This is a note to let you know that I've just added the patch titled NLM: Fix svcxdr_encode_owner() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nlm-fix-svcxdr_encode_owner.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit eb46482aa9562c2681974f9c08fb460e6e5e6fe0 Author: Chuck Lever <chuck.lever@xxxxxxxxxx> Date: Thu Sep 16 17:24:54 2021 -0400 NLM: Fix svcxdr_encode_owner() [ Upstream commit 89c485c7a3ecbc2ebd568f9c9c2edf3a8cf7485b ] Dai Ngo reports that, since the XDR overhaul, the NLM server crashes when the TEST procedure wants to return NLM_DENIED. There is a bug in svcxdr_encode_owner() that none of our standard test cases found. Replace the open-coded function with a call to an appropriate pre-fabricated XDR helper. Reported-by: Dai Ngo <Dai.Ngo@xxxxxxxxxx> Fixes: a6a63ca5652e ("lockd: Common NLM XDR helpers") Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/lockd/svcxdr.h b/fs/lockd/svcxdr.h index c69a0bb76c940..4f1a451da5ba2 100644 --- a/fs/lockd/svcxdr.h +++ b/fs/lockd/svcxdr.h @@ -134,18 +134,9 @@ svcxdr_decode_owner(struct xdr_stream *xdr, struct xdr_netobj *obj) static inline bool svcxdr_encode_owner(struct xdr_stream *xdr, const struct xdr_netobj *obj) { - unsigned int quadlen = XDR_QUADLEN(obj->len); - __be32 *p; - - if (xdr_stream_encode_u32(xdr, obj->len) < 0) - return false; - p = xdr_reserve_space(xdr, obj->len); - if (!p) + if (obj->len > XDR_MAX_NETOBJ) return false; - p[quadlen - 1] = 0; /* XDR pad */ - memcpy(p, obj->data, obj->len); - - return true; + return xdr_stream_encode_opaque(xdr, obj->data, obj->len) > 0; } #endif /* _LOCKD_SVCXDR_H_ */