================================================================== BUG: KASAN: use-after-free in handle_tx+0x1ed/0x600 drivers/net/caif/caif_serial.c:236 Read of size 8 at addr ffff888074af9018 by task aoe_tx0/1276 CPU: 0 PID: 1276 Comm: aoe_tx0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 handle_tx+0x1ed/0x600 drivers/net/caif/caif_serial.c:236 __netdev_start_xmit include/linux/netdevice.h:4896 [inline] netdev_start_xmit include/linux/netdevice.h:4910 [inline] xmit_one net/core/dev.c:3670 [inline] dev_hard_start_xmit+0x262/0x870 net/core/dev.c:3686 __dev_queue_xmit+0x1bf1/0x3760 net/core/dev.c:4346 dev_queue_xmit include/linux/netdevice.h:3051 [inline] tx+0x67/0x170 drivers/block/aoe/aoenet.c:63 kthread+0x1c6/0x3b0 drivers/block/aoe/aoecmd.c:1241 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 5011: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] alloc_tty_struct+0xa6/0x740 drivers/tty/tty_io.c:3089 tty_init_dev+0x55/0x4c0 drivers/tty/tty_io.c:1408 tty_open_by_driver drivers/tty/tty_io.c:2081 [inline] tty_open+0x5a3/0xd00 drivers/tty/tty_io.c:2128 chrdev_open+0x597/0x670 fs/char_dev.c:414 do_dentry_open+0x7e9/0x10d0 fs/open.c:882 do_open fs/namei.c:3626 [inline] path_openat+0x25c6/0x2e70 fs/namei.c:3783 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810 do_sys_openat2+0x142/0x490 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 5300: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3c0 kernel/workqueue.c:1361 __queue_work+0xba3/0xfb0 kernel/workqueue.c:1520 queue_work_on+0x11d/0x1d0 kernel/workqueue.c:1548 tty_release_struct+0xb4/0xd0 drivers/tty/tty_io.c:1700 tty_release+0xc72/0x1600 drivers/tty/tty_io.c:1860 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x93e/0x2400 kernel/exit.c:880 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x154/0x980 kernel/rcu/tree.c:2849 in6_dev_put include/net/addrconf.h:388 [inline] addrconf_ifdown+0x178f/0x1a10 net/ipv6/addrconf.c:3954 addrconf_notify+0x405/0xf40 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] unregister_netdevice_many+0xfdc/0x1840 net/core/dev.c:10990 vti6_exit_batch_net+0x3c6/0x410 net/ipv6/ip6_vti.c:1191 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:640 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888074af9000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 24 bytes inside of 2048-byte region [ffff888074af9000, ffff888074af9800) The buggy address belongs to the physical page: page:ffffea0001d2be00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x74af8 head:ffffea0001d2be00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801b2bca01 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001520600 dead000000000002 ffff88801744c140 raw: 0000000000000000 0000000000080008 00000001ffffffff ffff88801b2bca01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4267, tgid 4267 (syz-executor), ts 73468427767, free_ts 73457862095 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1230 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] ipv6_add_dev+0xf8/0x1120 net/ipv6/addrconf.c:379 addrconf_notify+0x634/0xf40 net/ipv6/addrconf.c:3595 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] register_netdevice+0x1600/0x1aa0 net/core/dev.c:10237 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x35f/0x410 drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x695/0xaf0 drivers/net/netdevsim/dev.c:1396 nsim_dev_port_add_all+0x35/0xe0 drivers/net/netdevsim/dev.c:1454 nsim_drv_probe+0x814/0xaf0 drivers/net/netdevsim/dev.c:1608 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3390 alloc_inode_sb include/linux/fs.h:3245 [inline] alloc_inode fs/inode.c:263 [inline] new_inode_pseudo+0x7e/0x1c0 fs/inode.c:1063 new_inode+0x25/0x1c0 fs/inode.c:1091 debugfs_get_inode fs/debugfs/inode.c:72 [inline] __debugfs_create_file+0x148/0x510 fs/debugfs/inode.c:432 nsim_ethtool_init+0x277/0x3e0 drivers/net/netdevsim/ethtool.c:187 nsim_create+0x1d1/0x410 drivers/net/netdevsim/netdev.c:363 __nsim_dev_port_add+0x695/0xaf0 drivers/net/netdevsim/dev.c:1396 nsim_dev_port_add_all+0x35/0xe0 drivers/net/netdevsim/dev.c:1454 Memory state around the buggy address: ffff888074af8f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888074af8f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888074af9000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888074af9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888074af9100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================