From dc2f3db587e548df5fd55a8b420e18ac8c11cb8e Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 20 May 2014 15:03:49 +0200 Subject: [PATCH] IB/srp: Fix a sporadic crash triggered by cable pulling commit 024ca90151f5e4296d30f72c13ff9a075e23c9ec upstream. Avoid that the loops that iterate over the request ring can encounter a pointer to a SCSI command in req->scmnd that is no longer associated with that request. If the function srp_unmap_data() is invoked twice for a SCSI command that is not in flight then that would cause ib_fmr_pool_unmap() to be invoked with an invalid pointer as argument, resulting in a kernel oops. Reported-by: Sagi Grimberg Reference: http://thread.gmane.org/gmane.linux.drivers.rdma/19068/focus=19069 Signed-off-by: Bart Van Assche Reviewed-by: Sagi Grimberg Signed-off-by: Roland Dreier Signed-off-by: Ben Hutchings --- drivers/infiniband/ulp/srp/ib_srp.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 4ec049db69350..8770d4449d6f9 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -1353,6 +1353,12 @@ err_unmap: err_iu: srp_put_tx_iu(target, iu, SRP_IU_CMD); + /* + * Avoid that the loops that iterate over the request ring can + * encounter a dangling SCSI command pointer. + */ + req->scmnd = NULL; + spin_lock_irqsave(&target->lock, flags); list_add(&req->list, &target->free_reqs); -- 2.47.3