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authorChuck Lever <chuck.lever@oracle.com>2020-10-31 17:44:25 +0100
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2020-11-12 16:41:26 +0100
commit6c2190b3fcbc92cb79e39cc7e7531656b341e463 (patch)
tree657781a7bb0f2022ba09cac01cbc6b45990f127c /fs/nfs
parentNFSv4.2: fix failure to unregister shrinker (diff)
downloadlinux-6c2190b3fcbc92cb79e39cc7e7531656b341e463.tar.xz
linux-6c2190b3fcbc92cb79e39cc7e7531656b341e463.zip
NFS: Fix listxattr receive buffer size
Certain NFSv4.2/RDMA tests fail with v5.9-rc1. rpcrdma_convert_kvec() runs off the end of the rl_segments array because rq_rcv_buf.tail[0].iov_len holds a very large positive value. The resultant kernel memory corruption is enough to crash the client system. Callers of rpc_prepare_reply_pages() must reserve an extra XDR_UNIT in the maximum decode size for a possible XDR pad of the contents of the xdr_buf's pages. That guarantees the allocated receive buffer will be large enough to accommodate the usual contents plus that XDR pad word. encode_op_hdr() cannot add that extra word. If it does, xdr_inline_pages() underruns the length of the tail iovec. Fixes: 3e1f02123fba ("NFSv4.2: add client side XDR handling for extended attributes") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs42xdr.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 0dc31ad2362e..6e060a88f98c 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -196,7 +196,7 @@
1 + nfs4_xattr_name_maxsz + 1)
#define decode_setxattr_maxsz (op_decode_hdr_maxsz + decode_change_info_maxsz)
#define encode_listxattrs_maxsz (op_encode_hdr_maxsz + 2 + 1)
-#define decode_listxattrs_maxsz (op_decode_hdr_maxsz + 2 + 1 + 1)
+#define decode_listxattrs_maxsz (op_decode_hdr_maxsz + 2 + 1 + 1 + 1)
#define encode_removexattr_maxsz (op_encode_hdr_maxsz + 1 + \
nfs4_xattr_name_maxsz)
#define decode_removexattr_maxsz (op_decode_hdr_maxsz + \
@@ -531,7 +531,7 @@ static void encode_listxattrs(struct xdr_stream *xdr,
{
__be32 *p;
- encode_op_hdr(xdr, OP_LISTXATTRS, decode_listxattrs_maxsz + 1, hdr);
+ encode_op_hdr(xdr, OP_LISTXATTRS, decode_listxattrs_maxsz, hdr);
p = reserve_space(xdr, 12);
if (unlikely(!p))