* [PATCH AUTOSEL 4.14 02/16] rpc: fix NULL dereference on kmalloc failure
[not found] <20210325112751.1928421-1-sashal@kernel.org>
@ 2021-03-25 11:27 ` Sasha Levin
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From: Sasha Levin @ 2021-03-25 11:27 UTC (permalink / raw)
To: linux-kernel, stable
Cc: J. Bruce Fields, Chuck Lever, Sasha Levin, linux-nfs, netdev
From: "J. Bruce Fields" <bfields@redhat.com>
[ Upstream commit 0ddc942394013f08992fc379ca04cffacbbe3dae ]
I think this is unlikely but possible:
svc_authenticate sets rq_authop and calls svcauth_gss_accept. The
kmalloc(sizeof(*svcdata), GFP_KERNEL) fails, leaving rq_auth_data NULL,
and returning SVC_DENIED.
This causes svc_process_common to go to err_bad_auth, and eventually
call svc_authorise. That calls ->release == svcauth_gss_release, which
tries to dereference rq_auth_data.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Link: https://lore.kernel.org/linux-nfs/3F1B347F-B809-478F-A1E9-0BE98E22B0F0@oracle.com/T/#t
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sunrpc/auth_gss/svcauth_gss.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 03043d5221e9..27dfd85830d8 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1713,11 +1713,14 @@ static int
svcauth_gss_release(struct svc_rqst *rqstp)
{
struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
- struct rpc_gss_wire_cred *gc = &gsd->clcred;
+ struct rpc_gss_wire_cred *gc;
struct xdr_buf *resbuf = &rqstp->rq_res;
int stat = -EINVAL;
struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
+ if (!gsd)
+ goto out;
+ gc = &gsd->clcred;
if (gc->gc_proc != RPC_GSS_PROC_DATA)
goto out;
/* Release can be called twice, but we only wrap once. */
@@ -1758,10 +1761,10 @@ svcauth_gss_release(struct svc_rqst *rqstp)
if (rqstp->rq_cred.cr_group_info)
put_group_info(rqstp->rq_cred.cr_group_info);
rqstp->rq_cred.cr_group_info = NULL;
- if (gsd->rsci)
+ if (gsd && gsd->rsci) {
cache_put(&gsd->rsci->h, sn->rsc_cache);
- gsd->rsci = NULL;
-
+ gsd->rsci = NULL;
+ }
return stat;
}
--
2.30.1
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2021-03-25 11:27 ` [PATCH AUTOSEL 4.14 02/16] rpc: fix NULL dereference on kmalloc failure Sasha Levin
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