Re: WARNING in binder_transaction_buffer_release

[Eric Biggers]

On Mon, May 20, 2019 at 07:18:06AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    72cf0b07 Merge tag 'sound-fix-5.2-rc1' of git://git.kernel..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17c7d4bca00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d103f114f9010324
> dashboard link: https://syzkaller.appspot.com/bug?extid=8b3c354d33c4ac78bfad
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> userspace arch: i386
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15b99b44a00000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+8b3c354d33c4ac78bfad@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> WARNING: CPU: 1 PID: 8535 at drivers/android/binder.c:2368
> binder_transaction_buffer_release+0x673/0x8f0 drivers/android/binder.c:2368
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 1 PID: 8535 Comm: syz-executor.2 Not tainted 5.1.0+ #19
> 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+0x172/0x1f0 lib/dump_stack.c:113
>  panic+0x2cb/0x715 kernel/panic.c:214
>  __warn.cold+0x20/0x4c kernel/panic.c:571
>  report_bug+0x263/0x2b0 lib/bug.c:186
>  fixup_bug arch/x86/kernel/traps.c:179 [inline]
>  fixup_bug arch/x86/kernel/traps.c:174 [inline]
>  do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
>  do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
>  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
> RIP: 0010:binder_transaction_buffer_release+0x673/0x8f0
> drivers/android/binder.c:2368
> Code: 31 ff 41 89 c5 89 c6 e8 7b 04 1f fc 45 85 ed 0f 85 1f 41 01 00 49 8d
> 47 40 48 89 85 50 fe ff ff e9 9d fa ff ff e8 dd 02 1f fc <0f> 0b e9 7f fc ff
> ff e8 d1 02 1f fc 48 89 d8 45 31 c9 4c 89 fe 4c
> RSP: 0018:ffff88807b2775f0 EFLAGS: 00010293
> RAX: ffff888092b1e040 RBX: 0000000000000060 RCX: 1ffff11012563caa
> RDX: 0000000000000000 RSI: ffffffff85519e13 RDI: ffff888097a2d248
> RBP: ffff88807b2777d8 R08: ffff888092b1e040 R09: ffffed100f64eee3
> R10: ffffed100f64eee2 R11: ffff88807b277717 R12: ffff88808fd2c340
> R13: 0000000000000068 R14: ffff88807b2777b0 R15: ffff88809f7ea580
>  binder_transaction+0x153d/0x6620 drivers/android/binder.c:3484
>  binder_thread_write+0x87e/0x2820 drivers/android/binder.c:3792
>  binder_ioctl_write_read drivers/android/binder.c:4836 [inline]
>  binder_ioctl+0x102f/0x1833 drivers/android/binder.c:5013
>  __do_compat_sys_ioctl fs/compat_ioctl.c:1052 [inline]
>  __se_compat_sys_ioctl fs/compat_ioctl.c:998 [inline]
>  __ia32_compat_sys_ioctl+0x195/0x620 fs/compat_ioctl.c:998
>  do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
>  do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
>  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
> RIP: 0023:0xf7f9e849
> Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90
> 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90
> 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
> RSP: 002b:00000000f7f9a0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
> RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000c0306201
> RDX: 0000000020000140 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> Kernel Offset: disabled
> Rebooting in 86400 seconds..
> 
> 
> ---
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> 
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> 

Are any of the binder maintainers planning to fix this?  This seems to be the
only open syzbot report for binder on the upstream kernel.

- Eric