diff options
authorTomáš Trnka <ttrnka@mail.muni.cz>2016-05-20 16:41:10 +0200
committerSasha Levin <sasha.levin@oracle.com>2016-06-06 19:11:11 -0400
commitb36205bd6c2cb9a742c187a8dde544d2141e0822 (patch)
parent4433e3758946d2e38933765f41716bfc6c1cc3ac (diff)
sunrpc: fix stripping of padded MIC tokens
[ Upstream commit c0cb8bf3a8e4bd82e640862cdd8891400405cb89 ] The length of the GSS MIC token need not be a multiple of four bytes. It is then padded by XDR to a multiple of 4 B, but unwrap_integ_data() would previously only trim mic.len + 4 B. The remaining up to three bytes would then trigger a check in nfs4svc_decode_compoundargs(), leading to a "garbage args" error and mount failure: nfs4svc_decode_compoundargs: compound not properly padded! nfsd: failed to decode arguments! This would prevent older clients using the pre-RFC 4121 MIC format (37-byte MIC including a 9-byte OID) from mounting exports from v3.9+ servers using krb5i. The trimming was introduced by commit 4c190e2f913f ("sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer"). Fixes: 4c190e2f913f "unrpc: trim off trailing checksum..." Signed-off-by: Tomáš Trnka <ttrnka@mail.muni.cz> Cc: stable@vger.kernel.org Acked-by: Jeff Layton <jlayton@poochiereds.net> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
1 files changed, 2 insertions, 2 deletions
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index c548ab213f76..d08f75972c57 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -855,8 +855,8 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct g
goto out;
if (svc_getnl(&buf->head[0]) != seq)
goto out;
- /* trim off the mic at the end before returning */
- xdr_buf_trim(buf, mic.len + 4);
+ /* trim off the mic and padding at the end before returning */
+ xdr_buf_trim(buf, round_up_to_quad(mic.len) + 4);
stat = 0;