==================================================================
BUG: KASAN: use-after-free in start_motor+0x31b/0x3f0 drivers/block/floppy.c:1906
Read of size 4 at addr ffff888017694100 by task kworker/u16:1/11

CPU: 1 PID: 11 Comm: kworker/u16:1 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Workqueue: floppy floppy_work_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
 __kasan_report mm/kasan/report.c:433 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
 start_motor+0x31b/0x3f0 drivers/block/floppy.c:1906
 floppy_ready+0x83/0x1850 drivers/block/floppy.c:1933
 recal_interrupt+0xd9/0x630 drivers/block/floppy.c:1698
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 27547:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 ____kasan_kmalloc mm/kasan/common.c:472 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:590 [inline]
 raw_cmd_copyin drivers/block/floppy.c:3093 [inline]
 raw_cmd_ioctl drivers/block/floppy.c:3160 [inline]
 fd_locked_ioctl+0x1110/0x2820 drivers/block/floppy.c:3528
 fd_ioctl drivers/block/floppy.c:3555 [inline]
 fd_compat_ioctl+0x891/0x1b60 drivers/block/floppy.c:3869
 compat_blkdev_ioctl+0x3b8/0x810 block/ioctl.c:674
 __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:972
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Freed by task 27547:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749
 slab_free mm/slub.c:3513 [inline]
 kfree+0xf6/0x560 mm/slub.c:4561
 raw_cmd_free+0x8a/0x1c0 drivers/block/floppy.c:3079
 raw_cmd_ioctl drivers/block/floppy.c:3180 [inline]
 fd_locked_ioctl+0x206a/0x2820 drivers/block/floppy.c:3528
 fd_ioctl drivers/block/floppy.c:3555 [inline]
 fd_compat_ioctl+0x891/0x1b60 drivers/block/floppy.c:3869
 compat_blkdev_ioctl+0x3b8/0x810 block/ioctl.c:674
 __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:972
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Last potentially related work creation:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348
 insert_work+0x48/0x370 kernel/workqueue.c:1354
 __queue_work+0x5ca/0xee0 kernel/workqueue.c:1520
 queue_work_on+0xee/0x110 kernel/workqueue.c:1547
 queue_work include/linux/workqueue.h:502 [inline]
 schedule_work include/linux/workqueue.h:563 [inline]
 nf_nat_masq_schedule.part.0+0x4e8/0x610 net/netfilter/nf_nat_masquerade.c:125
 nf_nat_masq_schedule net/netfilter/nf_nat_masquerade.c:104 [inline]
 masq_inet6_event net/netfilter/nf_nat_masquerade.c:290 [inline]
 masq_inet6_event+0x1e4/0x230 net/netfilter/nf_nat_masquerade.c:274
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 atomic_notifier_call_chain+0x70/0x180 kernel/notifier.c:198
 addrconf_ifdown.isra.0+0xa58/0x1630 net/ipv6/addrconf.c:3841
 addrconf_notify+0xeb/0x1bb0 net/ipv6/addrconf.c:3651
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2002
 call_netdevice_notifiers_extack net/core/dev.c:2014 [inline]
 call_netdevice_notifiers net/core/dev.c:2028 [inline]
 __dev_notify_flags+0x1da/0x2b0 net/core/dev.c:8833
 dev_change_flags+0x112/0x170 net/core/dev.c:8869
 do_setlink+0x96d/0x3970 net/core/rtnetlink.c:2719
 rtnl_group_changelink net/core/rtnetlink.c:3242 [inline]
 __rtnl_newlink+0xc06/0x1750 net/core/rtnetlink.c:3396
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3506
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348
 insert_work+0x48/0x370 kernel/workqueue.c:1354
 __queue_work+0x5ca/0xee0 kernel/workqueue.c:1520
 queue_work_on+0xee/0x110 kernel/workqueue.c:1547
 queue_work include/linux/workqueue.h:502 [inline]
 schedule_work include/linux/workqueue.h:563 [inline]
 nf_nat_masq_schedule.part.0+0x4e8/0x610 net/netfilter/nf_nat_masquerade.c:125
 nf_nat_masq_schedule net/netfilter/nf_nat_masquerade.c:104 [inline]
 masq_device_event+0xf1/0x120 net/netfilter/nf_nat_masquerade.c:157
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2002
 call_netdevice_notifiers_extack net/core/dev.c:2014 [inline]
 call_netdevice_notifiers net/core/dev.c:2028 [inline]
 __dev_notify_flags+0x1da/0x2b0 net/core/dev.c:8833
 dev_change_flags+0x112/0x170 net/core/dev.c:8869
 do_setlink+0x96d/0x3970 net/core/rtnetlink.c:2719
 rtnl_group_changelink net/core/rtnetlink.c:3242 [inline]
 __rtnl_newlink+0xc06/0x1750 net/core/rtnetlink.c:3396
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3506
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2491
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x86d/0xda0 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

The buggy address belongs to the object at ffff888017694100
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes inside of
 128-byte region [ffff888017694100, ffff888017694180)
The buggy address belongs to the page:
page:ffffea00005da500 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888017694c00 pfn:0x17694
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000001 ffff888010c428c0
raw: ffff888017694c00 000000008010000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 3710, ts 201773631874, free_ts 72935810245
 prep_new_page mm/page_alloc.c:2418 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191
 alloc_slab_page mm/slub.c:1793 [inline]
 allocate_slab mm/slub.c:1930 [inline]
 new_slab+0x32d/0x4a0 mm/slub.c:1993
 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
 slab_alloc_node mm/slub.c:3200 [inline]
 slab_alloc mm/slub.c:3242 [inline]
 kmem_cache_alloc_trace+0x289/0x2c0 mm/slub.c:3259
 kmalloc include/linux/slab.h:590 [inline]
 __hw_addr_create net/core/dev_addr_lists.c:29 [inline]
 __hw_addr_add_ex+0x281/0x940 net/core/dev_addr_lists.c:93
 __dev_mc_add net/core/dev_addr_lists.c:832 [inline]
 dev_mc_add+0xbd/0x110 net/core/dev_addr_lists.c:850
 ip_mc_filter_add net/ipv4/igmp.c:1149 [inline]
 igmp_group_added+0x765/0x930 net/ipv4/igmp.c:1335
 ____ip_mc_inc_group+0x5ad/0xc70 net/ipv4/igmp.c:1468
 __ip_mc_inc_group net/ipv4/igmp.c:1477 [inline]
 ip_mc_inc_group net/ipv4/igmp.c:1483 [inline]
 ip_mc_up+0x14b/0x360 net/ipv4/igmp.c:1782
 inetdev_event+0x2e8/0x15d0 net/ipv4/devinet.c:1575
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2002
 call_netdevice_notifiers_extack net/core/dev.c:2014 [inline]
 call_netdevice_notifiers net/core/dev.c:2028 [inline]
 __dev_notify_flags+0x110/0x2b0 net/core/dev.c:8831
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1338 [inline]
 free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3309 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3388
 __vunmap+0x781/0xb70 mm/vmalloc.c:2632
 free_work+0x58/0x70 mm/vmalloc.c:95
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff888017694000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888017694080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888017694100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888017694180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888017694200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================