================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline] BUG: KASAN: use-after-free in atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline] BUG: KASAN: use-after-free in __down_read_trylock kernel/locking/rwsem.c:1393 [inline] BUG: KASAN: use-after-free in down_read_trylock+0x89/0x160 kernel/locking/rwsem.c:1553 Write of size 8 at addr ffff888115738070 by task kworker/u4:1/9 CPU: 0 PID: 9 Comm: kworker/u4:1 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 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+0x249/0x2a0 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] atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline] atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline] __down_read_trylock kernel/locking/rwsem.c:1393 [inline] down_read_trylock+0x89/0x160 kernel/locking/rwsem.c:1553 trylock_super+0x1f/0xf0 fs/super.c:418 __writeback_inodes_wb fs/fs-writeback.c:1795 [inline] wb_writeback+0x4a5/0xbe0 fs/fs-writeback.c:1910 wb_check_background_flush fs/fs-writeback.c:1978 [inline] wb_do_writeback fs/fs-writeback.c:2066 [inline] wb_workfn+0xb0a/0xf30 fs/fs-writeback.c:2094 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13c0 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 2206: 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+0x181/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] kobject_uevent_env+0x272/0x700 lib/kobject_uevent.c:539 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 rx_queue_add_kobject net/core/net-sysfs.c:1029 [inline] net_rx_queue_update_kobjects+0x1ec/0x420 net/core/net-sysfs.c:1069 register_queue_kobjects net/core/net-sysfs.c:1750 [inline] netdev_register_kobject+0x26b/0x360 net/core/net-sysfs.c:2001 register_netdevice+0xdf0/0x13e0 net/core/dev.c:10069 veth_newlink+0x853/0xb60 drivers/net/veth.c:1387 __rtnl_newlink net/core/rtnetlink.c:3482 [inline] rtnl_newlink+0x1310/0x18f0 net/core/rtnetlink.c:3530 rtnetlink_rcv_msg+0xa31/0xcc0 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x89c/0xb50 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] __sys_sendto+0x467/0x620 net/socket.c:2006 __do_sys_sendto net/socket.c:2018 [inline] __se_sys_sendto net/socket.c:2014 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2014 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 2206: 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:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 kobject_uevent_env+0x34d/0x700 lib/kobject_uevent.c:641 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 rx_queue_add_kobject net/core/net-sysfs.c:1029 [inline] net_rx_queue_update_kobjects+0x1ec/0x420 net/core/net-sysfs.c:1069 register_queue_kobjects net/core/net-sysfs.c:1750 [inline] netdev_register_kobject+0x26b/0x360 net/core/net-sysfs.c:2001 register_netdevice+0xdf0/0x13e0 net/core/dev.c:10069 veth_newlink+0x853/0xb60 drivers/net/veth.c:1387 __rtnl_newlink net/core/rtnetlink.c:3482 [inline] rtnl_newlink+0x1310/0x18f0 net/core/rtnetlink.c:3530 rtnetlink_rcv_msg+0xa31/0xcc0 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x89c/0xb50 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] __sys_sendto+0x467/0x620 net/socket.c:2006 __do_sys_sendto net/socket.c:2018 [inline] __se_sys_sendto net/socket.c:2014 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2014 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 ffff888115738000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 112 bytes inside of 4096-byte region [ffff888115738000, ffff888115739000) The buggy address belongs to the page: page:ffffea000455ce00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115738 head:ffffea000455ce00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042c00 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 2206, ts 101361096296, free_ts 101354029958 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+0x223b/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc_trace+0x1b0/0x2e0 mm/slub.c:2977 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] kobject_uevent_env+0x272/0x700 lib/kobject_uevent.c:539 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657 rx_queue_add_kobject net/core/net-sysfs.c:1029 [inline] net_rx_queue_update_kobjects+0x1ec/0x420 net/core/net-sysfs.c:1069 register_queue_kobjects net/core/net-sysfs.c:1750 [inline] netdev_register_kobject+0x26b/0x360 net/core/net-sysfs.c:2001 register_netdevice+0xdf0/0x13e0 net/core/dev.c:10069 veth_newlink+0x853/0xb60 drivers/net/veth.c:1387 __rtnl_newlink net/core/rtnetlink.c:3482 [inline] rtnl_newlink+0x1310/0x18f0 net/core/rtnetlink.c:3530 rtnetlink_rcv_msg+0xa31/0xcc0 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2503 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5445 [inline] __free_pages+0xd8/0x3b0 mm/page_alloc.c:5454 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab+0x29/0x40 mm/slub.c:1920 __slab_free+0x313/0x3a0 mm/slub.c:3136 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x162/0x2d0 mm/slub.c:2965 kmem_cache_alloc_node include/linux/slab.h:426 [inline] __alloc_skb+0x9e/0x520 net/core/skbuff.c:200 alloc_skb include/linux/skbuff.h:1126 [inline] nlmsg_new include/net/netlink.h:953 [inline] inet6_netconf_notify_devconf+0xd6/0x190 net/ipv6/addrconf.c:579 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7097 [inline] addrconf_sysctl_unregister net/ipv6/addrconf.c:7121 [inline] addrconf_ifdown+0x1592/0x1850 net/ipv6/addrconf.c:3940 addrconf_notify+0x3bd/0xe90 net/ipv6/addrconf.c:-1 Memory state around the buggy address: ffff888115737f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888115737f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888115738000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888115738080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888115738100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================