linux/drivers/infiniband
Maor Gottlieb 870201f95f IB/uverbs: Fix NULL pointer dereference during device removal
As part of ib_uverbs_remove_one which might be triggered upon
reset flow, we trigger IB_EVENT_DEVICE_FATAL event to userspace
application.
If device was removed after uverbs fd was opened but before
ib_uverbs_get_context was called, the event file will be accessed
before it was allocated, result in NULL pointer dereference:

[ 72.325873] BUG: unable to handle kernel NULL pointer dereference at (null)
...
[ 72.325984] IP: _raw_spin_lock_irqsave+0x22/0x40
[ 72.327123] Call Trace:
[ 72.327168] ib_uverbs_async_handler.isra.8+0x2e/0x160 [ib_uverbs]
[ 72.327216] ? synchronize_srcu_expedited+0x27/0x30
[ 72.327269] ib_uverbs_remove_one+0x120/0x2c0 [ib_uverbs]
[ 72.327330] ib_unregister_device+0xd0/0x180 [ib_core]
[ 72.327373] mlx5_ib_remove+0x74/0x140 [mlx5_ib]
[ 72.327422] mlx5_remove_device+0xfb/0x110 [mlx5_core]
[ 72.327466] mlx5_unregister_interface+0x3c/0xa0 [mlx5_core]
[ 72.327509] mlx5_ib_cleanup+0x10/0x962 [mlx5_ib]
[ 72.327546] SyS_delete_module+0x155/0x230
[ 72.328472] ? exit_to_usermode_loop+0x70/0xa6
[ 72.329370] do_syscall_64+0x54/0xc0
[ 72.330262] entry_SYSCALL64_slow_path+0x25/0x25

Fix it by checking that user context was allocated before
trigger the event.

Fixes: 036b106357 ('IB/uverbs: Enable device removal when there are active user space applications')
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-08-16 12:53:15 -04:00
..
core IB/uverbs: Fix NULL pointer dereference during device removal 2017-08-16 12:53:15 -04:00
hw iw_cxgb4: fix misuse of integer variable 2017-08-16 11:43:21 -04:00
sw rxe: fix broken receive queue draining 2017-07-20 11:20:50 -04:00
ulp IB/ipoib: Notify on modify QP failure only when relevant 2017-07-23 10:52:00 +03:00
Kconfig IB/opa-vnic: Virtual Network Interface Controller (VNIC) netdev 2017-04-20 12:01:38 -04:00
Makefile IB/rdmavt: Create module framework and handle driver registration 2016-03-10 20:37:04 -05:00