sound: use-after-free in snd_timer_interrupt

From: Dmitry Vyukov
Date: Sat Apr 02 2016 - 05:09:12 EST

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Hello,

I am hitting the following use-after-free while running syzkaller
fuzzer on commit 8e0f93cda48ed054e1216bab5c60017e1a5fc1e8

==================================================================
BUG: KASAN: use-after-free in __list_del_entry+0x1d3/0x1e0 at addr
ffff88002ebf6e20
Read of size 8 by task syz-executor/7684
=============================================================================
BUG kmalloc-256 (Not tainted): kasan: bad access detected
-----------------------------------------------------------------------------

INFO: Allocated in snd_timer_instance_new+0x52/0x3a0 age=5 cpu=0 pid=7693
[< none >] ___slab_alloc+0x578/0x5d0 mm/slub.c:2464
[< none >] __slab_alloc+0x66/0xc0 mm/slub.c:2493
[< inline >] slab_alloc_node mm/slub.c:2556
[< inline >] slab_alloc mm/slub.c:2598
[< none >] kmem_cache_alloc_trace+0x242/0x3b0 mm/slub.c:2615
[< inline >] kmalloc include/linux/slab.h:463
[< inline >] kzalloc include/linux/slab.h:607
[< none >] snd_timer_instance_new+0x52/0x3a0 sound/core/timer.c:106
[< none >] snd_timer_open+0x522/0xd20 sound/core/timer.c:289
[< inline >] snd_timer_user_tselect sound/core/timer.c:1612
[< inline >] __snd_timer_user_ioctl sound/core/timer.c:1888
[< none >] snd_timer_user_ioctl+0x8f4/0x2490 sound/core/timer.c:1918
[< inline >] vfs_ioctl fs/ioctl.c:43
[< none >] do_vfs_ioctl+0x18c/0xfb0 fs/ioctl.c:674
[< inline >] SYSC_ioctl fs/ioctl.c:689
[< none >] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680
[< none >] entry_SYSCALL_64_fastpath+0x16/0x7a
arch/x86/entry/entry_64.S:185

INFO: Freed in snd_timer_close+0x3ee/0x750 age=9 cpu=0 pid=7693
[< none >] __slab_free+0x1fc/0x320 mm/slub.c:2674
[< inline >] slab_free mm/slub.c:2829
[< none >] kfree+0x2f5/0x370 mm/slub.c:3660
[< none >] snd_timer_close+0x3ee/0x750 sound/core/timer.c:375
[< inline >] snd_timer_user_tselect sound/core/timer.c:1602
[< inline >] __snd_timer_user_ioctl sound/core/timer.c:1888
[< none >] snd_timer_user_ioctl+0x7cd/0x2490 sound/core/timer.c:1918
[< inline >] vfs_ioctl fs/ioctl.c:43
[< none >] do_vfs_ioctl+0x18c/0xfb0 fs/ioctl.c:674
[< inline >] SYSC_ioctl fs/ioctl.c:689
[< none >] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680
[< none >] entry_SYSCALL_64_fastpath+0x16/0x7a
arch/x86/entry/entry_64.S:185

INFO: Slab 0xffffea0000bafd00 objects=22 used=11 fp=0xffff88002ebf6d80
flags=0x1fffc0000004080
INFO: Object 0xffff88002ebf6d80 @offset=11648 fp=0xffff88002ebf5110
CPU: 3 PID: 7684 Comm: syz-executor Tainted: G B 4.5.0-rc7+ #337
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
ffffffff87b7d480 ffff88006d707bb0 ffffffff82c2125f ffffffff00bafd00
fffffbfff0f6fa90 ffff88003e807000 ffff88002ebf6d80 ffff88002ebf4000
ffffea0000bafd00 ffff88002ebf6e18 ffff88006d707be0 ffffffff8176dcc4

