================================================================== BUG: KASAN: slab-use-after-free in dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99 Read of size 8 at addr ffff888021487618 by task syz.0.32055/9258 CPU: 3 UID: 0 PID: 9258 Comm: syz.0.32055 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+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99 chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6d8/0x1660 fs/open.c:949 vfs_open+0x82/0x3f0 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4830 do_file_open+0x20e/0x430 fs/namei.c:4859 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_compat_sys_openat fs/open.c:1434 [inline] __se_compat_sys_openat fs/open.c:1432 [inline] __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1432 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] do_int80_emulation+0x141/0x6b0 arch/x86/entry/syscall_32.c:172 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 RIP: 0023:0xf717572b Code: 57 56 53 8b 44 24 14 f6 00 08 75 23 8b 44 24 18 8b 5c 24 1c 8b 4c 24 20 8b 54 24 24 8b 74 24 28 8b 7c 24 2c 8b 6c 24 30 cd 80 <5b> 5e 5f 5d c3 5b 5e 5f 5d e9 f7 a1 ff ff 66 90 66 90 66 90 90 53 RSP: 002b:00000000f543603c EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000f5436100 RDX: 0000000000040002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 2484: 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 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5219 [inline] __kvmalloc_node_noprof+0x360/0xa00 mm/slub.c:6711 v4l2_ctrl_new+0x4a6/0x23a0 drivers/media/v4l2-core/v4l2-ctrls-core.c:2140 v4l2_ctrl_new_std+0x1bb/0x290 drivers/media/v4l2-core/v4l2-ctrls-core.c:2294 cx25840_probe.cold+0x90d/0xf2c drivers/media/i2c/cx25840/cx25840-core.c:3892 i2c_device_probe+0x658/0xd10 drivers/i2c/i2c-core-base.c:592 call_driver_probe drivers/base/dd.c:583 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:661 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:803 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:833 __device_attach_driver+0x1ff/0x3e0 drivers/base/dd.c:961 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1033 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1088 bus_probe_device+0x64/0x160 drivers/base/bus.c:574 device_add+0x11d9/0x1950 drivers/base/core.c:3689 i2c_new_client_device+0x660/0xd30 drivers/i2c/i2c-core-base.c:1019 v4l2_i2c_new_subdev_board+0xb6/0x2b0 drivers/media/v4l2-core/v4l2-i2c.c:81 v4l2_i2c_new_subdev+0x13e/0x190 drivers/media/v4l2-core/v4l2-i2c.c:136 pvr2_hdw_load_subdev drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2022 [inline] pvr2_hdw_load_modules drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2074 [inline] pvr2_hdw_setup_low drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2155 [inline] pvr2_hdw_setup drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2261 [inline] pvr2_hdw_initialize+0x2158/0x3710 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2338 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:111 [inline] pvr2_context_thread_func+0x253/0x920 drivers/media/usb/pvrusb2/pvrusb2-context.c:158 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 5993: 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:2687 [inline] slab_free mm/slub.c:6124 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6442 v4l2_ctrl_handler_free drivers/media/v4l2-core/v4l2-ctrls-core.c:1765 [inline] v4l2_ctrl_handler_free+0x552/0x970 drivers/media/v4l2-core/v4l2-ctrls-core.c:1737 i2c_device_remove+0x81/0x280 drivers/i2c/i2c-core-base.c:631 device_remove+0xcb/0x180 drivers/base/dd.c:571 __device_release_driver drivers/base/dd.c:1284 [inline] device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1307 bus_remove_device+0x22f/0x440 drivers/base/bus.c:616 device_del+0x376/0x9b0 drivers/base/core.c:3878 device_unregister+0x1d/0xe0 drivers/base/core.c:3919 i2c_unregister_device+0xf5/0x270 drivers/i2c/i2c-core-base.c:1075 __unregister_client drivers/i2c/i2c-core-base.c:1730 [inline] __unregister_client+0x80/0xa0 drivers/i2c/i2c-core-base.c:1726 device_for_each_child+0x11e/0x1a0 drivers/base/core.c:4018 i2c_del_adapter+0x4a7/0x820 drivers/i2c/i2c-core-base.c:1793 pvr2_i2c_core_done+0x72/0xd0 drivers/media/usb/pvrusb2/pvrusb2-i2c-core.c:652 