diff options
| author | Maor Gottlieb <maorg@mellanox.com> | 2017-08-16 18:57:04 +0300 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2017-08-16 12:53:15 -0400 |
| commit | 870201f95fcbd19538aef630393fe9d583eff82e (patch) | |
| tree | 4d465d12776a4ee8f8f7ae1af7f03e3535d499b4 /drivers | |
| parent | 06f8174a97822f6befd28fc2dd315b43b82c700f (diff) | |
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: 036b10635739 ('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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/infiniband/core/uverbs_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index c023e2c81b8f..5e530d2bee44 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -1153,7 +1153,6 @@ static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev, kref_get(&file->ref); mutex_unlock(&uverbs_dev->lists_mutex); - ib_uverbs_event_handler(&file->event_handler, &event); mutex_lock(&file->cleanup_mutex); ucontext = file->ucontext; @@ -1170,6 +1169,7 @@ static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev, * for example due to freeing the resources * (e.g mmput). */ + ib_uverbs_event_handler(&file->event_handler, &event); ib_dev->disassociate_ucontext(ucontext); mutex_lock(&file->cleanup_mutex); ib_uverbs_cleanup_ucontext(file, ucontext, true); |