syzbot

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BUG: KASAN: slab-use-after-free in uart_write_room+0x85e/0x940 drivers/tty/serial/serial_core.c:642
Read of size 8 at addr ffff888032a6e5f8 by task aoe_tx0/1418

CPU: 0 UID: 0 PID: 1418 Comm: aoe_tx0 Not tainted 6.13.0-rc2-syzkaller-00362-g2d8308bf5b67 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 uart_write_room+0x85e/0x940 drivers/tty/serial/serial_core.c:642
 tty_write_room+0x63/0x90 drivers/tty/tty_ioctl.c:69
 handle_tx+0x151/0x630 drivers/net/caif/caif_serial.c:226
 __netdev_start_xmit include/linux/netdevice.h:5002 [inline]
 netdev_start_xmit include/linux/netdevice.h:5011 [inline]
 xmit_one net/core/dev.c:3590 [inline]
 dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3606
 __dev_queue_xmit+0x7f0/0x43e0 net/core/dev.c:4434
 dev_queue_xmit include/linux/netdevice.h:3168 [inline]
 tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
 kthread+0x1e7/0x3c0 drivers/block/aoe/aoecmd.c:1237
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 7820:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 alloc_tty_struct+0x98/0x8d0 drivers/tty/tty_io.c:3116
 tty_init_dev.part.0+0x1e/0x660 drivers/tty/tty_io.c:1409
 tty_init_dev include/linux/err.h:67 [inline]
 tty_open_by_driver drivers/tty/tty_io.c:2082 [inline]
 tty_open+0xac1/0xf80 drivers/tty/tty_io.c:2129
 chrdev_open+0x237/0x6a0 fs/char_dev.c:414
 do_dentry_open+0xf59/0x1ea0 fs/open.c:945
 vfs_open+0x82/0x3f0 fs/open.c:1075
 do_open fs/namei.c:3828 [inline]
 path_openat+0x1e6a/0x2d60 fs/namei.c:3987
 do_filp_open+0x20c/0x470 fs/namei.c:4014
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1428
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1332:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x14f/0x4b0 mm/slub.c:4761
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:544
 insert_work+0x36/0x230 kernel/workqueue.c:2183
 __queue_work+0x97e/0x1080 kernel/workqueue.c:2339
 queue_work_on+0x11a/0x140 kernel/workqueue.c:2390
 kref_put include/linux/kref.h:65 [inline]
 tty_kref_put drivers/tty/tty_io.c:1566 [inline]
 tty_kref_put drivers/tty/tty_io.c:1563 [inline]
 release_tty+0x4de/0x5d0 drivers/tty/tty_io.c:1602
 tty_release_struct+0xb7/0xe0 drivers/tty/tty_io.c:1701
 tty_release+0xe25/0x1410 drivers/tty/tty_io.c:1861
 __fput+0x3f8/0xb60 fs/file_table.c:450
 task_work_run+0x14e/0x250 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xadd/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x24ed/0x26c0 kernel/signal.c:3017
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888032a6e000
 which belongs to the cache kmalloc-cg-2k of size 2048
The buggy address is located 1528 bytes inside of
 freed 2048-byte region [ffff888032a6e000, ffff888032a6e800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32a68
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88802308d481
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b050140 ffffea0000a8f600 dead000000000002
raw: 0000000000000000 0000000000080008 00000001f5000000 ffff88802308d481
head: 00fff00000000040 ffff88801b050140 ffffea0000a8f600 dead000000000002
head: 0000000000000000 0000000000080008 00000001f5000000 ffff88802308d481
head: 00fff00000000003 ffffea0000ca9a01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5943, tgid 5943 (syz-executor), ts 45865187412, free_ts 45833128412
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2269
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2589 [inline]
 new_slab+0x2c9/0x410 mm/slub.c:2642
 ___slab_alloc+0xd7d/0x17a0 mm/slub.c:3830
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 __do_kmalloc_node mm/slub.c:4297 [inline]
 __kmalloc_node_track_caller_noprof+0x2f1/0x510 mm/slub.c:4317
 kmemdup_noprof+0x29/0x60 mm/util.c:135
 kmemdup_noprof include/linux/fortify-string.h:753 [inline]
 __devinet_sysctl_register+0xbc/0x360 net/ipv4/devinet.c:2618
 devinet_sysctl_register net/ipv4/devinet.c:2670 [inline]
 devinet_sysctl_register+0x17b/0x200 net/ipv4/devinet.c:2660
 inetdev_init+0x2b8/0x5a0 net/ipv4/devinet.c:299
 inetdev_event+0xc61/0x18a0 net/ipv4/devinet.c:1598
 notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996
 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
 call_netdevice_notifiers net/core/dev.c:2048 [inline]
 register_netdevice+0x17a0/0x1e90 net/core/dev.c:10632
page last free pid 5941 tgid 5941 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0x1080 mm/page_alloc.c:2657
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_lru_noprof+0x226/0x3d0 mm/slub.c:4187
 __d_alloc+0x31/0xaa0 fs/dcache.c:1646
 d_alloc+0x4a/0x1e0 fs/dcache.c:1726
 d_alloc_parallel+0xe9/0x12b0 fs/dcache.c:2490
 __lookup_slow+0x194/0x460 fs/namei.c:1776
 lookup_one_len+0x181/0x1b0 fs/namei.c:2905
 start_creating.part.0+0x12f/0x3a0 fs/debugfs/inode.c:378
 start_creating fs/debugfs/inode.c:351 [inline]
 __debugfs_create_file+0xa5/0x660 fs/debugfs/inode.c:423
 debugfs_create_mode_unsafe fs/debugfs/file.c:559 [inline]
 debugfs_create_bool+0x70/0xa0 fs/debugfs/file.c:995
 nsim_bpf_init+0x15c/0x2e0 drivers/net/netdevsim/bpf.c:631
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:726 [inline]
 nsim_create+0x6f1/0xb20 drivers/net/netdevsim/netdev.c:793
 __nsim_dev_port_add+0x42c/0x7d0 drivers/net/netdevsim/dev.c:1393

Memory state around the buggy address:
 ffff888032a6e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888032a6e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888032a6e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff888032a6e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888032a6e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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