pvr2_hdw_disconnect+0xcb/0x600 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2711 pvr2_context_disconnect+0x32/0xc0 drivers/media/usb/pvrusb2/pvrusb2-context.c:269 pvr_disconnect+0x80/0xd0 drivers/media/usb/pvrusb2/pvrusb2-main.c:79 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:573 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:565 __device_release_driver drivers/base/dd.c:1284 [inline] device_release_driver_internal+0x42e/0x600 drivers/base/dd.c:1307 bus_remove_device+0x22f/0x440 drivers/base/bus.c:616 device_del+0x376/0x9b0 drivers/base/core.c:3878 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1418 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1d0c/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888021487600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of freed 256-byte region [ffff888021487600, ffff888021487700) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21486 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 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842b40 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0000852181 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 18722644541, free_ts 12633345553 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1888 prep_new_page mm/page_alloc.c:1896 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3961 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5249 alloc_slab_page mm/slub.c:3255 [inline] allocate_slab mm/slub.c:3444 [inline] new_slab+0xa6/0x6d0 mm/slub.c:3502 refill_objects+0x26b/0x400 mm/slub.c:7134 refill_sheaf mm/slub.c:2804 [inline] alloc_full_sheaf mm/slub.c:2825 [inline] __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4588 alloc_from_pcs mm/slub.c:4681 [inline] slab_alloc_node mm/slub.c:4815 [inline] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5334 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] bus_add_driver+0x92/0x5b0 drivers/base/bus.c:699 driver_register+0x1e2/0x360 drivers/base/driver.c:249 usb_register_driver drivers/usb/core/driver.c:1078 [inline] usb_register_driver+0x21c/0x3e0 drivers/usb/core/driver.c:1060 do_one_initcall+0x11d/0x760 init/main.c:1382 do_initcall_level init/main.c:1444 [inline] do_initcalls init/main.c:1460 [inline] do_basic_setup init/main.c:1479 [inline] kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692 kernel_init+0x1f/0x1e0 init/main.c:1582 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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:1432 [inline] __free_frozen_pages+0x7ca/0x10a0 mm/page_alloc.c:2977 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] __kmalloc_cache_noprof+0x243/0x6f0 mm/slub.c:5334 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] bus_add_driver+0x92/0x5b0 drivers/base/bus.c:699 driver_register+0x1e2/0x360 drivers/base/driver.c:249 e1000_init_module+0x46/0xb0 drivers/net/ethernet/intel/e1000/e1000_main.c:224 do_one_initcall+0x11d/0x760 init/main.c:1382 do_initcall_level init/main.c:1444 [inline] do_initcalls init/main.c:1460 [inline] do_basic_setup init/main.c:1479 [inline] kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692 kernel_init+0x1f/0x1e0 init/main.c:1582 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888021487500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888021487580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888021487600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021487680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021487700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 57 push %rdi 1: 56 push %rsi 2: 53 push %rbx 3: 8b 44 24 14 mov 0x14(%rsp),%eax 7: f6 00 08 testb $0x8,(%rax) a: 75 23 jne 0x2f c: 8b 44 24 18 mov 0x18(%rsp),%eax 10: 8b 5c 24 1c mov 0x1c(%rsp),%ebx 14: 8b 4c 24 20 mov 0x20(%rsp),%ecx 18: 8b 54 24 24 mov 0x24(%rsp),%edx 1c: 8b 74 24 28 mov 0x28(%rsp),%esi 20: 8b 7c 24 2c mov 0x2c(%rsp),%edi 24: 8b 6c 24 30 mov 0x30(%rsp),%ebp 28: cd 80 int $0x80 * 2a: 5b pop %rbx <-- trapping instruction 2b: 5e pop %rsi 2c: 5f pop %rdi 2d: 5d pop %rbp 2e: c3 ret 2f: 5b pop %rbx 30: 5e pop %rsi 31: 5f pop %rdi 32: 5d pop %rbp 33: e9 f7 a1 ff ff jmp 0xffffa22f 38: 66 90 xchg %ax,%ax 3a: 66 90 xchg %ax,%ax 3c: 66 90 xchg %ax,%ax 3e: 90 nop 3f: 53 push %rbx