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authorJulian Wiedmann <jwi@linux.ibm.com>2019-06-18 11:25:59 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-21 09:07:15 +0200
commitff5e6f2e7497e93aa5be513634c9de789bd2d3cc (patch)
tree340ba338eb3548c0218cc10e0ae082bb7bf3e106
parenta4db5127609328f80d848d2660e5f6c5c68b25c0 (diff)
s390/qdio: (re-)initialize tiqdio list entries
commit e54e4785cb5cb4896cf4285964aeef2125612fb2 upstream. When tiqdio_remove_input_queues() removes a queue from the tiq_list as part of qdio_shutdown(), it doesn't re-initialize the queue's list entry and the prev/next pointers go stale. If a subsequent qdio_establish() fails while sending the ESTABLISH cmd, it calls qdio_shutdown() again in QDIO_IRQ_STATE_ERR state and tiqdio_remove_input_queues() will attempt to remove the queue entry a second time. This dereferences the stale pointers, and bad things ensue. Fix this by re-initializing the list entry after removing it from the list. For good practice also initialize the list entry when the queue is first allocated, and remove the quirky checks that papered over this omission. Note that prior to commit e521813468f7 ("s390/qdio: fix access to uninitialized qdio_q fields"), these checks were bogus anyway. setup_queues_misc() clears the whole queue struct, and thus needs to re-init the prev/next pointers as well. Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.") Cc: <stable@vger.kernel.org> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/s390/cio/qdio_setup.c2
-rw-r--r--drivers/s390/cio/qdio_thinint.c4
2 files changed, 4 insertions, 2 deletions
diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c
index 35286907c636..d0090c5c88e7 100644
--- a/drivers/s390/cio/qdio_setup.c
+++ b/drivers/s390/cio/qdio_setup.c
@@ -150,6 +150,7 @@ static int __qdio_allocate_qs(struct qdio_q **irq_ptr_qs, int nr_queues)
return -ENOMEM;
}
irq_ptr_qs[i] = q;
+ INIT_LIST_HEAD(&q->entry);
}
return 0;
}
@@ -178,6 +179,7 @@ static void setup_queues_misc(struct qdio_q *q, struct qdio_irq *irq_ptr,
q->mask = 1 << (31 - i);
q->nr = i;
q->handler = handler;
+ INIT_LIST_HEAD(&q->entry);
}
static void setup_storage_lists(struct qdio_q *q, struct qdio_irq *irq_ptr,
diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c
index 30e9fbbff051..1139bbb1ff1f 100644
--- a/drivers/s390/cio/qdio_thinint.c
+++ b/drivers/s390/cio/qdio_thinint.c
@@ -88,14 +88,14 @@ void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
struct qdio_q *q;
q = irq_ptr->input_qs[0];
- /* if establish triggered an error */
- if (!q || !q->entry.prev || !q->entry.next)
+ if (!q)
return;
mutex_lock(&tiq_list_lock);
list_del_rcu(&q->entry);
mutex_unlock(&tiq_list_lock);
synchronize_rcu();
+ INIT_LIST_HEAD(&q->entry);
}
static inline int has_multiple_inq_on_dsci(struct qdio_irq *irq_ptr)