From: Dean Luick dean.luick@cornelisnetworks.com
[ Upstream commit 1afac08b39d85437187bb2a92d89a741b1078f55 ]
Commit 13bac861952a ("IB/hfi1: Fix abba locking issue with sc_disable()") incorrectly tries to move a list from one list head to another. The result is a kernel crash.
The crash is triggered when a link goes down and there are waiters for a send to complete. The following signature is seen:
BUG: kernel NULL pointer dereference, address: 0000000000000030 [...] Call Trace: sc_disable+0x1ba/0x240 [hfi1] pio_freeze+0x3d/0x60 [hfi1] handle_freeze+0x27/0x1b0 [hfi1] process_one_work+0x1b0/0x380 ? process_one_work+0x380/0x380 worker_thread+0x30/0x360 ? process_one_work+0x380/0x380 kthread+0xd7/0x100 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30
The fix is to use the correct call to move the list.
Fixes: 13bac861952a ("IB/hfi1: Fix abba locking issue with sc_disable()") Signed-off-by: Dean Luick dean.luick@cornelisnetworks.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@cornelisnetworks.com Link: https://lore.kernel.org/r/166610327042.674422.6146908799669288976.stgit@awfm... Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/hfi1/pio.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c index 1cd8f80f097a..60eb3a64518f 100644 --- a/drivers/infiniband/hw/hfi1/pio.c +++ b/drivers/infiniband/hw/hfi1/pio.c @@ -955,8 +955,7 @@ void sc_disable(struct send_context *sc) spin_unlock(&sc->release_lock);
write_seqlock(&sc->waitlock); - if (!list_empty(&sc->piowait)) - list_move(&sc->piowait, &wake_list); + list_splice_init(&sc->piowait, &wake_list); write_sequnlock(&sc->waitlock); while (!list_empty(&wake_list)) { struct iowait *wait;