CVE-2026-68156

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

libceph: refresh auth->authorizerbuf{,len} after authorizer update

cephxcreateauthorizer() caches au->buf->vec.iovbase and

au->buf->vec.iovlen in struct cephauth_handshake.  These

cached values are then used by the messenger connect code when

sending the authorizer.

cephxupdate_authorizer() can rebuild the authorizer when a newer

service ticket is available.  If the rebuilt authorizer no longer

fits in the existing buffer, cephxbuild_authorizer() drops its

reference to au->buf and allocates a new one.  If this is the final

reference, cephbufferput() frees the old ceph_buffer and its

vec.iovbase, but auth->authorizerbuf still points at that freed

memory.

A subsequent msgr1 reconnect can therefore queue the stale pointer

and trigger a KASAN slab-use-after-free in copyfrom_iter() while

tcp_sendmsg() copies the authorizer.

Refresh auth->authorizerbuf and auth->authorizerbuf_len after a

successful authorizer rebuild so the messenger sends the current

buffer.