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authorJulian Wiedmann <jwi@linux.ibm.com>2019-06-18 11:25:59 +0200
committerVasily Gorbik <gor@linux.ibm.com>2019-07-02 16:00:27 +0200
commite54e4785cb5cb4896cf4285964aeef2125612fb2 (patch)
tree3a80e8ff1a7c137bd853279a421101a0399d7645 /drivers/s390/cio/qdio_thinint.c
parents390/dasd: Fix a precision vs width bug in dasd_feature_list() (diff)
downloadlinux-dev-e54e4785cb5cb4896cf4285964aeef2125612fb2.tar.xz
linux-dev-e54e4785cb5cb4896cf4285964aeef2125612fb2.zip
s390/qdio: (re-)initialize tiqdio list entries
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>
Diffstat (limited to '')
-rw-r--r--drivers/s390/cio/qdio_thinint.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/s390/cio/qdio_thinint.c b/drivers/s390/cio/qdio_thinint.c
index b84ac7ae8a3e..75e4357c1f9d 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)