================================================================== BUG: KASAN: slab-use-after-free in kobject_uevent_net_broadcast lib/kobject_uevent.c:415 [inline] BUG: KASAN: slab-use-after-free in kobject_uevent_env+0x1383/0x18b0 lib/kobject_uevent.c:611 Read of size 8 at addr ffff888075111e50 by task kworker/u8:6/376 CPU: 0 UID: 0 PID: 376 Comm: kworker/u8:6 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Workqueue: ib-unreg-wq ib_unregister_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 kobject_uevent_net_broadcast lib/kobject_uevent.c:415 [inline] kobject_uevent_env+0x1383/0x18b0 lib/kobject_uevent.c:611 device_del+0x605/0x9b0 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+0x1ea/0x280 drivers/infiniband/core/device.c:1339 __ib_unregister_device+0x2b4/0x480 drivers/infiniband/core/device.c:1571 ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1683 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 17282: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] uevent_net_init+0xd3/0x330 lib/kobject_uevent.c:782 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x118/0x3a0 net/core/net_namespace.c:443 copy_net_ns+0x345/0x7a0 net/core/net_namespace.c:582 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234 ksys_unshare+0x4a2/0xa70 kernel/fork.c:3297 __do_sys_unshare kernel/fork.c:3361 [inline] __se_sys_unshare kernel/fork.c:3359 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3359 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12948: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5f/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+0x22b/0x6d0 mm/slub.c:6802 ops_exit_list net/core/net_namespace.c:200 [inline] ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:253 cleanup_net+0x499/0x920 net/core/net_namespace.c:706 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888075111e40 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 16 bytes inside of freed 32-byte region [ffff888075111e40, ffff888075111e60) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888075111480 pfn:0x75111 flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000200 ffff88801c031780 ffffea0000a7fed0 ffffea0000d06a10 raw: ffff888075111480 0000000000400031 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 59, tgid 59 (kworker/u8:4), ts 232463073964 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab mm/slub.c:3462 [inline] new_slab+0xa9/0x6e0 mm/slub.c:3513 refill_objects+0xe3/0x410 mm/slub.c:7418 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] batadv_mcast_mla_meshif_get_ipv4 net/batman-adv/multicast.c:403 [inline] batadv_mcast_mla_meshif_get net/batman-adv/multicast.c:531 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:912 [inline] batadv_mcast_mla_update+0x1ed0/0x3200 net/batman-adv/multicast.c:949 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 15 tgid 15 ts 232425340736 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 __pagetable_free include/linux/mm.h:3804 [inline] pagetable_free include/linux/mm.h:3828 [inline] pagetable_dtor_free include/linux/mm.h:3927 [inline] __tlb_remove_table include/asm-generic/tlb.h:221 [inline] __tlb_remove_table_free mm/mmu_gather.c:228 [inline] tlb_remove_table_rcu+0x2cf/0x380 mm/mmu_gather.c:291 rcu_do_batch kernel/rcu/tree.c:2650 [inline] rcu_core+0x5f0/0x1260 kernel/rcu/tree.c:2919 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645 run_ksoftirqd kernel/softirq.c:1099 [inline] run_ksoftirqd+0x38/0x60 kernel/softirq.c:1091 smpboot_thread_fn+0x3d3/0xab0 kernel/smpboot.c:160 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888075111d00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff888075111d80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff888075111e00: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff888075111e80: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc ffff888075111f00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ==================================================================