BUG: KASAN: slab-use-after-free in handle_tx+0x1ec/0x610 drivers/net/caif/caif_serial.c:222 Read of size 8 at addr ffff888034b4a020 by task aoe_tx0/1321 CPU: 0 UID: 0 PID: 1321 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 handle_tx+0x1ec/0x610 drivers/net/caif/caif_serial.c:222 __netdev_start_xmit include/linux/netdevice.h:5248 [inline] netdev_start_xmit include/linux/netdevice.h:5257 [inline] xmit_one net/core/dev.c:3845 [inline] dev_hard_start_xmit+0x2f0/0x870 net/core/dev.c:3861 __dev_queue_xmit+0x1b50/0x3b70 net/core/dev.c:4763 dev_queue_xmit include/linux/netdevice.h:3365 [inline] tx+0x6b/0x190 drivers/block/aoe/aoenet.c:62 kthread+0x1d0/0x3e0 drivers/block/aoe/aoecmd.c:1241 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 10777: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x1ef/0x6c0 mm/slub.c:5725 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] alloc_tty_struct+0xa6/0x7c0 drivers/tty/tty_io.c:3102 tty_init_dev+0x59/0x4d0 drivers/tty/tty_io.c:1400 tty_open_by_driver drivers/tty/tty_io.c:2073 [inline] tty_open+0x5b2/0xd10 drivers/tty/tty_io.c:2120 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x9b1/0x1350 fs/open.c:965 vfs_open+0x3b/0x350 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ef1/0x3840 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5806: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2515 [inline] slab_free mm/slub.c:6574 [inline] kfree+0x197/0x950 mm/slub.c:6781 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559 insert_work+0x3d/0x330 kernel/workqueue.c:2186 __queue_work+0xd63/0x1010 kernel/workqueue.c:2341 queue_work_on+0x181/0x270 kernel/workqueue.c:2392 tty_release_struct+0xb8/0xd0 drivers/tty/tty_io.c:1692 tty_release+0xcb6/0x1650 drivers/tty/tty_io.c:1852 __fput+0x45b/0xa80 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x125d/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888034b4a000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 32 bytes inside of freed 2048-byte region [ffff888034b4a000, ffff888034b4a800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888034b48000 pfn:0x34b48 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff8880593def01 flags: 0x80000000000240(workingset|head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000240 ffff88813ff303c0 ffffea0000b4c810 ffffea0001709610 raw: ffff888034b48000 0000000000080007 00000000f5000000 ffff8880593def01 head: 0080000000000240 ffff88813ff303c0 ffffea0000b4c810 ffffea0001709610 head: ffff888034b48000 0000000000080007 00000000f5000000 ffff8880593def01 head: 0080000000000003 ffffea0000d2d201 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 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 5821, tgid 5821 (syz-executor), ts 93923349812, free_ts 93552285776 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3031 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3204 new_slab mm/slub.c:3258 [inline] ___slab_alloc+0xb12/0x13f0 mm/slub.c:4628 __slab_alloc+0xc6/0x1f0 mm/slub.c:4747 __slab_alloc_node mm/slub.c:4823 [inline] slab_alloc_node mm/slub.c:5234 [inline] __do_kmalloc_node mm/slub.c:5603 [inline] __kmalloc_node_track_caller_noprof+0x2a8/0x7e0 mm/slub.c:5713 kmemdup_noprof+0x2b/0x70 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:765 [inline] __devinet_sysctl_register+0xa5/0x470 net/ipv4/devinet.c:2665 devinet_sysctl_register+0x187/0x200 net/ipv4/devinet.c:2717 inetdev_init+0x2b4/0x500 net/ipv4/devinet.c:291 inetdev_event+0x301/0x15b0 net/ipv4/devinet.c:1590 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] register_netdevice+0x163c/0x1b10 net/core/dev.c:11332 hsr_dev_finalize+0x651/0xab0 net/hsr/hsr_device.c:759 page last free pid 5809 tgid 5809 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xfb6/0x1140 mm/page_alloc.c:2906 discard_slab mm/slub.c:3302 [inline] __put_partials+0x149/0x170 mm/slub.c:3849 __slab_free+0x29e/0x370 mm/slub.c:5883 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4947 [inline] slab_alloc_node mm/slub.c:5246 [inline] __kmalloc_cache_noprof+0x181/0x6c0 mm/slub.c:5720 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ref_tracker_alloc+0x13b/0x450 lib/ref_tracker.c:271 register_netdevice+0x14d7/0x1b10 net/core/dev.c:11318 veth_newlink+0x5d4/0xa60 drivers/net/veth.c:1884 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3833 __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0x16e4/0x1c80 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6954 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x843/0xa10 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 Memory state around the buggy address: ffff888034b49f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888034b49f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888034b4a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888034b4a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888034b4a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================