The commit mentioned in Fixes line missed a couple of notifications that
were registered before devlink_register() and should be delayed too.

As such, the too early placed WARN_ON() check spotted it.

WARNING: CPU: 1 PID: 6540 at net/core/devlink.c:5158 devlink_nl_region_notify+0x184/0x1e0 net/core/devlink.c:5158
Modules linked in:
CPU: 1 PID: 6540 Comm: syz-executor.0 Not tainted 5.15.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:devlink_nl_region_notify+0x184/0x1e0 net/core/devlink.c:5158
Code: 38 41 b8 c0 0c 00 00 31 d2 48 89 ee 4c 89 e7 e8 72 1a 26 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e e9 01 bd 41 fa
e8 fc bc 41 fa <0f> 0b e9 f7 fe ff ff e8 f0 bc 41 fa 0f 0b eb da 4c 89 e7 e8 c4 18
RSP: 0018:ffffc90002d6f658 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801f08d580 RSI: ffffffff87344e94 RDI: 0000000000000003
RBP: ffff88801ee42100 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87344d8a R11: 0000000000000000 R12: ffff88801c1dc000
R13: 0000000000000000 R14: 000000000000002c R15: ffff88801c1dc070
FS:  0000555555e8e400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dd7c590310 CR3: 0000000069a09000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 devlink_region_create+0x39f/0x4c0 net/core/devlink.c:10327
 nsim_dev_dummy_region_init drivers/net/netdevsim/dev.c:481 [inline]
 nsim_dev_probe+0x5f6/0x1150 drivers/net/netdevsim/dev.c:1479
 call_driver_probe drivers/base/dd.c:517 [inline]
 really_probe+0x245/0xcc0 drivers/base/dd.c:596
 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:751
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:781
 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:898
 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
 __device_attach+0x228/0x4a0 drivers/base/dd.c:969
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
 device_add+0xc35/0x21b0 drivers/base/core.c:3359
 nsim_bus_dev_new drivers/net/netdevsim/bus.c:435 [inline]
 new_device_store+0x48b/0x770 drivers/net/netdevsim/bus.c:302
 bus_attr_store+0x72/0xa0 drivers/base/bus.c:122
 sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:139
 kernfs_fop_write_iter+0x342/0x500 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2163 [inline]
 new_sync_write+0x429/0x660 fs/read_write.c:507
 vfs_write+0x7cf/0xae0 fs/read_write.c:594
 ksys_write+0x12d/0x250 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f328409d3ef
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01
00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48
RSP: 002b:00007ffdc6851140 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f328409d3ef
RDX: 0000000000000003 RSI: 00007ffdc6851190 RDI: 0000000000000004
RBP: 0000000000000004 R08: 0000000000000000 R09: 00007ffdc68510e0
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f3284144971
R13: 00007ffdc6851190 R14: 0000000000000000 R15: 00007ffdc6851860

Fixes: cf530217 ("devlink: Notify users when objects are accessible")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/2ed1159291f2a589b013914f2b60d8172fc525c1.1632925030.git.leonro@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>