IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready ================================================================== BUG: KASAN: use-after-free in snd_seq_timer_interrupt+0x2c8/0x370 sound/core/seq/seq_timer.c:145 Read of size 8 at addr ffff8880ab97fd18 by task systemd-udevd/4696 CPU: 0 PID: 4696 Comm: systemd-udevd Not tainted 4.19.204-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 print_address_description.cold.6+0x9/0x211 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:396 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 snd_seq_timer_interrupt+0x2c8/0x370 sound/core/seq/seq_timer.c:145 snd_timer_interrupt sound/core/timer.c:877 [inline] snd_timer_interrupt+0x617/0x1080 sound/core/timer.c:789 snd_timer_s_function+0xa7/0x120 sound/core/timer.c:1116 call_timer_fn+0x14c/0x510 kernel/time/timer.c:1338 expire_timers+0x255/0x3a0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x1dc/0x570 kernel/time/timer.c:1709 __do_softirq+0x25f/0x919 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13e/0x540 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:fast_dput fs/dcache.c:728 [inline] RIP: 0010:dput+0xa6/0x460 fs/dcache.c:833 Code: 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e dd 02 00 00 f6 03 08 4c 8d ab 80 00 00 00 4c 89 ef 0f 85 5e 02 00 00 e8 ba 6f a9 01 <85> c0 0f 88 63 02 00 00 75 50 48 89 d8 48 c1 e8 03 42 0f b6 14 20 RSP: 0018:ffff88809d83f8b0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 00000000ffffffff RBX: ffff8880ade56460 RCX: ffffffff814c5a51 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880ade564e0 RBP: ffff88809d83f8d8 R08: ffffed1017444553 R09: ffffed1017444552 R10: ffffed1017444552 R11: ffff8880ba222a93 R12: dffffc0000000000 R13: ffff8880ade564e0 R14: ffffffff819a3c5a R15: ffff88809d83f9f8 path_to_nameidata fs/namei.c:838 [inline] step_into fs/namei.c:1777 [inline] walk_component+0x4a7/0xf10 fs/namei.c:1830 link_path_walk.part.11+0x6a2/0xf50 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_lookupat.isra.13+0x1aa/0x840 fs/namei.c:2318 filename_lookup.part.21+0x160/0x360 fs/namei.c:2349 filename_lookup fs/namei.c:2342 [inline] user_path_at_empty+0x39/0x40 fs/namei.c:2609 do_readlinkat+0xcc/0x2b0 fs/stat.c:394 __do_sys_readlinkat fs/stat.c:421 [inline] __se_sys_readlinkat fs/stat.c:418 [inline] __x64_sys_readlinkat+0x92/0xf0 fs/stat.c:418 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f53dd8050ba Code: 48 8b 0d e1 bd 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 0b 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ae bd 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007fff344bfd98 EFLAGS: 00000202 ORIG_RAX: 000000000000010b RAX: ffffffffffffffda RBX: 000056094a236a40 RCX: 00007f53dd8050ba RDX: 000056094a236a40 RSI: 000056094a248580 RDI: 00000000ffffff9c RBP: 0000000000000064 R08: 0000560948607670 R09: 0000000000000070 R10: 0000000000000063 R11: 0000000000000202 R12: 000056094a248580 R13: 00000000ffffff9c R14: 00007fff344bfdf0 R15: 0000000000000063 Allocated by task 10150: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:553 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:538 kmem_cache_alloc_trace+0x152/0x3a0 mm/slab.c:3625 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] queue_new sound/core/seq/seq_queue.c:113 [inline] snd_seq_queue_alloc+0x52/0x4d0 sound/core/seq/seq_queue.c:185 snd_seq_ioctl_create_queue+0xaa/0x2e0 sound/core/seq/seq_clientmgr.c:1531 snd_seq_ioctl+0x1c6/0x3e0 sound/core/seq/seq_clientmgr.c:2140 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 10145: save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x13c/0x220 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kfree+0xcf/0x220 mm/slab.c:3822 queue_delete+0x8b/0xa0 sound/core/seq/seq_queue.c:156 snd_seq_queue_client_leave+0x27/0x110 sound/core/seq/seq_queue.c:592 seq_free_client1.part.8+0xef/0x260 sound/core/seq/seq_clientmgr.c:263 seq_free_client1 sound/core/seq/seq_clientmgr.c:256 [inline] seq_free_client+0x5c/0xd0 sound/core/seq/seq_clientmgr.c:285 snd_seq_release+0x48/0xe0 sound/core/seq/seq_clientmgr.c:366 __fput+0x249/0x7f0 fs/file_table.c:278 ____fput+0x9/0x10 fs/file_table.c:309 task_work_run+0x108/0x180 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x185/0x1e0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880ab97fcc0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 88 bytes inside of 512-byte region [ffff8880ab97fcc0, ffff8880ab97fec0) The buggy address belongs to the page: page:ffffea0002ae5fc0 count:1 mapcount:0 mapping:ffff88813bff6940 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffffea00027cf7c8 ffffea0002965208 ffff88813bff6940 raw: 0000000000000000 ffff8880ab97f040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880ab97fc00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880ab97fc80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8880ab97fd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880ab97fd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880ab97fe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 03 42 0f add 0xf(%rdx),%eax 3: b6 04 mov $0x4,%dh 5: 20 84 c0 74 08 3c 03 and %al,0x33c0874(%rax,%rax,8) c: 0f 8e dd 02 00 00 jle 0x2ef 12: f6 03 08 testb $0x8,(%rbx) 15: 4c 8d ab 80 00 00 00 lea 0x80(%rbx),%r13 1c: 4c 89 ef mov %r13,%rdi 1f: 0f 85 5e 02 00 00 jne 0x283 25: e8 ba 6f a9 01 callq 0x1a96fe4 * 2a: 85 c0 test %eax,%eax <-- trapping instruction 2c: 0f 88 63 02 00 00 js 0x295 32: 75 50 jne 0x84 34: 48 89 d8 mov %rbx,%rax 37: 48 c1 e8 03 shr $0x3,%rax 3b: 42 0f b6 14 20 movzbl (%rax,%r12,1),%edx