================================================================== BUG: KASAN: slab-use-after-free in dvb_frontend_release+0x4f3/0x5d0 drivers/media/dvb-core/dvb_frontend.c:2916 Read of size 4 at addr ffff88802cf5d63c by task syz.0.1927/12697 CPU: 2 UID: 0 PID: 12697 Comm: syz.0.1927 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 dvb_frontend_release+0x4f3/0x5d0 drivers/media/dvb-core/dvb_frontend.c:2916 __fput+0x3ff/0xb50 fs/file_table.c:510 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 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+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f15fd99cdd9 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:00007ffde73fa3b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffde73fa4a0 RCX: 00007f15fd99cdd9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000000372de R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b32120000 R11: 0000000000000246 R12: 00007ffde73fa4e0 R13: 00007f15fdc15fac R14: 0000000000037341 R15: 00007f15fdc15fa0 Allocated by task 1: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] dvb_register_device+0x1d6/0x1e20 drivers/media/dvb-core/dvbdev.c:472 dvb_register_frontend+0x552/0x820 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+0x44b/0xa30 drivers/media/test-drivers/vidtv/vidtv_bridge.c:510 platform_probe+0x106/0x1d0 drivers/base/platform.c:1418 call_driver_probe drivers/base/dd.c:631 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:709 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:901 __driver_attach+0x21f/0x5d0 drivers/base/dd.c:1295 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383 bus_add_driver+0x305/0x5b0 drivers/base/bus.c:756 driver_register+0x1e2/0x360 drivers/base/driver.c:249 vidtv_bridge_init+0x38/0x70 drivers/media/test-drivers/vidtv/vidtv_bridge.c:600 do_one_initcall+0x121/0x750 init/main.c:1392 do_initcall_level init/main.c:1454 [inline] do_initcalls init/main.c:1470 [inline] do_basic_setup init/main.c:1490 [inline] kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703 kernel_init+0x1f/0x1e0 init/main.c:1593 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 12697: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/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+0x223/0x6c0 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.part.0+0x57/0x90 drivers/media/dvb-core/dvbdev.c:629 dvb_device_put drivers/media/dvb-core/dvbdev.c:171 [inline] dvb_generic_release+0xe2/0x160 drivers/media/dvb-core/dvbdev.c:169 dvb_frontend_release+0x13d/0x5d0 drivers/media/dvb-core/dvb_frontend.c:2914 __fput+0x3ff/0xb50 fs/file_table.c:510 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 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+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802cf5d600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 60 bytes inside of freed 256-byte region [ffff88802cf5d600, ffff88802cf5d700) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2cf5c 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 ffff88801b842b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842b40 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 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 0xd2000(__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 16181751002, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7255 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5414 kmalloc_noprof include/linux/slab.h:950 [inline] usb_string+0x10f/0x570 drivers/usb/core/message.c:1038 usb_cache_string+0x7c/0x100 drivers/usb/core/message.c:1090 usb_enumerate_device drivers/usb/core/hub.c:2538 [inline] usb_new_device+0x1d1/0x7d0 drivers/usb/core/hub.c:2665 register_root_hub+0x4e6/0x639 drivers/usb/core/hcd.c:990 usb_add_hcd.cold+0xccd/0x1158 drivers/usb/core/hcd.c:2987 vhci_hcd_probe+0x1c2/0x4e0 drivers/usb/usbip/vhci_hcd.c:1401 platform_probe+0x106/0x1d0 drivers/base/platform.c:1418 call_driver_probe drivers/base/dd.c:631 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:709 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871 page_owner free stack trace missing Memory state around the buggy address: ffff88802cf5d500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802cf5d580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802cf5d600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802cf5d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802cf5d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================