================================================================== BUG: KASAN: slab-use-after-free in timer_is_static_object+0x78/0x90 kernel/time/timer.c:680 Read of size 8 at addr ffff88801b7de398 by task syz-executor.2/18571 CPU: 3 PID: 18571 Comm: syz-executor.2 Not tainted 6.6.0-rc2-syzkaller-00018-g2cf0f7156238 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 timer_is_static_object+0x78/0x90 kernel/time/timer.c:680 lookup_object_or_alloc.part.0+0x6b2/0xaf0 lib/debugobjects.c:581 lookup_object_or_alloc lib/debugobjects.c:567 [inline] debug_object_assert_init+0x2be/0x370 lib/debugobjects.c:929 debug_timer_assert_init kernel/time/timer.c:792 [inline] debug_assert_init kernel/time/timer.c:837 [inline] __timer_delete+0x81/0x1c0 kernel/time/timer.c:1321 del_timer include/linux/timer.h:213 [inline] try_to_grab_pending+0x7e/0x850 kernel/workqueue.c:1564 __cancel_work+0x85/0x340 kernel/workqueue.c:3582 hci_conn_drop include/net/bluetooth/hci_core.h:1548 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1519 [inline] __sco_sock_close+0x34d/0x690 net/bluetooth/sco.c:444 sco_sock_close net/bluetooth/sco.c:469 [inline] sco_sock_release+0x6f/0x2c0 net/bluetooth/sco.c:1246 __sock_release+0xae/0x260 net/socket.c:659 sock_close+0x1c/0x20 net/socket.c:1402 __fput+0x3f7/0xa70 fs/file_table.c:384 __fput_sync+0x47/0x50 fs/file_table.c:465 __do_sys_close fs/open.c:1572 [inline] __se_sys_close fs/open.c:1557 [inline] __ia32_sys_close+0x87/0xf0 fs/open.c:1557 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7f03579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000fff65480 EFLAGS: 00000293 ORIG_RAX: 0000000000000006 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000056f10400 RDX: 0000000000000000 RSI: 00000000f7353ff4 RDI: 000000000001e864 RBP: 00000000f737c0c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 18572: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] hci_conn_add+0xc2/0x1760 net/bluetooth/hci_conn.c:957 hci_connect_sco+0x3a0/0xf80 net/bluetooth/hci_conn.c:1692 sco_connect net/bluetooth/sco.c:266 [inline] sco_sock_connect+0x2c7/0xa50 net/bluetooth/sco.c:591 __sys_connect_file+0x15b/0x1a0 net/socket.c:2033 __sys_connect+0x145/0x170 net/socket.c:2050 __do_sys_connect net/socket.c:2060 [inline] __se_sys_connect net/socket.c:2057 [inline] __ia32_sys_connect+0x71/0xb0 net/socket.c:2057 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Freed by task 5185: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 device_release+0xa1/0x240 drivers/base/core.c:2484 kobject_cleanup lib/kobject.c:682 [inline] kobject_release lib/kobject.c:716 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1d0/0x440 lib/kobject.c:733 put_device+0x1f/0x30 drivers/base/core.c:3732 hci_abort_conn_sync+0xabf/0xe10 net/bluetooth/hci_sync.c:5435 abort_conn_sync+0x187/0x390 net/bluetooth/hci_conn.c:2894 hci_cmd_sync_work+0x1a4/0x3c0 net/bluetooth/hci_sync.c:306 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 The buggy address belongs to the object at ffff88801b7de000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 920 bytes inside of freed 4096-byte region [ffff88801b7de000, ffff88801b7df000) The buggy address belongs to the physical page: page:ffffea00006df600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b7d8 head:ffffea00006df600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012c43040 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 7955976567, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 alloc_page_interleave+0x1e/0x250 mm/mempolicy.c:2131 alloc_pages+0x22a/0x270 mm/mempolicy.c:2293 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517 kmalloc_trace+0x25/0xe0 mm/slab_common.c:1114 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] kobject_uevent_env+0x24c/0x1800 lib/kobject_uevent.c:524 disk_uevent+0x12b/0x4d0 block/genhd.c:335 device_add_disk+0xded/0x11f0 block/genhd.c:517 add_disk include/linux/blkdev.h:735 [inline] loop_add+0x87f/0xaf0 drivers/block/loop.c:2087 loop_init+0x164/0x270 drivers/block/loop.c:2279 do_one_initcall+0x117/0x630 init/main.c:1232 page_owner free stack trace missing Memory state around the buggy address: ffff88801b7de280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b7de300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801b7de380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b7de400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801b7de480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi