From 2876a34466ce382a76b9ffb34757bb48928ac743 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfields@redhat.com>
Date: Tue, 18 Oct 2016 16:30:09 -0400
Subject: sunrpc: don't pass on-stack memory to sg_set_buf
As of ac4e97abce9b "scatterlist: sg_set_buf() argument must be in linear
mapping", sg_set_buf hits a BUG when make_checksum_v2->xdr_process_buf,
among other callers, passes it memory on the stack.
We only need a scatterlist to pass this to the crypto code, and it seems
like overkill to require kmalloc'd memory just to encrypt a few bytes,
but for now this seems the best fix.
Many of these callers are in the NFS write paths, so we allocate with
GFP_NOFS. It might be possible to do without allocations here entirely,
but that would probably be a bigger project.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
net/sunrpc/auth_gss/svcauth_gss.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
(limited to 'net/sunrpc/auth_gss/svcauth_gss.c')
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index d67f7e1bc82d..45662d7f0943 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -718,30 +718,37 @@ gss_write_null_verf(struct svc_rqst *rqstp)
static int
gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
{
- __be32 xdr_seq;
+ __be32 *xdr_seq;
u32 maj_stat;
struct xdr_buf verf_data;
struct xdr_netobj mic;
__be32 *p;
struct kvec iov;
+ int err = -1;
svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
- xdr_seq = htonl(seq);
+ xdr_seq = kmalloc(4, GFP_KERNEL);
+ if (!xdr_seq)
+ return -1;
+ *xdr_seq = htonl(seq);
- iov.iov_base = &xdr_seq;
- iov.iov_len = sizeof(xdr_seq);
+ iov.iov_base = xdr_seq;
+ iov.iov_len = 4;
xdr_buf_from_iov(&iov, &verf_data);
p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
mic.data = (u8 *)(p + 1);
maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
if (maj_stat != GSS_S_COMPLETE)
- return -1;
+ goto out;
*p++ = htonl(mic.len);
memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
p += XDR_QUADLEN(mic.len);
if (!xdr_ressize_check(rqstp, p))
- return -1;
- return 0;
+ goto out;
+ err = 0;
+out:
+ kfree(xdr_seq);
+ return err;
}
struct gss_domain {
--
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