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 <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index d8bd97a5..3dfd769 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1616,7 +1616,7 @@ gss_validate(struct rpc_task *task, __be32 *p)
{
struct rpc_cred *cred = task->tk_rqstp->rq_cred;
struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
- __be32 seq;
+ __be32 *seq = NULL;
struct kvec iov;
struct xdr_buf verf_buf;
struct xdr_netobj mic;
@@ -1631,9 +1631,12 @@ gss_validate(struct rpc_task *task, __be32 *p)
goto out_bad;
if (flav != RPC_AUTH_GSS)
goto out_bad;
- seq = htonl(task->tk_rqstp->rq_seqno);
- iov.iov_base = &seq;
- iov.iov_len = sizeof(seq);
+ seq = kmalloc(4, GFP_NOFS);
+ if (!seq)
+ goto out_bad;
+ *seq = htonl(task->tk_rqstp->rq_seqno);
+ iov.iov_base = seq;
+ iov.iov_len = 4;
xdr_buf_from_iov(&iov, &verf_buf);
mic.data = (u8 *)p;
mic.len = len;
@@ -1653,11 +1656,13 @@ gss_validate(struct rpc_task *task, __be32 *p)
gss_put_ctx(ctx);
dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
task->tk_pid, __func__);
+ kfree(seq);
return p + XDR_QUADLEN(len);
out_bad:
gss_put_ctx(ctx);
dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
PTR_ERR(ret));
+ kfree(seq);
return ret;
}
