From 25fd08eb2be0fcebd5ab7bb8e1d4fe228c6739d0 Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Thu, 21 Feb 2019 18:07:42 +0200 Subject: [PATCH] RDMA/uverbs: Store PR pointer before it is overwritten The IB_MR_REREG_PD command rewrites mr->pd after successful rereg_user_mr(), such change causes to lost usecnt information and produces the following warning: WARNING: CPU: 1 PID: 1771 at drivers/infiniband/core/verbs.c:336 ib_dealloc_pd+0x4e/0x60 [ib_core] CPU: 1 PID: 1771 Comm: rereg_mr Tainted: G W OE 5.0.0-rc7-for-upstream-perf-2019-02-20_14-03-40-34 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:ib_dealloc_pd+0x4e/0x60 [ib_core] RSP: 0018:ffffc90003923dc0 EFLAGS: 00010286 RAX: 00000000ffffffff RBX: ffff88821f7f0400 RCX: ffff888236a40c00 RDX: ffff88821f7f0400 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffff88835f665d80 R09: ffff8882209c90d8 R10: ffff88835ec003e0 R11: 0000000000000000 R12: ffff888221680ba0 R13: ffff888221680b00 R14: 00000000ffffffea R15: ffff88821f53c318 FS: 00007f70db11e740(0000) GS:ffff88835f640000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001dfd030 CR3: 000000029d9d8000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: uverbs_free_pd+0x2d/0x30 [ib_uverbs] destroy_hw_idr_uobject+0x16/0x40 [ib_uverbs] uverbs_destroy_uobject+0x28/0x170 [ib_uverbs] __uverbs_cleanup_ufile+0x6b/0x90 [ib_uverbs] uverbs_destroy_ufile_hw+0x8b/0x110 [ib_uverbs] ib_uverbs_close+0x1f/0x80 [ib_uverbs] __fput+0xb1/0x220 task_work_run+0x7f/0xa0 exit_to_usermode_loop+0x6b/0xb2 do_syscall_64+0xc5/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f70dad00664 Fixes: e278173fd19e ("RDMA/core: Cosmetic change - move member initialization to correct block") Signed-off-by: Leon Romanovsky Reviewed-by: Majd Dibbiny Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/uverbs_cmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 6fcfaca82332..e44ac718f1cd 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -819,6 +819,7 @@ static int ib_uverbs_rereg_mr(struct uverbs_attr_bundle *attrs) } } + old_pd = mr->pd; ret = mr->device->ops.rereg_user_mr(mr, cmd.flags, cmd.start, cmd.length, cmd.hca_va, cmd.access_flags, pd, @@ -827,7 +828,6 @@ static int ib_uverbs_rereg_mr(struct uverbs_attr_bundle *attrs) goto put_uobj_pd; if (cmd.flags & IB_MR_REREG_PD) { - old_pd = mr->pd; atomic_inc(&pd->usecnt); mr->pd = pd; atomic_dec(&old_pd->usecnt); -- 2.45.2