===================
==================================================================
BUG: KASAN: slab-use-after-free in dvb_device_open+0xc4/0x340 drivers/media/dvb-core/dvbdev.c:99
Read of size 8 at addr ffff88802c34d418 by task syz.0.19/5888

CPU: 0 UID: 0 PID: 5888 Comm: syz.0.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 dvb_device_open+0xc4/0x340 drivers/media/dvb-core/dvbdev.c:99
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce9f95e98e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffce7d45ad8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055558b9a9500 RCX: 00007fce9f95e98e
RDX: 0000000000000002 RSI: 00007ffce7d45bb0 RDI: ffffffffffffff9c
RBP: 00007ffce7d45bb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007fce9fc25fac R14: 00007fce9fc25fa0 R15: 00007fce9fc25fa0
 </TASK>

Allocated by task 1:
 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:409 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 dvb_register_device+0x309/0x1dd0 drivers/media/dvb-core/dvbdev.c:472
 dvb_register_frontend+0x603/0x900 drivers/media/dvb-core/dvb_frontend.c:3074
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline]
 vidtv_bridge_probe+0x9d5/0xf60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0xf9/0x190 drivers/base/platform.c:1507
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x339/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x345/0x670 drivers/base/bus.c:763
 driver_register+0x23a/0x320 drivers/base/driver.c:174
 vidtv_bridge_init+0x3d/0x60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602
 do_one_initcall+0x250/0x870 init/main.c:1362
 do_initcall_level+0x10a/0x1a0 init/main.c:1424
 do_initcalls+0x59/0xa0 init/main.c:1440
 kernel_init_freeable+0x29d/0x3e0 init/main.c:1675
 kernel_init+0x22/0x1d0 init/main.c:1565
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5886:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6508 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6801
 dvb_free_device drivers/media/dvb-core/dvbdev.c:616 [inline]
 kref_put include/linux/kref.h:65 [inline]
 dvb_device_put drivers/media/dvb-core/dvbdev.c:629 [inline]
 dvb_device_open+0x2b8/0x340 drivers/media/dvb-core/dvbdev.c:113
 chrdev_open+0x4d9/0x600 fs/char_dev.c:411
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802c34d400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 24 bytes inside of
 freed 256-byte region [ffff88802c34d400, ffff88802c34d500)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c34c
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 ffff88801b041b40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b041b40 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 15737211392
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7417
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x39b/0x600 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 bus_add_driver+0x162/0x670 drivers/base/bus.c:747
 driver_register+0x23a/0x320 drivers/base/driver.c:174
 usb_register_driver+0x1e4/0x390 drivers/usb/core/driver.c:1082
 do_one_initcall+0x250/0x870 init/main.c:1362
 do_initcall_level+0x10a/0x1a0 init/main.c:1424
 do_initcalls+0x59/0xa0 init/main.c:1440
 kernel_init_freeable+0x29d/0x3e0 init/main.c:1675
 kernel_init+0x22/0x1d0 init/main.c:1565
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802c34d300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802c34d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802c34d400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802c34d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802c34d500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================