Call Trace:
[<ffffffff81777e4e>] __asan_report_load8_noabort+0x3e/0x40
mm/kasan/report.c:295
[<ffffffff82c88f63>] __list_del_entry+0x1d3/0x1e0 lib/list_debug.c:48
[< inline >] list_del_init include/linux/list.h:145
[<ffffffff852942f9>] snd_timer_interrupt+0x5b9/0xc80 sound/core/timer.c:791
[<ffffffff8529acc9>] snd_hrtimer_callback+0x169/0x230 sound/core/hrtimer.c:54
[< inline >] __run_hrtimer kernel/time/hrtimer.c:1248
[<ffffffff814c3911>] __hrtimer_run_queues+0x331/0xe90
kernel/time/hrtimer.c:1312
[<ffffffff814c62e2>] hrtimer_interrupt+0x182/0x430 kernel/time/hrtimer.c:1346
[<ffffffff81255ec2>] local_apic_timer_interrupt+0x72/0xe0
arch/x86/kernel/apic/apic.c:907
[<ffffffff812593e9>] smp_apic_timer_interrupt+0x79/0xa0
arch/x86/kernel/apic/apic.c:931
[<ffffffff866d256c>] apic_timer_interrupt+0x8c/0xa0
arch/x86/entry/entry_64.S:520
[< inline >] spin_unlock_irqrestore include/linux/spinlock.h:362
[<ffffffff8177369e>] __slab_free+0x1ae/0x320 mm/slub.c:2681
[< inline >] slab_free mm/slub.c:2829
[<ffffffff81773ed8>] kmem_cache_free+0x318/0x440 mm/slub.c:2838
[<ffffffff81704cb8>] ptlock_free+0x38/0x50 mm/memory.c:3912
[< inline >] pgtable_pmd_page_dtor include/linux/mm.h:1702
[<ffffffff812951ca>] ___pmd_free_tlb+0xaa/0x110 arch/x86/mm/pgtable.c:74
[< inline >] __pmd_free_tlb ./arch/x86/include/asm/pgalloc.h:106
[< inline >] free_pmd_range mm/memory.c:432
[< inline >] free_pud_range mm/memory.c:450
[<ffffffff816f4dc3>] free_pgd_range+0x973/0xbe0 mm/memory.c:526
[<ffffffff816f52f5>] free_pgtables+0x2c5/0x3b0 mm/memory.c:558
[<ffffffff817137c3>] exit_mmap+0x233/0x410 mm/mmap.c:2868
[<ffffffff813543f5>] mmput+0x95/0x230 kernel/fork.c:706
[< inline >] exit_mm kernel/exit.c:436
[<ffffffff81366eb2>] do_exit+0x7b2/0x2d00 kernel/exit.c:735
[<ffffffff81369578>] do_group_exit+0x108/0x330 kernel/exit.c:878
[<ffffffff8138cf14>] get_signal+0x634/0x15e0 kernel/signal.c:2307
[<ffffffff811a7db3>] do_signal+0x83/0x1c90 arch/x86/kernel/signal.c:712
[<ffffffff81006685>] exit_to_usermode_loop+0x1a5/0x210
arch/x86/entry/common.c:247
[< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:282
[<ffffffff8100866a>] syscall_return_slowpath+0x2ba/0x340
arch/x86/entry/common.c:344
[<ffffffff866d18e2>] int_ret_from_sys_call+0x25/0x9f
arch/x86/entry/entry_64.S:281

