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-rw-r--r--fs/nfsd/nfs3xdr.c12
-rw-r--r--fs/nfsd/nfs4xdr.c8
-rw-r--r--fs/nfsd/nfssvc.c36
-rw-r--r--fs/nfsd/nfsxdr.c10
4 files changed, 54 insertions, 12 deletions
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index e4b2b4322553..ea2138726365 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -358,6 +358,7 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
{
unsigned int len, v, hdr, dlen;
u32 max_blocksize = svc_max_payload(rqstp);
+ struct kvec *head = rqstp->rq_arg.head;
p = decode_fh(p, &args->fh);
if (!p)
@@ -367,6 +368,8 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
args->count = ntohl(*p++);
args->stable = ntohl(*p++);
len = args->len = ntohl(*p++);
+ if ((void *)p > head->iov_base + head->iov_len)
+ return 0;
/*
* The count must equal the amount of data passed.
*/
@@ -377,9 +380,8 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
* Check to make sure that we got the right number of
* bytes.
*/
- hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
- dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
- - hdr;
+ hdr = (void*)p - head->iov_base;
+ dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
/*
* Round the length of the data which was specified up to
* the next multiple of XDR units and then compare that
@@ -396,7 +398,7 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
len = args->len = max_blocksize;
}
rqstp->rq_vec[0].iov_base = (void*)p;
- rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
+ rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
v = 0;
while (len > rqstp->rq_vec[v].iov_len) {
len -= rqstp->rq_vec[v].iov_len;
@@ -471,6 +473,8 @@ nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
/* first copy and check from the first page */
old = (char*)p;
vec = &rqstp->rq_arg.head[0];
+ if ((void *)old > vec->iov_base + vec->iov_len)
+ return 0;
avail = vec->iov_len - (old - (char*)vec->iov_base);
while (len && avail && *old) {
*new++ = *old++;
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index d8297542f8b3..16fcfdd6011c 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4021,8 +4021,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
struct nfsd4_getdeviceinfo *gdev)
{
struct xdr_stream *xdr = &resp->xdr;
- const struct nfsd4_layout_ops *ops =
- nfsd4_layout_ops[gdev->gd_layout_type];
+ const struct nfsd4_layout_ops *ops;
u32 starting_len = xdr->buf->len, needed_len;
__be32 *p;
@@ -4039,6 +4038,7 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
/* If maxcount is 0 then just update notifications */
if (gdev->gd_maxcount != 0) {
+ ops = nfsd4_layout_ops[gdev->gd_layout_type];
nfserr = ops->encode_getdeviceinfo(xdr, gdev);
if (nfserr) {
/*
@@ -4091,8 +4091,7 @@ nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
struct nfsd4_layoutget *lgp)
{
struct xdr_stream *xdr = &resp->xdr;
- const struct nfsd4_layout_ops *ops =
- nfsd4_layout_ops[lgp->lg_layout_type];
+ const struct nfsd4_layout_ops *ops;
__be32 *p;
dprintk("%s: err %d\n", __func__, nfserr);
@@ -4115,6 +4114,7 @@ nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
*p++ = cpu_to_be32(lgp->lg_seg.iomode);
*p++ = cpu_to_be32(lgp->lg_layout_type);
+ ops = nfsd4_layout_ops[lgp->lg_layout_type];
nfserr = ops->encode_layoutget(xdr, lgp);
out:
kfree(lgp->lg_content);
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 9277cc91c21b..c493427e9d69 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -647,6 +647,37 @@ static __be32 map_new_errors(u32 vers, __be32 nfserr)
return nfserr;
}
+/*
+ * A write procedure can have a large argument, and a read procedure can
+ * have a large reply, but no NFSv2 or NFSv3 procedure has argument and
+ * reply that can both be larger than a page. The xdr code has taken
+ * advantage of this assumption to be a sloppy about bounds checking in
+ * some cases. Pending a rewrite of the NFSv2/v3 xdr code to fix that
+ * problem, we enforce these assumptions here:
+ */
+static bool nfs_request_too_big(struct svc_rqst *rqstp,
+ struct svc_procedure *proc)
+{
+ /*
+ * The ACL code has more careful bounds-checking and is not
+ * susceptible to this problem:
+ */
+ if (rqstp->rq_prog != NFS_PROGRAM)
+ return false;
+ /*
+ * Ditto NFSv4 (which can in theory have argument and reply both
+ * more than a page):
+ */
+ if (rqstp->rq_vers >= 4)
+ return false;
+ /* The reply will be small, we're OK: */
+ if (proc->pc_xdrressize > 0 &&
+ proc->pc_xdrressize < XDR_QUADLEN(PAGE_SIZE))
+ return false;
+
+ return rqstp->rq_arg.len > PAGE_SIZE;
+}
+
int
nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
{
@@ -659,6 +690,11 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
rqstp->rq_vers, rqstp->rq_proc);
proc = rqstp->rq_procinfo;
+ if (nfs_request_too_big(rqstp, proc)) {
+ dprintk("nfsd: NFSv%d argument too large\n", rqstp->rq_vers);
+ *statp = rpc_garbage_args;
+ return 1;
+ }
/*
* Give the xdr decoder a chance to change this if it wants
* (necessary in the NFSv4.0 compound case)
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index 79d964aa8079..bf913201a6ad 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -280,6 +280,7 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
struct nfsd_writeargs *args)
{
unsigned int len, hdr, dlen;
+ struct kvec *head = rqstp->rq_arg.head;
int v;
p = decode_fh(p, &args->fh);
@@ -300,9 +301,10 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
* Check to make sure that we got the right number of
* bytes.
*/
- hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
- dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
- - hdr;
+ hdr = (void*)p - head->iov_base;
+ if (hdr > head->iov_len)
+ return 0;
+ dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
/*
* Round the length of the data which was specified up to
@@ -316,7 +318,7 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
return 0;
rqstp->rq_vec[0].iov_base = (void*)p;
- rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
+ rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
v = 0;
while (len > rqstp->rq_vec[v].iov_len) {
len -= rqstp->rq_vec[v].iov_len;
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-30 22:25:48 +0000