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BUG: KASAN: slab-use-after-free in dvb_frontend_release+0x4f3/0x5d0 drivers/media/dvb-core/dvb_frontend.c:2939
Read of size 4 at addr ffff88802fdba63c by task syz.0.95/6256

CPU: 3 UID: 0 PID: 6256 Comm: syz.0.95 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 dvb_frontend_release+0x4f3/0x5d0 drivers/media/dvb-core/dvb_frontend.c:2939
 __fput+0x3fb/0xb50 fs/file_table.c:512
 fput_close_sync+0x118/0x250 fs/file_table.c:618
 filp_close_sync+0x75/0xa0 fs/open.c:1573
 close_files fs/file.c:572 [inline]
 put_files_struct fs/file.c:584 [inline]
 put_files_struct+0x1f7/0x390 fs/file.c:581
 switch_files_struct fs/file.c:598 [inline]
 exit_files+0x85/0xb0 fs/file.c:604
 do_exit+0x896/0x2a00 kernel/exit.c:977
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1123
 get_signal+0x1f58/0x22e0 kernel/signal.c:3113
 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x139/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb96f96034e
Code: Unable to access opcode bytes at 0x7fb96f960324.
RSP: 002b:00007fb970938b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: 0000000000000003 RBX: 00007fb9709396c0 RCX: 00007fb96f96034e
RDX: 0000000000000000 RSI: 00007fb970938c00 RDI: ffffffffffffff9c
RBP: 00007fb970938c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007fb96fc26038 R14: 00007fb96fc25fa0 R15: 00007fffe6f78498
 </TASK>

Allocated by task 1:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5680
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 dvb_register_device+0x1d6/0x1e20 drivers/media/dvb-core/dvbdev.c:472
 dvb_register_frontend+0x552/0x820 drivers/media/dvb-core/dvb_frontend.c:3074
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:507 [inline]
 vidtv_bridge_probe+0x447/0xa50 drivers/media/test-drivers/vidtv/vidtv_bridge.c:580
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1508
 call_driver_probe drivers/base/dd.c:629 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:707
 __driver_probe_device+0x210/0x460 drivers/base/dd.c:869
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:899
 __driver_attach+0x231/0x5b0 drivers/base/dd.c:1300
 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
 bus_add_driver+0x4bf/0x620 drivers/base/bus.c:782
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 vidtv_bridge_init+0x52/0x80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:675
 do_one_initcall+0x11c/0x6f0 init/main.c:1419
 do_initcall_level init/main.c:1481 [inline]
 do_initcalls init/main.c:1497 [inline]
 do_basic_setup init/main.c:1517 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1732
 kernel_init+0x21/0x1e0 init/main.c:1622
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 6256:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6923
 dvb_free_device drivers/media/dvb-core/dvbdev.c:616 [inline]
 kref_put include/linux/kref.h:65 [inline]
 dvb_device_put.part.0+0x57/0x90 drivers/media/dvb-core/dvbdev.c:629
 dvb_device_put drivers/media/dvb-core/dvbdev.c:171 [inline]
 dvb_generic_release+0xe2/0x160 drivers/media/dvb-core/dvbdev.c:169
 dvb_frontend_release+0x13d/0x5d0 drivers/media/dvb-core/dvb_frontend.c:2937
 __fput+0x3fb/0xb50 fs/file_table.c:512
 fput_close_sync+0x118/0x250 fs/file_table.c:618
 filp_close_sync+0x75/0xa0 fs/open.c:1573
 close_files fs/file.c:572 [inline]
 put_files_struct fs/file.c:584 [inline]
 put_files_struct+0x1f7/0x390 fs/file.c:581
 switch_files_struct fs/file.c:598 [inline]
 exit_files+0x85/0xb0 fs/file.c:604
 do_exit+0x896/0x2a00 kernel/exit.c:977
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1123
 get_signal+0x1f58/0x22e0 kernel/signal.c:3113
 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x139/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802fdba600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 60 bytes inside of
 freed 256-byte region [ffff88802fdba600, ffff88802fdba700)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2fdba
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801d442b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d442b40 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 8928460494
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1856
 prep_new_page mm/page_alloc.c:1864 [inline]
 get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3935
 __alloc_frozen_pages_noprof+0x2bd/0x3280 mm/page_alloc.c:5444
 alloc_slab_page mm/slub.c:3384 [inline]
 allocate_slab mm/slub.c:3499 [inline]
 new_slab+0xb1/0x6d0 mm/slub.c:3550
 refill_objects+0xe3/0x410 mm/slub.c:7539
 refill_sheaf mm/slub.c:2917 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811
 alloc_from_pcs mm/slub.c:4887 [inline]
 slab_alloc_node mm/slub.c:5021 [inline]
 __kmalloc_cache_noprof+0x4ef/0x6d0 mm/slub.c:5676
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 bus_add_driver+0xdc/0x620 drivers/base/bus.c:766
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 do_one_initcall+0x11c/0x6f0 init/main.c:1419
 do_initcall_level init/main.c:1481 [inline]
 do_initcalls init/main.c:1497 [inline]
 do_basic_setup init/main.c:1517 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1732
 kernel_init+0x21/0x1e0 init/main.c:1622
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802fdba500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802fdba580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802fdba600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88802fdba680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802fdba700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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