From 3c4b1419c33c2417836a63f8126834ee36968321 Mon Sep 17 00:00:00 2001 From: Selvin Xavier Date: Wed, 21 Nov 2018 00:05:00 -0800 Subject: RDMA/bnxt_re: Fix system hang when registration with L2 driver fails Driver doesn't release rtnl lock if registration with L2 driver (bnxt_re_register_netdev) fais and this causes hang while requesting for the next lock. [ 371.635416] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 371.635417] kworker/u48:1 D 0 634 2 0x80000000 [ 371.635423] Workqueue: bnxt_re bnxt_re_task [bnxt_re] [ 371.635424] Call Trace: [ 371.635426] ? __schedule+0x36b/0xbd0 [ 371.635429] schedule+0x39/0x90 [ 371.635430] schedule_preempt_disabled+0x11/0x20 [ 371.635431] __mutex_lock+0x45b/0x9c0 [ 371.635433] ? __mutex_lock+0x16d/0x9c0 [ 371.635435] ? bnxt_re_ib_reg+0x2b/0xb30 [bnxt_re] [ 371.635438] ? wake_up_klogd+0x37/0x40 [ 371.635442] bnxt_re_ib_reg+0x2b/0xb30 [bnxt_re] [ 371.635447] bnxt_re_task+0xfd/0x180 [bnxt_re] [ 371.635449] process_one_work+0x216/0x5b0 [ 371.635450] ? process_one_work+0x189/0x5b0 [ 371.635453] worker_thread+0x4e/0x3d0 [ 371.635455] kthread+0x10e/0x140 [ 371.635456] ? process_one_work+0x5b0/0x5b0 [ 371.635458] ? kthread_stop+0x220/0x220 [ 371.635460] ret_from_fork+0x3a/0x50 [ 371.635477] INFO: task NetworkManager:1228 blocked for more than 120 seconds. [ 371.635478] Tainted: G B OE 4.20.0-rc1+ #42 [ 371.635479] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Release the rtnl_lock correctly in the failure path. Fixes: de5c95d0f518 ("RDMA/bnxt_re: Fix system crash during RDMA resource initialization") Signed-off-by: Selvin Xavier Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/bnxt_re/main.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/infiniband/hw/bnxt_re/main.c') diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c index cf2282654210..bd5ded5809f5 100644 --- a/drivers/infiniband/hw/bnxt_re/main.c +++ b/drivers/infiniband/hw/bnxt_re/main.c @@ -1268,6 +1268,7 @@ static int bnxt_re_ib_reg(struct bnxt_re_dev *rdev) /* Registered a new RoCE device instance to netdev */ rc = bnxt_re_register_netdev(rdev); if (rc) { + rtnl_unlock(); pr_err("Failed to register with netedev: %#x\n", rc); return -EINVAL; } -- cgit From a6c66d6a08b88cc10aca9d3f65cfae31e7652a99 Mon Sep 17 00:00:00 2001 From: Selvin Xavier Date: Wed, 21 Nov 2018 00:05:01 -0800 Subject: RDMA/bnxt_re: Avoid accessing the device structure after it is freed When bnxt_re_ib_reg returns failure, the device structure gets freed. Driver tries to access the device pointer after it is freed. [ 4871.034744] Failed to register with netedev: 0xffffffa1 [ 4871.034765] infiniband (null): Failed to register with IB: 0xffffffea [ 4871.046430] ================================================================== [ 4871.046437] BUG: KASAN: use-after-free in bnxt_re_task+0x63/0x180 [bnxt_re] [ 4871.046439] Write of size 4 at addr ffff880fa8406f48 by task kworker/u48:2/17813 [ 4871.046443] CPU: 20 PID: 17813 Comm: kworker/u48:2 Kdump: loaded Tainted: G B OE 4.20.0-rc1+ #42 [ 4871.046444] Hardware name: Dell Inc. PowerEdge R730/0599V5, BIOS 1.0.4 08/28/2014 [ 4871.046447] Workqueue: bnxt_re bnxt_re_task [bnxt_re] [ 4871.046449] Call Trace: [ 4871.046454] dump_stack+0x91/0xeb [ 4871.046458] print_address_description+0x6a/0x2a0 [ 4871.046461] kasan_report+0x176/0x2d0 [ 4871.046463] ? bnxt_re_task+0x63/0x180 [bnxt_re] [ 4871.046466] bnxt_re_task+0x63/0x180 [bnxt_re] [ 4871.046470] process_one_work+0x216/0x5b0 [ 4871.046471] ? process_one_work+0x189/0x5b0 [ 4871.046475] worker_thread+0x4e/0x3d0 [ 4871.046479] kthread+0x10e/0x140 [ 4871.046480] ? process_one_work+0x5b0/0x5b0 [ 4871.046482] ? kthread_stop+0x220/0x220 [ 4871.046486] ret_from_fork+0x3a/0x50 [ 4871.046492] The buggy address belongs to the page: [ 4871.046494] page:ffffea003ea10180 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 4871.046495] flags: 0x57ffffc0000000() [ 4871.046498] raw: 0057ffffc0000000 0000000000000000 ffffea003ea10188 0000000000000000 [ 4871.046500] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 4871.046501] page dumped because: kasan: bad access detected Avoid accessing the device structure once it is freed. Fixes: 497158aa5f52 ("RDMA/bnxt_re: Fix the ib_reg failure cleanup") Signed-off-by: Selvin Xavier Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/bnxt_re/main.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/infiniband/hw/bnxt_re/main.c') diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c index bd5ded5809f5..77f095e5fbe3 100644 --- a/drivers/infiniband/hw/bnxt_re/main.c +++ b/drivers/infiniband/hw/bnxt_re/main.c @@ -1467,6 +1467,7 @@ static void bnxt_re_task(struct work_struct *work) "Failed to register with IB: %#x", rc); bnxt_re_remove_one(rdev); bnxt_re_dev_unreg(rdev); + goto exit; } break; case NETDEV_UP: @@ -1490,6 +1491,7 @@ static void bnxt_re_task(struct work_struct *work) } smp_mb__before_atomic(); atomic_dec(&rdev->sched_count); +exit: kfree(re_work); } -- cgit