================================================================== BUG: KASAN: slab-use-after-free in rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 Read of size 1 at addr ffff8880393454a8 by task ksoftirqd/1/30 CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x330 kernel/locking/lockdep.c:5842 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock include/linux/spinlock_rt.h:45 [inline] __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124 blk_update_request+0x57e/0xe60 block/blk-mq.c:1019 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1181 blk_complete_reqs block/blk-mq.c:1256 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1261 handle_softirqs+0x1de/0x640 kernel/softirq.c:622 run_ksoftirqd+0x52/0x180 kernel/softirq.c:1063 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6020: 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+0x3a6/0x690 mm/slub.c:5297 kmalloc_noprof include/linux/slab.h:962 [inline] lbmLogInit fs/jfs/jfs_logmgr.c:1821 [inline] lmLogInit+0x3e5/0x1a00 fs/jfs/jfs_logmgr.c:1269 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline] lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069 jfs_mount_rw+0xee/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6020: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 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:2670 [inline] slab_free mm/slub.c:6082 [inline] kfree+0x1c1/0x690 mm/slub.c:6399 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline] lmLogInit+0x114c/0x1a00 fs/jfs/jfs_logmgr.c:1415 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline] lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069 jfs_mount_rw+0xee/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888039345400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 168 bytes inside of freed 256-byte region [ffff888039345400, ffff888039345500) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x39344 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe0db40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe0db40 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000001 ffffea0000e4d101 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5809, tgid 5809 (syz-executor), ts 88409000343, free_ts 88380138033 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3950 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5245 alloc_slab_page mm/slub.c:3238 [inline] allocate_slab+0x77/0x660 mm/slub.c:3411 new_slab mm/slub.c:3469 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7091 refill_sheaf mm/slub.c:2787 [inline] __pcs_replace_empty_main+0x328/0x5f0 mm/slub.c:4536 alloc_from_pcs mm/slub.c:4639 [inline] slab_alloc_node mm/slub.c:4773 [inline] __do_kmalloc_node mm/slub.c:5176 [inline] __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5189 kmalloc_noprof include/linux/slab.h:966 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] fib_create_info+0x171d/0x31f0 net/ipv4/fib_semantics.c:1402 fib_table_insert+0xc8/0x1b50 net/ipv4/fib_trie.c:1212 fib_magic+0x434/0x510 net/ipv4/fib_frontend.c:1134 fib_add_ifaddr+0x144/0x5f0 net/ipv4/fib_frontend.c:1156 fib_netdev_event+0x382/0x490 net/ipv4/fib_frontend.c:1516 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2281 [inline] call_netdevice_notifiers net/core/dev.c:2295 [inline] __dev_notify_flags+0x1a9/0x310 net/core/dev.c:9788 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9817 do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3158 page last free pid 1003 tgid 1003 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xfd0/0x1160 mm/page_alloc.c:2973 __slab_free+0x24f/0x2a0 mm/slub.c:5490 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4459 [inline] slab_alloc_node mm/slub.c:4788 [inline] kmem_cache_alloc_node_noprof+0x22a/0x6e0 mm/slub.c:4840 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:586 __alloc_skb+0x204/0x390 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] inet6_ifmcaddr_notify+0xfa/0x1e0 net/ipv6/mcast.c:909 __ipv6_dev_mc_inc+0x8a9/0xa50 net/ipv6/mcast.c:973 addrconf_join_solict net/ipv6/addrconf.c:2246 [inline] addrconf_dad_begin net/ipv6/addrconf.c:4099 [inline] addrconf_dad_work+0x5cf/0x1680 net/ipv6/addrconf.c:4227 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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: ffff888039345380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888039345400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888039345480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888039345500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888039345580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================