================================================================== BUG: KASAN: slab-use-after-free in kobject_uevent_net_broadcast+0x12c/0x560 lib/kobject_uevent.c:415 Read of size 8 at addr ffff8880578d3b90 by task kworker/u8:5/60 CPU: 0 UID: 0 PID: 60 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Workqueue: ib-unreg-wq ib_unregister_work Call Trace: 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+0x248/0x330 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 Allocated by task 16037: 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:409 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426 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+0x1ec4/0x4400 kernel/fork.c:2314 kernel_clone+0x2d7/0x940 kernel/fork.c:2771 __do_sys_clone kernel/fork.c:2913 [inline] __se_sys_clone kernel/fork.c:2897 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2897 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 16037: 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:264 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x1c5/0x650 mm/slub.c:6802 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+0x1ec4/0x4400 kernel/fork.c:2314 kernel_clone+0x2d7/0x940 kernel/fork.c:2771 __do_sys_clone kernel/fork.c:2913 [inline] __se_sys_clone kernel/fork.c:2897 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2897 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 ffff8880578d3b80 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 16 bytes inside of freed 32-byte region [ffff8880578d3b80, ffff8880578d3ba0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x578d3 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b041780 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000400040 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 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6844, tgid 6844 (dhcpcd-run-hook), ts 111174802590 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:7418 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] __kmalloc_cache_noprof+0x39b/0x600 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6509 [inline] kmem_cache_free+0x156/0x650 mm/slub.c:6636 tear_down_vmas+0x31f/0x530 mm/mmap.c:1277 exit_mmap+0x4ca/0x9f0 mm/mmap.c:1335 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x18e/0x240 kernel/exit.c:592 do_exit+0x6cd/0x2360 kernel/exit.c:974 do_group_exit+0x22d/0x2f0 kernel/exit.c:1129 __do_sys_exit_group kernel/exit.c:1140 [inline] __se_sys_exit_group kernel/exit.c:1138 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1138 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 page last free pid 6844 tgid 6844 ts 111173475708 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+0x18e/0x240 kernel/exit.c:592 do_exit+0x6cd/0x2360 kernel/exit.c:974 do_group_exit+0x22d/0x2f0 kernel/exit.c:1129 __do_sys_exit_group kernel/exit.c:1140 [inline] __se_sys_exit_group kernel/exit.c:1138 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1138 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 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 Memory state around the buggy address: ffff8880578d3a80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ffff8880578d3b00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff8880578d3b80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff8880578d3c00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff8880578d3c80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================