow() to prevent u16 DACL size overflow") added checkaddoverflow() guards that break out of the ACE-building loops in setposixaclentriesdacl() when the accumulated DACL size would wrap past 65535.

However, each iteration allocates a struct smbsid via kmallocobj() at the top of the loop and relies on the kfree(sid) call at the end of the loop body (the 'passsamesid' label in the first loop, and the explicit kfree at the tail of the second loop) to release it. The newly introduced 'break' statements bypass those kfree() calls, leaking the sid buffer every time an overflow is detected.

A malicious or malformed file with enough POSIX ACL entries to trip the overflow check will leak one or more struct smbsid allocations on every request that touches the file's DACL, providing a trivial kernel memory exhaustion vector.

Free sid before breaking out of the loops to plug the leak.