From: Shuangpeng Bai Date: Mon, 29 Jun 2026 17:14:22 +0000 (-0400) Subject: libceph: refresh auth->authorizer_buf{,_len} after authorizer update X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=937d61f86d377a3aa578adae7a3dfcecdddf9d89;p=thirdparty%2Fkernel%2Flinux.git libceph: refresh auth->authorizer_buf{,_len} after authorizer update ceph_x_create_authorizer() caches au->buf->vec.iov_base and au->buf->vec.iov_len in struct ceph_auth_handshake. These cached values are then used by the messenger connect code when sending the authorizer. ceph_x_update_authorizer() can rebuild the authorizer when a newer service ticket is available. If the rebuilt authorizer no longer fits in the existing buffer, ceph_x_build_authorizer() drops its reference to au->buf and allocates a new one. If this is the final reference, ceph_buffer_put() frees the old ceph_buffer and its vec.iov_base, but auth->authorizer_buf 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 _copy_from_iter() while tcp_sendmsg() copies the authorizer. Refresh auth->authorizer_buf and auth->authorizer_buf_len after a successful authorizer rebuild so the messenger sends the current buffer. Cc: stable@vger.kernel.org Fixes: 0bed9b5c523d ("libceph: add update_authorizer auth method") Closes: https://lore.kernel.org/all/E378850E-106C-427B-A241-970EB2D054D7@gmail.com/ Signed-off-by: Shuangpeng Bai Reviewed-by: Alex Markuze Signed-off-by: Ilya Dryomov --- diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c index 9e64e82d0b63..50a79e8aa656 100644 --- a/net/ceph/auth_x.c +++ b/net/ceph/auth_x.c @@ -849,9 +849,16 @@ static int ceph_x_update_authorizer( au = (struct ceph_x_authorizer *)auth->authorizer; if (au->secret_id < th->secret_id) { + int ret; + dout("ceph_x_update_authorizer service %u secret %llu < %llu\n", au->service, au->secret_id, th->secret_id); - return ceph_x_build_authorizer(ac, th, au); + ret = ceph_x_build_authorizer(ac, th, au); + if (ret) + return ret; + + auth->authorizer_buf = au->buf->vec.iov_base; + auth->authorizer_buf_len = au->buf->vec.iov_len; } return 0; }