From: Jason Gunthorpe Date: Tue, 13 Feb 2018 10:18:40 +0000 (+0200) Subject: IB/uverbs: Fix unbalanced unlock on error path for rdma_explicit_destroy X-Git-Tag: v4.16-rc3~22^2~14 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=ec6f8401c48a86809237e86878a6fac6b281118f;p=linux.git IB/uverbs: Fix unbalanced unlock on error path for rdma_explicit_destroy If remove_commit fails then the lock is left locked while the uobj still exists. Eventually the kernel will deadlock. lockdep detects this and says: test/4221 is leaving the kernel with locks still held! 1 lock held by test/4221: #0: (&ucontext->cleanup_rwsem){.+.+}, at: [<000000001e5c7523>] rdma_explicit_destroy+0x37/0x120 [ib_uverbs] Fixes: 4da70da23e9b ("IB/core: Explicitly destroy an object while keeping uobject") Signed-off-by: Leon Romanovsky Reviewed-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index cfd257e34e02..d8eead5d106d 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -491,12 +491,13 @@ int rdma_explicit_destroy(struct ib_uobject *uobject) ret = uobject->type->type_class->remove_commit(uobject, RDMA_REMOVE_DESTROY); if (ret) - return ret; + goto out; uobject->type = &null_obj_type; +out: up_read(&ucontext->cleanup_rwsem); - return 0; + return ret; } static void alloc_commit_idr_uobject(struct ib_uobject *uobj)