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authorEddie Wai <eddie.wai@broadcom.com>2011-12-06 22:41:21 -0800
committerJames Bottomley <JBottomley@Parallels.com>2011-12-14 17:05:23 +0400
commita878185c3b93e692ace0d1628a47f3d75504ab4f (patch)
treec061bbc691ada3711e64331b911b0776b8b22ad4 /drivers/scsi/bnx2i
parentff1d0319ac6a5fd859884b30c0a3cb6733b8fb2d (diff)
downloadblackbird-op-linux-a878185c3b93e692ace0d1628a47f3d75504ab4f.tar.gz
blackbird-op-linux-a878185c3b93e692ace0d1628a47f3d75504ab4f.zip
[SCSI] bnx2i: Fixed kernel panic caused by unprotected task->sc->request deref
During session recovery, the conn_stop call will trigger a flush to all outstanding SCSI cmds in the xmit queue. This will set all outstanding task->sc to NULL prior to the session_teardown call which frees the task memory. In the bnx2i SCSI response processing path, only the task was being checked for NULL under the session lock before the task->sc->request dereferencing. If there are outstanding SCSI cmd responses pending for process, the following kernel panic can be exposed where task->sc was found to be NULL. Call Trace: [ 69.720205] [<ffffffffa040d0d0>] bnx2i_process_new_cqes+0x290/0x3c0 [bnx2i] [ 69.804289] [<ffffffffa040d233>] bnx2i_fastpath_notification+0x33/0xa0 [bnx2 i] [ 69.891490] [<ffffffffa040d37b>] bnx2i_indicate_kcqe+0xdb/0x330 [bnx2i] [ 69.971427] [<ffffffffa03eac5e>] service_kcqes+0x16e/0x1d0 [cnic] [ 70.045132] [<ffffffffa03eacea>] cnic_service_bnx2x_kcq+0x2a/0x50 [cnic] [ 70.126105] [<ffffffffa03ead53>] cnic_service_bnx2x_bh+0x43/0x140 [cnic] [ 70.207081] [<ffffffff81060676>] tasklet_action+0x66/0x110 [ 70.273521] [<ffffffff8106025f>] __do_softirq+0xef/0x220 [ 70.337887] [<ffffffff81447ebc>] call_softirq+0x1c/0x30 This patch adds the !task->sc check and also protects the sc dereferencing under the session lock. Signed-off-by: Eddie Wai <eddie.wai@broadcom.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/bnx2i')
-rw-r--r--drivers/scsi/bnx2i/bnx2i_hwi.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/scsi/bnx2i/bnx2i_hwi.c b/drivers/scsi/bnx2i/bnx2i_hwi.c
index dba72a4e6a1c..1ad0b8225560 100644
--- a/drivers/scsi/bnx2i/bnx2i_hwi.c
+++ b/drivers/scsi/bnx2i/bnx2i_hwi.c
@@ -1906,18 +1906,19 @@ static int bnx2i_queue_scsi_cmd_resp(struct iscsi_session *session,
spin_lock(&session->lock);
task = iscsi_itt_to_task(bnx2i_conn->cls_conn->dd_data,
cqe->itt & ISCSI_CMD_RESPONSE_INDEX);
- if (!task) {
+ if (!task || !task->sc) {
spin_unlock(&session->lock);
return -EINVAL;
}
sc = task->sc;
- spin_unlock(&session->lock);
if (!blk_rq_cpu_valid(sc->request))
cpu = smp_processor_id();
else
cpu = sc->request->cpu;
+ spin_unlock(&session->lock);
+
p = &per_cpu(bnx2i_percpu, cpu);
spin_lock(&p->p_work_lock);
if (unlikely(!p->iothread)) {
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