From 27b0fcae8f535fb882b1876227a935dcfdf576aa Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Sat, 20 Dec 2025 10:41:09 -0500 Subject: xdrgen: Initialize data pointer for zero-length items The xdrgen decoders for strings and opaque data had an optimization that skipped calling xdr_inline_decode() when the item length was zero. This left the data pointer uninitialized, which could lead to unpredictable behavior when callers access it. Remove the zero-length check and always call xdr_inline_decode(). When passed a length of zero, xdr_inline_decode() returns the current buffer position, which is valid and matches the behavior of hand-coded XDR decoders throughout the kernel. Fixes: 4b132aacb076 ("tools: Add xdrgen") Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever --- include/linux/sunrpc/xdrgen/_builtins.h | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) (limited to 'include') diff --git a/include/linux/sunrpc/xdrgen/_builtins.h b/include/linux/sunrpc/xdrgen/_builtins.h index 52ed9a9151c4..a723fb1da9c8 100644 --- a/include/linux/sunrpc/xdrgen/_builtins.h +++ b/include/linux/sunrpc/xdrgen/_builtins.h @@ -248,12 +248,10 @@ xdrgen_decode_string(struct xdr_stream *xdr, string *ptr, u32 maxlen) return false; if (unlikely(maxlen && len > maxlen)) return false; - if (len != 0) { - p = xdr_inline_decode(xdr, len); - if (unlikely(!p)) - return false; - ptr->data = (unsigned char *)p; - } + p = xdr_inline_decode(xdr, len); + if (unlikely(!p)) + return false; + ptr->data = (unsigned char *)p; ptr->len = len; return true; } @@ -279,12 +277,10 @@ xdrgen_decode_opaque(struct xdr_stream *xdr, opaque *ptr, u32 maxlen) return false; if (unlikely(maxlen && len > maxlen)) return false; - if (len != 0) { - p = xdr_inline_decode(xdr, len); - if (unlikely(!p)) - return false; - ptr->data = (u8 *)p; - } + p = xdr_inline_decode(xdr, len); + if (unlikely(!p)) + return false; + ptr->data = (u8 *)p; ptr->len = len; return true; } -- cgit v1.2.3