================================================================== BUG: KASAN: use-after-free in dvb_frontend_release+0x384/0x400 drivers/media/dvb-core/dvb_frontend.c:2900 Read of size 4 at addr ffff0000d31ec83c by task syz.1.32/4564 CPU: 0 PID: 4564 Comm: syz.1.32 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 __asan_report_load4_noabort+0x2c/0x38 mm/kasan/report_generic.c:350 dvb_frontend_release+0x384/0x400 drivers/media/dvb-core/dvb_frontend.c:2900 __fput+0x1bc/0x7b8 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1ec/0x278 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x550/0x19b0 kernel/exit.c:881 do_group_exit+0x194/0x22c kernel/exit.c:1023 get_signal+0x11cc/0x1304 kernel/signal.c:2871 do_signal arch/arm64/kernel/signal.c:1095 [inline] do_notify_resume+0x33c/0x2aa4 arch/arm64/kernel/signal.c:1148 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 1: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] dvb_register_device+0x1a0/0x17a8 drivers/media/dvb-core/dvbdev.c:478 dvb_register_frontend+0x4c0/0x720 drivers/media/dvb-core/dvb_frontend.c:3035 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:436 [inline] vidtv_bridge_probe+0x9ac/0xe34 drivers/media/test-drivers/vidtv/vidtv_bridge.c:508 platform_probe+0x13c/0x1b4 drivers/base/platform.c:1400 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x39c/0xacc drivers/base/dd.c:639 __driver_probe_device+0x180/0x310 drivers/base/dd.c:785 driver_probe_device+0x78/0x324 drivers/base/dd.c:815 __driver_attach+0x3bc/0x60c drivers/base/dd.c:1201 bus_for_each_dev+0x148/0x1d0 drivers/base/bus.c:303 driver_attach+0x4c/0x5c drivers/base/dd.c:1218 bus_add_driver+0x2d8/0x554 drivers/base/bus.c:620 driver_register+0x200/0x378 drivers/base/driver.c:246 __platform_driver_register+0x6c/0x80 drivers/base/platform.c:867 vidtv_bridge_init+0x4c/0x8c drivers/media/test-drivers/vidtv/vidtv_bridge.c:600 do_one_initcall+0x278/0x9e0 init/main.c:1310 do_initcall_level+0x154/0x214 init/main.c:1383 do_initcalls+0x58/0xac init/main.c:1399 do_basic_setup+0x8c/0xa0 init/main.c:1418 kernel_init_freeable+0x35c/0x4f0 init/main.c:1638 kernel_init+0x24/0x1d8 init/main.c:1526 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Freed by task 4564: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xbc/0x218 mm/slub.c:3700 kfree+0xd0/0x1a8 mm/slab_common.c:988 dvb_free_device drivers/media/dvb-core/dvbdev.c:625 [inline] kref_put include/linux/kref.h:65 [inline] dvb_device_put drivers/media/dvb-core/dvbdev.c:640 [inline] dvb_generic_release+0x128/0x1e0 drivers/media/dvb-core/dvbdev.c:173 dvb_frontend_release+0x114/0x400 drivers/media/dvb-core/dvb_frontend.c:2898 __fput+0x1bc/0x7b8 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1ec/0x278 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x550/0x19b0 kernel/exit.c:881 do_group_exit+0x194/0x22c kernel/exit.c:1023 get_signal+0x11cc/0x1304 kernel/signal.c:2871 do_signal arch/arm64/kernel/signal.c:1095 [inline] do_notify_resume+0x33c/0x2aa4 arch/arm64/kernel/signal.c:1148 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the object at ffff0000d31ec800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 60 bytes inside of 256-byte region [ffff0000d31ec800, ffff0000d31ec900) The buggy address belongs to the physical page: page:000000007157c12c refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000d31ec600 pfn:0x1131ec head:000000007157c12c order:1 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 fffffc00034e9088 fffffc00034c7b88 ffff0000c0002480 raw: ffff0000d31ec600 0000000000100009 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d31ec700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000d31ec780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000d31ec800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d31ec880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d31ec900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================