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BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:705 [inline]
BUG: KASAN: use-after-free in queued_spin_lock include/asm-generic/qspinlock.h:82 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock include/linux/spinlock.h:183 [inline]
BUG: KASAN: use-after-free in __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x81/0xe0 kernel/locking/spinlock.c:175
Write of size 4 at addr ffff888105ff1b14 by task kworker/u4:5/392

CPU: 1 PID: 392 Comm: kworker/u4:5 Not tainted 5.10.237-syzkaller-00309-g7e2543346ff7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x280/0x290 mm/kasan/generic.c:189
 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:705 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:82 [inline]
 do_raw_spin_lock include/linux/spinlock.h:183 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x81/0xe0 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 __ip6_del_rt+0x8f/0x150 net/ipv6/route.c:3791
 ip6_del_rt+0xb0/0xf0 net/ipv6/route.c:3807
 __remove_nexthop_fib+0x1e8/0x260 net/ipv4/nexthop.c:885
 __remove_nexthop net/ipv4/nexthop.c:893 [inline]
 remove_nexthop+0x75/0x4d0 net/ipv4/nexthop.c:919
 remove_nh_grp_entry net/ipv4/nexthop.c:797 [inline]
 remove_nexthop_from_groups+0x193/0xe40 net/ipv4/nexthop.c:846
 __remove_nexthop net/ipv4/nexthop.c:904 [inline]
 remove_nexthop+0x38a/0x4d0 net/ipv4/nexthop.c:919
 flush_all_nexthops net/ipv4/nexthop.c:1237 [inline]
 nexthop_net_exit+0x3a/0xa0 net/ipv4/nexthop.c:2012
 ops_exit_list net/core/net_namespace.c:185 [inline]
 cleanup_net+0x586/0xb70 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Allocated by task 1617:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 ____kasan_kmalloc mm/kasan/common.c:509 [inline]
 __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518
 kasan_kmalloc include/linux/kasan.h:254 [inline]
 kmem_cache_alloc_trace+0x184/0x2e0 mm/slub.c:2974
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 fib6_net_init+0x217/0x880 net/ipv6/ip6_fib.c:2376
 ops_init+0x1ba/0x4a0 net/core/net_namespace.c:144
 setup_net+0x36d/0xb50 net/core/net_namespace.c:345
 copy_net_ns+0x314/0x520 net/core/net_namespace.c:486
 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:231
 ksys_unshare+0x4ac/0x7d0 kernel/fork.c:3080
 __do_sys_unshare kernel/fork.c:3148 [inline]
 __se_sys_unshare kernel/fork.c:3146 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3146
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 392:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1595 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kfree+0xc0/0x270 mm/slub.c:4191
 fib6_free_table net/ipv6/ip6_fib.c:214 [inline]
 fib6_net_exit+0x270/0x300 net/ipv6/ip6_fib.c:2430
 ops_exit_list net/core/net_namespace.c:185 [inline]
 cleanup_net+0x586/0xb70 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x105/0x1040 kernel/rcu/tree.c:3050
 tnode_free net/ipv4/fib_trie.c:495 [inline]
 replace+0x1a1/0x450 net/ipv4/fib_trie.c:521
 inflate net/ipv4/fib_trie.c:623 [inline]
 resize+0x10ec/0x2450 net/ipv4/fib_trie.c:868
 trie_rebalance net/ipv4/fib_trie.c:1059 [inline]
 fib_insert_node net/ipv4/fib_trie.c:1103 [inline]
 fib_insert_alias+0x98f/0x1020 net/ipv4/fib_trie.c:1117
 fib_trie_unmerge+0x5ba/0x14c0 net/ipv4/fib_trie.c:1887
 fib_unmerge+0xc5/0x360 net/ipv4/fib_frontend.c:160
 fib4_rule_delete+0x48/0x390 net/ipv4/fib_rules.c:293
 fib_nl_delrule+0x1564/0x1cb0 net/core/fib_rules.c:907
 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2485
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628
 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline]
 netlink_unicast+0x87c/0xa40 net/netlink/af_netlink.c:1333
 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888105ff1b00
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 20 bytes inside of
 128-byte region [ffff888105ff1b00, ffff888105ff1b80)
The buggy address belongs to the page:
page:ffffea000417fc40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x105ff1
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea0004217f40 0000000300000003 ffff888100043500
raw: 0000000000000000 0000000000100010 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 1323866612, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5349
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc_trace+0x1b3/0x2e0 mm/slub.c:2972
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 call_usermodehelper_setup+0x71/0x1d0 kernel/umh.c:363
 kobject_uevent_env+0x639/0x700 lib/kobject_uevent.c:629
 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657
 device_add+0x7bb/0xbf0 drivers/base/core.c:3254
 pci_device_add+0x11bf/0x19f0 drivers/pci/probe.c:2515
 pci_scan_single_device+0x36b/0x440 drivers/pci/probe.c:2533
 pci_scan_slot+0x19b/0x780 drivers/pci/probe.c:2608
 pci_scan_child_bus_extend+0x7c/0x820 drivers/pci/probe.c:2825
 pci_scan_child_bus+0x17/0x20 drivers/pci/probe.c:2955
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888105ff1a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888105ff1a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888105ff1b00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888105ff1b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888105ff1c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
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