==================================================================
kasan: GPF could be caused by NULL-ptr deref or user memory
accessgeneral protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
Modules linked in:
CPU: 3 PID: 7684 Comm: syz-executor Tainted: G B 4.5.0-rc7+ #337
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff880061062f80 ti: ffff88005ee10000 task.ti: ffff88005ee10000
RIP: 0010:[<ffffffff82c88e16>] [<ffffffff82c88e16>] __list_del_entry+0x86/0x1e0
RSP: 0018:ffff88006d707cd0 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88002ebf6e18
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88006d707cf0 R08: ffffffff89cbcf00 R09: 0000000000000000
R10: ffffed000dae0f8c R11: 0000000000000000 R12: ffff88005ee0d120
R13: ffff8800670a2298 R14: ffff88005ee0d110 R15: ffff88002ebf6e18
FS: 0000000000000000(0000) GS:ffff88006d700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000006e0000 CR3: 0000000007ae9000 CR4: 00000000000006e0
Stack:
ffff88006d707cf0 ffff88002ebf6e18 dffffc0000000000 ffff88005ee0d120
ffff88006d707db0 ffffffff852942f9 ffff8800670a2368 0000000000000082
dffffc0000000000 ffff8800670a234c ffffffff87b7d480 ffffed000ce1446d
Call Trace:
<IRQ>
[< inline >] list_del_init include/linux/list.h:145
[<ffffffff852942f9>] snd_timer_interrupt+0x5b9/0xc80 sound/core/timer.c:791
[<ffffffff8529acc9>] snd_hrtimer_callback+0x169/0x230 sound/core/hrtimer.c:54
[< inline >] __run_hrtimer kernel/time/hrtimer.c:1248
[<ffffffff814c3911>] __hrtimer_run_queues+0x331/0xe90
kernel/time/hrtimer.c:1312
[<ffffffff814c62e2>] hrtimer_interrupt+0x182/0x430 kernel/time/hrtimer.c:1346
[<ffffffff81255ec2>] local_apic_timer_interrupt+0x72/0xe0
arch/x86/kernel/apic/apic.c:907
[<ffffffff812593e9>] smp_apic_timer_interrupt+0x79/0xa0
arch/x86/kernel/apic/apic.c:931
[<ffffffff866d256c>] apic_timer_interrupt+0x8c/0xa0
arch/x86/entry/entry_64.S:520
<EOI>
[< inline >] spin_unlock_irqrestore include/linux/spinlock.h:362
[<ffffffff8177369e>] __slab_free+0x1ae/0x320 mm/slub.c:2681
[< inline >] slab_free mm/slub.c:2829
[<ffffffff81773ed8>] kmem_cache_free+0x318/0x440 mm/slub.c:2838
[<ffffffff81704cb8>] ptlock_free+0x38/0x50 mm/memory.c:3912
[< inline >] pgtable_pmd_page_dtor include/linux/mm.h:1702
[<ffffffff812951ca>] ___pmd_free_tlb+0xaa/0x110 arch/x86/mm/pgtable.c:74
[< inline >] __pmd_free_tlb ./arch/x86/include/asm/pgalloc.h:106
[< inline >] free_pmd_range mm/memory.c:432
[< inline >] free_pud_range mm/memory.c:450
[<ffffffff816f4dc3>] free_pgd_range+0x973/0xbe0 mm/memory.c:526
[<ffffffff816f52f5>] free_pgtables+0x2c5/0x3b0 mm/memory.c:558
[<ffffffff817137c3>] exit_mmap+0x233/0x410 mm/mmap.c:2868
[<ffffffff813543f5>] mmput+0x95/0x230 kernel/fork.c:706
[< inline >] exit_mm kernel/exit.c:436
[<ffffffff81366eb2>] do_exit+0x7b2/0x2d00 kernel/exit.c:735
[<ffffffff81369578>] do_group_exit+0x108/0x330 kernel/exit.c:878
[<ffffffff8138cf14>] get_signal+0x634/0x15e0 kernel/signal.c:2307
[<ffffffff811a7db3>] do_signal+0x83/0x1c90 arch/x86/kernel/signal.c:712
[<ffffffff81006685>] exit_to_usermode_loop+0x1a5/0x210
arch/x86/entry/common.c:247
[< inline >] prepare_exit_to_usermode arch/x86/entry/common.c:282
[<ffffffff8100866a>] syscall_return_slowpath+0x2ba/0x340
arch/x86/entry/common.c:344
[<ffffffff866d18e2>] int_ret_from_sys_call+0x25/0x9f
arch/x86/entry/entry_64.S:281
Code: c0 0f 84 91 00 00 00 48 b8 00 02 00 00 00 00 ad de 48 39 c3 0f
84 9f 00 00 00 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
3c 02 00 0f 85 f6 00 00 00 4c 8b 23 4c 39 e1 0f 85 95 00 00
RIP [<ffffffff82c88e16>] __list_del_entry+0x86/0x1e0 lib/list_debug.c:57
RSP <ffff88006d707cd0>
---[ end trace fd16e1eaa1720656 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Shutting down cpus with NMI
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Fatal exception in interrupt

It is not easily reproducible. I've hit several times while running
fuzzer for a week. Here is one of the logs for the record:
https://gist.githubusercontent.com/dvyukov/c84798ee55721563ecb537c4d51dc9f5/raw/f00b865a85877656f13b41917f7321730f140d35/gistfile1.txt

Next message: Guodong Xu: "[PATCH v2 00/16] DTS for hi6220 and HiKey"
Previous message: bbban: "Jeg er på jagt efter partner."
Next in thread: Takashi Iwai: "Re: sound: use-after-free in snd_timer_interrupt"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]