==================================================================
BUG: KASAN: slab-use-after-free in dvb_device_open+0xc4/0x360 drivers/media/dvb-core/dvbdev.c:99
Read of size 8 at addr ffff88802c7dd018 by task syz.0.19/5837

CPU: 1 UID: 0 PID: 5837 Comm: syz.0.19 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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+0xc4/0x360 drivers/media/dvb-core/dvbdev.c:99
 chrdev_open+0x4d0/0x5f0 fs/char_dev.c:411
 do_dentry_open+0x83d/0x13e0 fs/open.c:947
 vfs_open+0x3b/0x350 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e24/0x37e0 fs/namei.c:4859
 do_file_open+0x23e/0x4a0 fs/namei.c:4888
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffb40f4d68e
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:00007ffefbd505b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055558fdc1500 RCX: 00007ffb40f4d68e
RDX: 0000000000000002 RSI: 00007ffefbd50690 RDI: ffffffffffffff9c
RBP: 00007ffefbd50690 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007ffb41205fac R14: 00007ffb41205fa0 R15: 00007ffb41205fa0
 </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:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3d0/0x6d0 mm/slub.c:5510
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1287 [inline]
 dvb_register_device+0x2fd/0x21e0 drivers/media/dvb-core/dvbdev.c:472
 dvb_register_frontend+0x631/0x920 drivers/media/dvb-core/dvb_frontend.c:3051
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline]
 vidtv_bridge_probe+0x9aa/0xf80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0xf9/0x190 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:706
 __driver_probe_device+0x1e2/0x350 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x33c/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x348/0x670 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:1347
 do_initcall_level+0x104/0x190 init/main.c:1409
 do_initcalls+0x59/0xa0 init/main.c:1425
 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1658
 kernel_init+0x1d/0x1d0 init/main.c:1548
 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 5836:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2699 [inline]
 slab_free mm/slub.c:6400 [inline]
 kfree+0x1c5/0x6c0 mm/slub.c:6715
 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+0x2d6/0x360 drivers/media/dvb-core/dvbdev.c:113
 chrdev_open+0x4d0/0x5f0 fs/char_dev.c:411
 do_dentry_open+0x83d/0x13e0 fs/open.c:947
 vfs_open+0x3b/0x350 fs/open.c:1052
 do_open fs/namei.c:4700 [inline]
 path_openat+0x2e24/0x37e0 fs/namei.c:4859
 do_file_open+0x23e/0x4a0 fs/namei.c:4888
 do_sys_openat2+0x115/0x200 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802c7dd000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff88802c7dd000, ffff88802c7dd200)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c7dc
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813fe30c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813fe30c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1255, tgid 1255 (kworker/0:3), ts 14448062089, free_ts 14440335109
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x265c/0x26e0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3288 [inline]
 allocate_slab+0x76/0x5d0 mm/slub.c:3406
 new_slab mm/slub.c:3452 [inline]
 refill_objects+0x2d9/0x350 mm/slub.c:7333
 refill_sheaf mm/slub.c:2826 [inline]
 __pcs_replace_empty_main+0x331/0x690 mm/slub.c:4698
 alloc_from_pcs mm/slub.c:4796 [inline]
 slab_alloc_node mm/slub.c:4929 [inline]
 __kmalloc_cache_noprof+0x482/0x6d0 mm/slub.c:5506
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1287 [inline]
 device_private_init drivers/base/core.c:3602 [inline]
 device_add+0xbe/0xb90 drivers/base/core.c:3653
 cdev_device_add+0x1d6/0x390 fs/char_dev.c:553
 evdev_connect+0x354/0x400 drivers/input/evdev.c:1383
 input_attach_handler drivers/input/input.c:1011 [inline]
 input_register_device+0xcd0/0x1130 drivers/input/input.c:2395
 atkbd_connect+0x6f9/0x9f0 drivers/input/keyboard/atkbd.c:1323
 serio_connect_driver drivers/input/serio/serio.c:44 [inline]
 serio_driver_probe+0x7f/0xa0 drivers/input/serio/serio.c:748
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:706
 __driver_probe_device+0x1e2/0x350 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x10af/0x1190 mm/page_alloc.c:2950
 stack_depot_save_flags+0x40e/0x810 lib/stackdepot.c:735
 kasan_save_stack mm/kasan/common.c:58 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3d0/0x6d0 mm/slub.c:5510
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1287 [inline]
 dvb_module_probe+0x64/0x310 drivers/media/dvb-core/dvbdev.c:1027
 vidtv_bridge_probe_tuner drivers/media/test-drivers/vidtv/vidtv_bridge.c:407 [inline]
 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:434 [inline]
 vidtv_bridge_probe+0x93b/0xf80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510
 platform_probe+0xf9/0x190 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:706
 __driver_probe_device+0x1e2/0x350 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x33c/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x348/0x670 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

Memory state around the buggy address:
 ffff88802c7dcf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802c7dcf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802c7dd000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802c7dd080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802c7dd100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================