From e76debd996c6c0296fbdcba275b4f875e07a0eff Mon Sep 17 00:00:00 2001 From: Ming Lin Date: Fri, 1 Jul 2016 12:13:32 -0700 Subject: [PATCH] nvme-fabrics: add-remove ctrl repeat fix Repeatedly adding then removing the same NVMe-over-Fabrics controller over and over again (shown below) can cause a kernel crash (also shown below). This patch fixes that. [nvmf]# ./setup_nvme_connections.sh traddr=192.168.1.100,transport=rdma,trsvcid=4420,nqn=darkside -nqn,hostnqn=evil-wins-nqn,nr_io_queues=16 > /dev/nvme-fabrics traddr=192.168.1.100,transport=rdma,trsvcid=4420,nqn=lightside -nqn,hostnqn=good-wins-nqn > /dev/nvme-fabrics [nvmf]# ./remove_nvme_connections.sh 2 echo 1 > /sys/class/nvme/nvme0/delete_controller echo 1 > /sys/class/nvme/nvme1/delete_controller [nvmf]# ./setup_nvme_connections.sh traddr=192.168.1.100,transport=rdma,trsvcid=4420,nqn=darkside -nqn,hostnqn=evil-wins-nqn,nr_io_queues=16 > /dev/nvme-fabrics Killed [nvmf]# dmesg [ 313.416908] nvme nvme0: creating 16 I/O queues. [ 313.523908] nvme nvme0: new ctrl: NQN "darkside-nqn", addr 192.168.1.100:4420 [ 313.524857] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 313.525262] IP: [] strcmp+0xe/0x30 [ 313.525490] PGD 0 [ 313.525726] Oops: 0000 [#1] SMP [ 313.525900] Modules linked in: nvme_rdma nvme_fabrics nvme_core ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm mlx4_en mlx4_ib ib_core mlx4_core [ 313.527085] CPU: 15 PID: 5856 Comm: setup_nvme_conn Not tainted 4.7.0-rc2+ #2 [ 313.527259] Hardware name: Supermicro X9DRT-F/IBQF/IBFF/X9DRT -F/IBQF/IBFF, BIOS 1.0a 10/09/2012 [ 313.527551] task: ffff88027646cd40 ti: ffff88025b980000 task.ti: ffff88025b980000 [ 313.527879] RIP: 0010:[] [] strcmp+0xe/0x30 [ 313.528232] RSP: 0018:ffff88025b983db0 EFLAGS: 00010206 [ 313.528403] RAX: 0000000000000000 RBX: ffff880471879880 RCX: fffffffffffffff1 [ 313.528594] RDX: 0000000000000000 RSI: ffff880474afa860 RDI: 0000000000000011 [ 313.528778] RBP: ffff88025b983db0 R08: ffff880474afa860 R09: ffff880471879058 [ 313.528956] R10: 000000000000002c R11: ffff88047f415000 R12: ffff880471879800 [ 313.529129] R13: ffff880471879000 R14: ffff880474afa860 R15: fffffffffffffff8 [ 313.529303] FS: 00007f778f510700(0000) GS:ffff88047fbc0000(0000) knlGS:0000000000000000 [ 313.529629] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 313.529817] CR2: 0000000000000010 CR3: 0000000274174000 CR4: 00000000000406e0 [ 313.529989] Stack: [ 313.530154] ffff88025b983e48 ffffffffa0171c74 0000000000000001 0000000000000059 [ 313.530621] ffff880476f32400 ffff88047e8add80 0000010074b33aa0 ffff880471879059 [ 313.531162] ffff88047187904b ffff880471879058 0000000000000000 ffff88047736e000 [ 313.531629] Call Trace: [ 313.531797] [] nvmf_dev_write+0x674/0x840 [nvme_fabrics] [ 313.531974] [] __vfs_write+0x23/0x120 [ 313.532146] [] ? __fd_install+0x1f/0xc0 [ 313.532316] [] ? __alloc_fd+0x3a/0x170 [ 313.532487] [] vfs_write+0xb3/0x1b0 [ 313.532658] [] ? filp_close+0x51/0x70 [ 313.532845] [] SyS_write+0x41/0xa0 [ 313.533016] [] entry_SYSCALL_64_fastpath+0x13/0x8f [ 313.533188] Code: 80 3a 00 75 f7 48 83 c6 01 0f b6 4e ff 48 83 c2 01 84 c9 88 4a ff 75 ed 5d c3 0f 1f 00 55 48 89 e5 eb 04 84 c0 74 18 48 83 c7 01 <0f> b6 47 ff 48 83 c6 01 3a 46 ff 74 eb 19 c0 83 c8 01 5d c3 31 [ 313.536563] RIP [] strcmp+0xe/0x30 [ 313.536815] RSP [ 313.536981] CR2: 0000000000000010 [ 313.537151] ---[ end trace 3d952e590e7bc2d5 ]--- Reported-and-tested-by: Jay Freyensee Signed-off-by: Ming Lin Signed-off-by: Jay Freyensee Signed-off-by: Jens Axboe --- drivers/nvme/host/fabrics.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c index 0a5a4c4684bc..dc996761042f 100644 --- a/drivers/nvme/host/fabrics.c +++ b/drivers/nvme/host/fabrics.c @@ -88,6 +88,10 @@ static void nvmf_host_destroy(struct kref *ref) { struct nvmf_host *host = container_of(ref, struct nvmf_host, ref); + mutex_lock(&nvmf_hosts_mutex); + list_del(&host->list); + mutex_unlock(&nvmf_hosts_mutex); + kfree(host); } -- 2.20.1