==================================================================
BUG: KASAN: use-after-free in sixpack_close+0x236/0x270 drivers/net/hamradio/6pack.c:678
Read of size 8 at addr ffff88800993ac90 by task syz-executor.3/4833

CPU: 0 PID: 4833 Comm: syz-executor.3 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
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
 sixpack_close+0x236/0x270 drivers/net/hamradio/6pack.c:678
 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:474
 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:629
 tty_ldisc_release+0xe3/0x2a0 drivers/tty/tty_ldisc.c:803
 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1706
 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1878
 __fput+0x286/0x9f0 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf6e73549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000ff9e69c0 EFLAGS: 00000282 ORIG_RAX: 0000000000000006
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 00000000f6fa9000 RDI: 000000000004fa17
RBP: 00000000f6fd0760 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 4834:
 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_node include/linux/slab.h:613 [inline]
 kvmalloc_node+0x61/0x120 mm/util.c:587
 kvmalloc include/linux/slab.h:741 [inline]
 kvzalloc include/linux/slab.h:749 [inline]
 alloc_netdev_mqs+0x98/0xec0 net/core/dev.c:10828
 sixpack_open+0xfa/0xa50 drivers/net/hamradio/6pack.c:558
 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:449
 tty_set_ldisc+0x2f1/0x680 drivers/tty/tty_ldisc.c:579
 tiocsetd drivers/tty/tty_io.c:2455 [inline]
 tty_ioctl+0xae0/0x1670 drivers/tty/tty_io.c:2741
 tty_compat_ioctl+0x295/0x410 drivers/tty/tty_io.c:2955
 __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 4833:
 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
 kvfree+0x42/0x50 mm/util.c:620
 device_release+0x9f/0x240 drivers/base/core.c:2230
 kobject_cleanup lib/kobject.c:705 [inline]
 kobject_release lib/kobject.c:736 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1c8/0x540 lib/kobject.c:753
 netdev_run_todo+0x75a/0xa80 net/core/dev.c:10638
 sixpack_close+0x184/0x270 drivers/net/hamradio/6pack.c:675
 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:474
 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:629
 tty_ldisc_release+0xe3/0x2a0 drivers/tty/tty_ldisc.c:803
 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1706
 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1878
 __fput+0x286/0x9f0 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181
 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 ffff88800993a000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 3216 bytes inside of
 4096-byte region [ffff88800993a000, ffff88800993b000)
The buggy address belongs to the page:
page:ffffea0000264e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9938
head:ffffea0000264e00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888015ec3dc1
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c4c140
raw: 0000000000000000 0000000000040004 00000001ffffffff ffff888015ec3dc1
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3131, ts 263871826929, free_ts 232319841663
 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]
 __kmalloc_node+0x2cb/0x390 mm/slub.c:4467
 kmalloc_node include/linux/slab.h:613 [inline]
 kvmalloc_node+0x61/0x120 mm/util.c:587
 kvmalloc include/linux/slab.h:741 [inline]
 seq_buf_alloc fs/seq_file.c:38 [inline]
 seq_read_iter+0x7e7/0x1240 fs/seq_file.c:210
 kernfs_fop_read_iter+0x44f/0x5f0 fs/kernfs/file.c:241
 call_read_iter include/linux/fs.h:2156 [inline]
 new_sync_read+0x421/0x6e0 fs/read_write.c:400
 vfs_read+0x35c/0x600 fs/read_write.c:481
 ksys_read+0x12d/0x250 fs/read_write.c:619
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
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
 __put_single_page mm/swap.c:99 [inline]
 __put_page+0x13d/0x470 mm/swap.c:130
 folio_put include/linux/mm.h:1237 [inline]
 put_page include/linux/mm.h:1255 [inline]
 unmap_and_move mm/migrate.c:1237 [inline]
 migrate_pages+0x2737/0x3810 mm/migrate.c:1481
 compact_zone+0x1abb/0x3860 mm/compaction.c:2399
 proactive_compact_node+0x103/0x1c0 mm/compaction.c:2653
 kcompactd+0x5b4/0xf30 mm/compaction.c:2963
 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:
 ffff88800993ab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88800993ac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88800993ac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88800993ad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88800993ad80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	03 74 c0 01          	add    0x1(%rax,%rax,8),%esi
   4:	10 05 03 74 b8 01    	adc    %al,0x1b87403(%rip)        # 0x1b8740d
   a:	10 06                	adc    %al,(%rsi)
   c:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
  10:	10 07                	adc    %al,(%rdi)
  12:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
  16:	10 08                	adc    %cl,(%rax)
  18:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1c:	00 00                	add    %al,(%rax)
  1e:	00 00                	add    %al,(%rax)
  20:	00 51 52             	add    %dl,0x52(%rcx)
  23:	55                   	push   %rbp
  24:	89 e5                	mov    %esp,%ebp
  26:	0f 34                	sysenter
  28:	cd 80                	int    $0x80
* 2a:	5d                   	pop    %rbp <-- trapping instruction
  2b:	5a                   	pop    %rdx
  2c:	59                   	pop    %rcx
  2d:	c3                   	retq
  2e:	90                   	nop
  2f:	90                   	nop
  30:	90                   	nop
  31:	90                   	nop
  32:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  39:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi