================================================================== BUG: KASAN: use-after-free in snd_seq_timer_interrupt+0x2d4/0x340 sound/core/seq/seq_timer.c:145 Read of size 8 at addr ffff8880a90c8398 by task syz-executor976/7975 CPU: 0 PID: 7975 Comm: syz-executor976 Not tainted 4.14.241-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430 snd_seq_timer_interrupt+0x2d4/0x340 sound/core/seq/seq_timer.c:145 snd_timer_interrupt.part.0+0x8ea/0xe20 sound/core/timer.c:870 snd_timer_interrupt sound/core/timer.c:1106 [inline] snd_timer_s_function+0x12c/0x1b0 sound/core/timer.c:1106 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:__orc_find+0x20/0xf0 arch/x86/kernel/unwind_orc.c:46 RSP: 0018:ffff8880a2b377d8 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000002 RBX: 1ffff11014566f0b RCX: ffffffff87400089 RDX: 0000000000000002 RSI: ffffffff8ae11afc RDI: ffffffff8a6308c0 RBP: 0000000000000001 R08: ffffffff8ae11afc R09: ffffffff8ae11b08 R10: 0000000000146546 R11: 0000000000066071 R12: ffffffff8a6308c4 R13: ffff8880a2b37918 R14: ffff8880a2b37930 R15: ffff8880a2b378e0 orc_find arch/x86/kernel/unwind_orc.c:118 [inline] unwind_next_frame+0x59a/0x17d0 arch/x86/kernel/unwind_orc.c:348 __save_stack_trace+0x90/0x160 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc mm/slab.c:3390 [inline] kmem_cache_alloc+0x111/0x3c0 mm/slab.c:3550 anon_vma_chain_alloc mm/rmap.c:129 [inline] anon_vma_fork+0x1c0/0x580 mm/rmap.c:344 dup_mmap kernel/fork.c:664 [inline] dup_mm kernel/fork.c:1199 [inline] copy_mm kernel/fork.c:1254 [inline] copy_process.part.0+0x4c64/0x71c0 kernel/fork.c:1790 copy_process kernel/fork.c:1605 [inline] _do_fork+0x184/0xc80 kernel/fork.c:2091 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x43eb0b RSP: 002b:00007ffcc335a8e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 000000000043eb0b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000628300 R10: 00000000006285d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcc335a90c R14: 00007ffcc335a920 R15: 00007ffcc335a910 Allocated by task 8070: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] queue_new sound/core/seq/seq_queue.c:113 [inline] snd_seq_queue_alloc+0x51/0x4c0 sound/core/seq/seq_queue.c:195 snd_seq_ioctl_create_queue+0xa5/0x2f0 sound/core/seq/seq_clientmgr.c:1528 snd_seq_ioctl+0x1af/0x310 sound/core/seq/seq_clientmgr.c:2144 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 8070: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 snd_seq_queue_client_leave+0x2f/0x120 sound/core/seq/seq_queue.c:604 seq_free_client1.part.0+0xf0/0x270 sound/core/seq/seq_clientmgr.c:263 seq_free_client1 sound/core/seq/seq_clientmgr.c:256 [inline] seq_free_client+0x6c/0xe0 sound/core/seq/seq_clientmgr.c:285 snd_seq_release+0x4d/0xe0 sound/core/seq/seq_clientmgr.c:367 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa44/0x2850 kernel/exit.c:868 do_group_exit+0x100/0x2e0 kernel/exit.c:965 SYSC_exit_group kernel/exit.c:976 [inline] SyS_exit_group+0x19/0x20 kernel/exit.c:974 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880a90c8340 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 88 bytes inside of 512-byte region [ffff8880a90c8340, ffff8880a90c8540) The buggy address belongs to the page: page:ffffea0002a43200 count:1 mapcount:0 mapping:ffff8880a90c80c0 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff8880a90c80c0 0000000000000000 0000000100000006 raw: ffffea0002afcba0 ffffea0002afcbe0 ffff88813fe80940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a90c8280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880a90c8300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8880a90c8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a90c8400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a90c8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================