=========================[ 1051.967157][T19712] ================================================================== BUG: KASAN: slab-use-after-free in dvb_frontend_release+0x410/0x4e0 drivers/media/dvb-core/dvb_frontend.c:2916 Read of size 4 at addr ffff88802c3dc03c by task syz.3.4874/19712 CPU: 0 UID: 0 PID: 19712 Comm: syz.3.4874 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: 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_frontend_release+0x410/0x4e0 drivers/media/dvb-core/dvb_frontend.c:2916 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11c3/0x1310 kernel/signal.c:2809 arch_do_signal_or_restart+0xbc/0x850 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98 __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:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f234f5ace59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff19d5de88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fff19d5df70 RCX: 00007f234f5ace59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000fd053 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2dc20000 R11: 0000000000000246 R12: 00007fff19d5dfb0 R13: 00007f234f825fac R14: 00000000000fd4a2 R15: 00007f234f825fa0 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+0x3a6/0x690 mm/slub.c:5419 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [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:1418 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:709 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901 __driver_attach+0x34c/0x640 drivers/base/dd.c:1295 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383 bus_add_driver+0x348/0x670 drivers/base/bus.c:756 driver_register+0x23a/0x320 drivers/base/driver.c:249 vidtv_bridge_init+0x28/0x50 drivers/media/test-drivers/vidtv/vidtv_bridge.c:600 do_one_initcall+0x250/0x870 init/main.c:1392 do_initcall_level+0x104/0x190 init/main.c:1454 do_initcalls+0x59/0xa0 init/main.c:1470 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703 kernel_init+0x1d/0x1d0 init/main.c:1593 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 19712: 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:2689 [inline] slab_free mm/slub.c:6250 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6565 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_generic_release+0x123/0x1c0 drivers/media/dvb-core/dvbdev.c:169 dvb_frontend_release+0x138/0x4e0 drivers/media/dvb-core/dvb_frontend.c:2914 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11c3/0x1310 kernel/signal.c:2809 arch_do_signal_or_restart+0xbc/0x850 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98 __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:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802c3dc000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 60 bytes inside of freed 512-byte region [ffff88802c3dc000, ffff88802c3dc200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c3dc 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 ffff88801a010c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88801a010c80 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 1, tgid 1 (swapper/0), ts 14764761340, free_ts 14758812746 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7255 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __kmalloc_cache_noprof+0x44e/0x690 mm/slub.c:5414 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] device_private_init drivers/base/core.c:3536 [inline] device_add+0xbe/0xbb0 drivers/base/core.c:3587 i2c_new_client_device+0xa1f/0x1160 drivers/i2c/i2c-core-base.c:1018 dvb_module_probe+0x1c7/0x310 drivers/media/dvb-core/dvbdev.c:1039 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:1418 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:709 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901 __driver_attach+0x34c/0x640 drivers/base/dd.c:1295 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:1402 [inline] __free_frozen_pages+0xfa6/0x10f0 mm/page_alloc.c:2943 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+0x3a6/0x690 mm/slub.c:5419 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] i2c_new_client_device+0xd8/0x1160 drivers/i2c/i2c-core-base.c:966 dvb_module_probe+0x1c7/0x310 drivers/media/dvb-core/dvbdev.c:1039 vidtv_bridge_probe_demod drivers/media/test-drivers/vidtv/vidtv_bridge.c:354 [inline] vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:430 [inline] vidtv_bridge_probe+0x3de/0xf80 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510 platform_probe+0xf9/0x190 drivers/base/platform.c:1418 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:709 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901 __driver_attach+0x34c/0x640 drivers/base/dd.c:1295 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383 bus_add_driver+0x348/0x670 drivers/base/bus.c:756 driver_register+0x23a/0x320 drivers/base/driver.c:249 Memory state around the buggy address: ffff88802c3dbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802c3dbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88802c3dc000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802c3dc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802c3dc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================