================================================================== BUG: KASAN: use-after-free in dvb_frontend_release+0x3f8/0x4a0 drivers/media/dvb-core/dvb_frontend.c:2903 Read of size 4 at addr ffff88814b67b63c by task syz.5.350/5736 CPU: 1 PID: 5736 Comm: syz.5.350 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 dvb_frontend_release+0x3f8/0x4a0 drivers/media/dvb-core/dvb_frontend.c:2903 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x123e/0x12e0 kernel/signal.c:2673 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd062896e59 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:00007ffefd55d598 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffefd55d680 RCX: 00007fd062896e59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000388e3 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2e320000 R11: 0000000000000246 R12: 00007ffefd55d6c0 R13: 00007fd062b1efac R14: 0000000000038952 R15: 00007fd062b1efa0 Allocated by task 1: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] dvb_register_device+0x300/0x1dc0 drivers/media/dvb-core/dvbdev.c:488 dvb_register_frontend+0x629/0x900 drivers/media/dvb-core/dvb_frontend.c:3034 vidtv_bridge_dvb_init drivers/media/test-drivers/vidtv/vidtv_bridge.c:438 [inline] vidtv_bridge_probe+0x9c1/0xf30 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x276/0xc70 drivers/base/dd.c:595 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805 __driver_attach+0x45d/0x660 drivers/base/dd.c:1184 bus_for_each_dev+0x182/0x1f0 drivers/base/bus.c:303 bus_add_driver+0x324/0x5d0 drivers/base/bus.c:620 driver_register+0x32d/0x430 drivers/base/driver.c:240 vidtv_bridge_init+0x39/0x70 drivers/media/test-drivers/vidtv/vidtv_bridge.c:602 do_one_initcall+0x272/0x730 init/main.c:1315 do_initcall_level+0x13d/0x1f0 init/main.c:1388 do_initcalls+0x4b/0x90 init/main.c:1404 kernel_init_freeable+0x3d5/0x560 init/main.c:1628 kernel_init+0x19/0x1b0 init/main.c:1519 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 5736: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 dvb_free_device drivers/media/dvb-core/dvbdev.c:635 [inline] kref_put include/linux/kref.h:65 [inline] dvb_device_put drivers/media/dvb-core/dvbdev.c:650 [inline] dvb_generic_release+0x11c/0x1b0 drivers/media/dvb-core/dvbdev.c:183 dvb_frontend_release+0x134/0x4a0 drivers/media/dvb-core/dvb_frontend.c:2901 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x123e/0x12e0 kernel/signal.c:2673 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88814b67b600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 60 bytes inside of 256-byte region [ffff88814b67b600, ffff88814b67b700) The buggy address belongs to the page: page:ffffea00052d9e80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14b67a head:ffffea00052d9e80 order:1 compound_mapcount:0 flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000010200 dead000000000100 dead000000000122 ffff888016c41b40 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 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, ts 19311087616, free_ts 0 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node+0x142/0x3a0 mm/slub.c:4456 kmalloc_node include/linux/slab.h:630 [inline] kvmalloc_node+0x84/0x130 mm/util.c:619 kvmalloc include/linux/mm.h:816 [inline] kvzalloc include/linux/mm.h:824 [inline] v4l2_ctrl_new+0x70f/0x1310 drivers/media/v4l2-core/v4l2-ctrls-core.c:1306 v4l2_ctrl_new_std+0x247/0x300 drivers/media/v4l2-core/v4l2-ctrls-core.c:1429 handler_new_ref+0x14f/0x8d0 drivers/media/v4l2-core/v4l2-ctrls-core.c:1098 v4l2_ctrl_add_handler+0x197/0x280 drivers/media/v4l2-core/v4l2-ctrls-core.c:1573 vivid_create_controls+0x26e6/0x3380 drivers/media/test-drivers/vivid/vivid-ctrls.c:1900 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1860 [inline] vivid_probe+0x39ff/0x6240 drivers/media/test-drivers/vivid/vivid-core.c:2031 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x276/0xc70 drivers/base/dd.c:595 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775 page_owner free stack trace missing Memory state around the buggy address: ffff88814b67b500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88814b67b580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88814b67b600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88814b67b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88814b67b700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================