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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 09:00:43 +0200
commitc26226c589f98630f9af4f904b4619336944651f (patch)
tree463761178277ebf96186cf15e924468a7fda9d52
parent3bbbf5bbe7bf7511cc6f96c223acab631f6f1f82 (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 99d7d2566a3a..d4101cecdc8d 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 28d59ac2204c..07264bd9ad0b 100644
--- a/drivers/s390/cio/qdio_thinint.c
+++ b/drivers/s390/cio/qdio_thinint.c
@@ -87,14 +87,14 @@ 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)