================================================================== BUG: KASAN: slab-use-after-free in handle_tx+0x1ec/0x610 drivers/net/caif/caif_serial.c:222 Read of size 8 at addr ffff88801ff3b020 by task aoe_tx0/1300 CPU: 0 UID: 0 PID: 1300 Comm: aoe_tx0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:5288 [inline] netdev_start_xmit include/linux/netdevice.h:5297 [inline] xmit_one net/core/dev.c:3854 [inline] dev_hard_start_xmit+0x2cd/0x800 net/core/dev.c:3870 __dev_queue_xmit+0x1493/0x3140 net/core/dev.c:4818 dev_queue_xmit include/linux/netdevice.h:3387 [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+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 21837: 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+0x3e2/0x700 mm/slub.c:5780 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] alloc_tty_struct+0xa6/0x780 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+0x5a6/0xd10 drivers/tty/tty_io.c:2120 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x785/0x14e0 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4627 [inline] path_openat+0x2de0/0x3840 fs/namei.c:4786 do_filp_open+0x1fa/0x410 fs/namei.c:4813 do_sys_openat2+0x121/0x200 fs/open.c:1391 do_sys_open fs/open.c:1397 [inline] __do_sys_openat fs/open.c:1413 [inline] __se_sys_openat fs/open.c:1408 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1408 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5832: 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:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x1c0/0x660 mm/slub.c:6882 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2199 __queue_work+0xcd0/0xf90 kernel/workqueue.c:2354 queue_work_on+0x181/0x270 kernel/workqueue.c:2405 tty_release_struct+0xb8/0xd0 drivers/tty/tty_io.c:1692 tty_release+0xcb0/0x1720 drivers/tty/tty_io.c:1852 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8bd/0x25b0 kernel/exit.c:971 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801ff3b000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 32 bytes inside of freed 2048-byte region [ffff88801ff3b000, ffff88801ff3b800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ff38 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88802ec71d81 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe303c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 ffff88802ec71d81 head: 00fff00000000040 ffff88813fe303c0 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 ffff88802ec71d81 head: 00fff00000000003 ffffea00007fce01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 5824, tgid 5824 (syz-executor), ts 74346809690, free_ts 72613715578 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857 prep_new_page mm/page_alloc.c:1865 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xf2b/0x1960 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5255 [inline] __do_kmalloc_node mm/slub.c:5660 [inline] __kmalloc_node_track_caller_noprof+0x5d4/0x820 mm/slub.c:5768 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_init_net+0x391/0x7c0 net/ipv4/devinet.c:2810 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0x110/0x330 net/core/net_namespace.c:446 copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:226 page last free pid 5814 tgid 5814 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 __folio_put+0x21b/0x2c0 mm/swap.c:112 put_netmem net/core/skbuff.c:7417 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x49a/0x7c0 net/core/skbuff.c:1101 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb+0x55/0x70 net/core/skbuff.c:1196 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3494 [inline] tcp_ack+0x2341/0x6a30 net/ipv4/tcp_input.c:4119 tcp_rcv_established+0x13de/0x2580 net/ipv4/tcp_input.c:6374 tcp_v4_do_rcv+0xa90/0x1430 net/ipv4/tcp_ipv4.c:1881 sk_backlog_rcv include/net/sock.h:1177 [inline] __release_sock+0x265/0x3a0 net/core/sock.c:3213 __sk_flush_backlog+0x36/0xc0 net/core/sock.c:3236 sk_flush_backlog include/net/sock.h:1240 [inline] tcp_sendmsg_locked+0x412f/0x5520 net/ipv4/tcp.c:1213 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1412 sock_sendmsg_nosec+0x128/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] sock_write_iter+0x2d9/0x3d0 net/socket.c:1210 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff88801ff3af00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801ff3af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801ff3b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801ff3b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801ff3b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================