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BUG: KASAN: use-after-free in dev_put include/linux/netdevice.h:3982 [inline]
BUG: KASAN: use-after-free in netdevice_event_work_handler+0x15b/0x1b0 drivers/infiniband/core/roce_gid_mgmt.c:630
Read of size 8 at addr ffff8880151f6568 by task kworker/u4:8/19628

CPU: 1 PID: 19628 Comm: kworker/u4:8 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: gid-cache-wq netdevice_event_work_handler
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:396 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413
 dev_put include/linux/netdevice.h:3982 [inline]
 netdevice_event_work_handler+0x15b/0x1b0 drivers/infiniband/core/roce_gid_mgmt.c:630
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Allocated by task 20173:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:401 [inline]
 ____kasan_kmalloc.constprop.0+0x7f/0xa0 mm/kasan/common.c:429
 kmalloc_node include/linux/slab.h:575 [inline]
 kvmalloc_node+0x61/0xf0 mm/util.c:587
 kvmalloc include/linux/mm.h:781 [inline]
 kvzalloc include/linux/mm.h:789 [inline]
 alloc_netdev_mqs+0x97/0xea0 net/core/dev.c:10540
 __ip_tunnel_create+0x201/0x5c0 net/ipv4/ip_tunnel.c:254
 ip_tunnel_init_net+0x330/0x9d0 net/ipv4/ip_tunnel.c:1063
 ops_init+0xaf/0x470 net/core/net_namespace.c:152
 setup_net+0x2de/0x850 net/core/net_namespace.c:342
 copy_net_ns+0x31e/0x760 net/core/net_namespace.c:483
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x8e0 kernel/fork.c:2957
 __do_sys_unshare kernel/fork.c:3025 [inline]
 __se_sys_unshare kernel/fork.c:3023 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3023
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 20173:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:356
 ____kasan_slab_free+0xb0/0xe0 mm/kasan/common.c:362
 kasan_slab_free include/linux/kasan.h:188 [inline]
 __cache_free mm/slab.c:3424 [inline]
 kfree+0xed/0x270 mm/slab.c:3760
 kvfree+0x42/0x50 mm/util.c:616
 device_release+0x9f/0x240 drivers/base/core.c:1962
 kobject_cleanup lib/kobject.c:705 [inline]
 kobject_release lib/kobject.c:736 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1c8/0x540 lib/kobject.c:753
 put_device+0x1b/0x30 drivers/base/core.c:3190
 free_netdev+0x3a2/0x4c0 net/core/dev.c:10660
 __ip_tunnel_create+0x4d1/0x5c0 net/ipv4/ip_tunnel.c:274
 ip_tunnel_init_net+0x330/0x9d0 net/ipv4/ip_tunnel.c:1063
 ops_init+0xaf/0x470 net/core/net_namespace.c:152
 setup_net+0x2de/0x850 net/core/net_namespace.c:342
 copy_net_ns+0x31e/0x760 net/core/net_namespace.c:483
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x8e0 kernel/fork.c:2957
 __do_sys_unshare kernel/fork.c:3025 [inline]
 __se_sys_unshare kernel/fork.c:3023 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3023
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880151f6000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1384 bytes inside of
 4096-byte region [ffff8880151f6000, ffff8880151f7000)
The buggy address belongs to the page:
page:00000000bc4daf7d refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x151f6
head:00000000bc4daf7d order:1 compound_mapcount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 ffffea00018c1288 ffffea0001db2e88 ffff888010040900
raw: 0000000000000000 ffff8880151f6000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880151f6400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880151f6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880151f6500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff8880151f6580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880151f6600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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