[PATCH 3.12 050/133] staging/lustre/ptlrpc: Fix a crash when dereferencing NULL pointer

Greg Kroah-Hartman
2014-02-04T22:21:17Z

From: Amir Shehata <amir.shehata@intel.com>

commit 3c92a0bf4d72737035a16c4fe357ccd439c9b7d2 upstream.

When a system runs out of memory and the function
ptlrpc_register_bulk() is called from ptl_send_rpc() the call to
LNetMEAttach() fails due to failure to allocate memory. This forces
the code into an error path, which most probably previously went
untested. The error path:
if (rc != 0) {
CERROR("%s: LNetMEAttach failed x"LPU64"/%d: rc = %dn",
desc->bd_export->exp_obd->obd_name, xid,
posted_md, rc);
break;
}
This print assumes that desc->bd_export is not NULL. However, it is.
In fact it is expected to be NULL. desc->bd_import is the correct
structure to access in this case.

Lustre-change: http://review.whamcloud.com/7121
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3585
Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/lustre/lustre/ptlrpc/niobuf.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/staging/lustre/lustre/ptlrpc/niobuf.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/niobuf.c
@@ -179,7 +179,7 @@ int ptlrpc_register_bulk(struct ptlrpc_r
LNET_UNLINK, LNET_INS_AFTER, &me_h);
if (rc != 0) {
CERROR("%s: LNetMEAttach failed x"LPU64"/%d: rc = %d\n",
- desc->bd_export->exp_obd->obd_name, xid,
+ desc->bd_import->imp_obd->obd_name, xid,
posted_md, rc);
break;
}
@@ -189,7 +189,7 @@ int ptlrpc_register_bulk(struct ptlrpc_r
&desc->bd_mds[posted_md]);
if (rc != 0) {
CERROR("%s: LNetMDAttach failed x"LPU64"/%d: rc = %d\n",
- desc->bd_export->exp_obd->obd_name, xid,
+ desc->bd_import->imp_obd->obd_name, xid,
posted_md, rc);
rc2 = LNetMEUnlink(me_h);
LASSERT(rc2 == 0);
@@ -219,7 +219,7 @@ int ptlrpc_register_bulk(struct ptlrpc_r
/* Holler if peer manages to touch buffers before he knows the xid */
if (desc->bd_md_count != total_md)
CWARN("%s: Peer %s touched %d buffers while I registered\n",
- desc->bd_export->exp_obd->obd_name, libcfs_id2str(peer),
+ desc->bd_import->imp_obd->obd_name, libcfs_id2str(peer),
total_md - desc->bd_md_count);
spin_unlock(&desc->bd_lock);