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BUG: KASAN: slab-use-after-free in kobject_uevent_net_broadcast+0x12c/0x560 lib/kobject_uevent.c:415
Read of size 8 at addr ffff88807e44f9d0 by task kworker/u8:48/7860

CPU: 1 UID: 0 PID: 7860 Comm: kworker/u8:48 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: ib-unreg-wq ib_unregister_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 kobject_uevent_net_broadcast+0x12c/0x560 lib/kobject_uevent.c:415
 kobject_uevent_env+0x566/0x9e0 lib/kobject_uevent.c:611
 device_del+0x74d/0x8f0 drivers/base/core.c:3983
 remove_one_compat_dev drivers/infiniband/core/device.c:1036 [inline]
 remove_compat_devs drivers/infiniband/core/device.c:1047 [inline]
 disable_device+0x248/0x3 drivers/infiniband/core/device.c:1339
 remove_one_compat_dev drivers/infiniband/core/device.c:1036 [inline]
 remove_compat_devs drivers/infiniband/core/device.c:1047 [inline]
 disable_device+0x248/0x330 drivers/infiniband/core/device.c:1339
 __ib_unregister_device+0x2c9/0x400 drivers/infiniband/core/device.c:1571
 ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1683
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 18215:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 uevent_net_init+0xdb/0x2d0 lib/kobject_uevent.c:782
 ops_init+0x35d/0x5d0 net/core/net_namespace.c:137
 setup_net+0x118/0x350 net/core/net_namespace.c:443
 copy_net_ns+0x53b/0x780 net/core/net_namespace.c:582
 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132
 copy_namespaces+0x432/0x4b0 kernel/nsproxy.c:195
 copy_process+0x1ec0/0x43e0 kernel/fork.c:2310
 kernel_clone+0x2d7/0x940 kernel/fork.c:2766
 __do_sys_clone kernel/fork.c:2908 [inline]
 __se_sys_clone kernel/fork.c:2892 [inline]
 __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2892
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 18215:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6792
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:253
 setup_net+0x2f6/0x350 net/core/net_namespace.c:459
 copy_net_ns+0x53b/0x780 net/core/net_namespace.c:582
 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132
 copy_namespaces+0x432/0x4b0 kernel/nsproxy.c:195
 copy_process+0x1ec0/0x43e0 kernel/fork.c:2310
 kernel_clone+0x2d7/0x940 kernel/fork.c:2766
 __do_sys_clone kernel/fork.c:2908 [inline]
 __se_sys_clone kernel/fork.c:2892 [inline]
 __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2892
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807e44f9c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 16 bytes inside of
 freed 32-byte region [ffff88807e44f9c0, ffff88807e44f9e0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807e44f840 pfn:0x7e44f
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88801b041780 ffffea00016264d0 ffffea0001d77590
raw: ffff88807e44f840 000000000040003e 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5612, tgid 5612 (syz-executor), ts 292239239703
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7410
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_noprof+0x47b/0x720 mm/slub.c:5439
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x2ad/0x570 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x5fa/0x640 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827
 security_inode_getattr+0x12b/0x310 security/security.c:1895
 vfs_getattr+0x23/0x70 fs/stat.c:259
 vfs_statx_path+0x2b/0x230 fs/stat.c:299
 vfs_statx+0x12e/0x200 fs/stat.c:356
 vfs_fstatat+0x11b/0x170 fs/stat.c:373
 __do_sys_newfstatat fs/stat.c:538 [inline]
 __se_sys_newfstatat fs/stat.c:532 [inline]
 __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532
page last free pid 11162 tgid 11151 ts 292233858623 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
 tlb_batch_list_free mm/mmu_gather.c:161 [inline]
 tlb_finish_mmu+0x13e/0x220 mm/mmu_gather.c:552
 exit_mmap+0x4b2/0x9f0 mm/mmap.c:1328
 __mmput+0x118/0x420 kernel/fork.c:1193
 exit_mm+0x221/0x2d0 kernel/exit.c:614
 do_exit+0x6cd/0x2360 kernel/exit.c:996
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151
 get_signal+0x121b/0x12c0 kernel/signal.c:3039
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807e44f880: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff88807e44f900: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
>ffff88807e44f980: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
                                                 ^
 ffff88807e44fa00: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff88807e44fa80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
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