From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 503b934a752f7e789a5f33217520e0a79f3096ac ]
Expanding the READ_PLUS extents can cause the read buffer to overflow. If it does, then don't error, but just exit early.
Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/nfs42xdr.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-)
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c index 8432bd6b95f08..c078f88552695 100644 --- a/fs/nfs/nfs42xdr.c +++ b/fs/nfs/nfs42xdr.c @@ -1019,29 +1019,24 @@ static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *re return decode_op_hdr(xdr, OP_DEALLOCATE); }
-static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *res, - uint32_t *eof) +static int decode_read_plus_data(struct xdr_stream *xdr, + struct nfs_pgio_res *res) { uint32_t count, recvd; uint64_t offset; __be32 *p;
p = xdr_inline_decode(xdr, 8 + 4); - if (unlikely(!p)) - return -EIO; + if (!p) + return 1;
p = xdr_decode_hyper(p, &offset); count = be32_to_cpup(p); recvd = xdr_align_data(xdr, res->count, count); res->count += recvd;
- if (count > recvd) { - dprintk("NFS: server cheating in read reply: " - "count %u > recvd %u\n", count, recvd); - *eof = 0; + if (count > recvd) return 1; - } - return 0; }
@@ -1052,18 +1047,16 @@ static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *re __be32 *p;
p = xdr_inline_decode(xdr, 8 + 8); - if (unlikely(!p)) - return -EIO; + if (!p) + return 1;
p = xdr_decode_hyper(p, &offset); p = xdr_decode_hyper(p, &length); recvd = xdr_expand_hole(xdr, res->count, length); res->count += recvd;
- if (recvd < length) { - *eof = 0; + if (recvd < length) return 1; - } return 0; }
@@ -1088,12 +1081,12 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
for (i = 0; i < segments; i++) { p = xdr_inline_decode(xdr, 4); - if (unlikely(!p)) - return -EIO; + if (!p) + goto early_out;
type = be32_to_cpup(p++); if (type == NFS4_CONTENT_DATA) - status = decode_read_plus_data(xdr, res, &eof); + status = decode_read_plus_data(xdr, res); else if (type == NFS4_CONTENT_HOLE) status = decode_read_plus_hole(xdr, res, &eof); else @@ -1102,12 +1095,17 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res) if (status < 0) return status; if (status > 0) - break; + goto early_out; }
out: res->eof = eof; return 0; +early_out: + if (unlikely(!i)) + return -EIO; + res->eof = 0; + return 0; }
static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)