From 0ba7536d5d47e4ecf2259a80b207158dc4e711eb Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 7 Nov 2005 01:00:26 -0800 Subject: [PATCH] [PATCH] knfsd: Fix some minor sign problems in nfsd/xdr There are a couple of tests which could possibly be confused by extremely large numbers appearing in 'xdr' packets. I think the closest to an exploit you could get would be writing random data from a free page into a file - i.e. leak data out of kernel space. I'm fairly sure they cannot be used for remote compromise. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfsd/nfs3xdr.c | 3 ++- include/linux/nfsd/xdr3.h | 2 +- include/linux/sunrpc/svc.h | 3 ++- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index e0e134d6ba..9147b8524d 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -366,7 +366,8 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, u32 *p, len = args->len = ntohl(*p++); hdr = (void*)p - rqstp->rq_arg.head[0].iov_base; - if (rqstp->rq_arg.len < len + hdr) + if (rqstp->rq_arg.len < hdr || + rqstp->rq_arg.len - hdr < len) return 0; args->vec[0].iov_base = (void*)p; diff --git a/include/linux/nfsd/xdr3.h b/include/linux/nfsd/xdr3.h index 21e18ce7ca..3c2a71b43b 100644 --- a/include/linux/nfsd/xdr3.h +++ b/include/linux/nfsd/xdr3.h @@ -42,7 +42,7 @@ struct nfsd3_writeargs { __u64 offset; __u32 count; int stable; - int len; + __u32 len; struct kvec vec[RPCSVC_MAXPAGES]; int vlen; }; diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 5af8800e0c..e4086ec8b9 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -171,7 +171,8 @@ xdr_argsize_check(struct svc_rqst *rqstp, u32 *p) { char *cp = (char *)p; struct kvec *vec = &rqstp->rq_arg.head[0]; - return cp - (char*)vec->iov_base <= vec->iov_len; + return cp >= (char*)vec->iov_base + && cp <= (char*)vec->iov_base + vec->iov_len; } static inline int -- 2.39.5