Re: general protection fault in map_vdso_randomized

[Dmitry Vyukov]

On Fri, Aug 21, 2020 at 8:10 AM syzbot
<syzbot+6719f65e8a293105edcc@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    4b6c093e Merge tag 'block-5.9-2020-08-14' of git://git.ker..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=179f99f6900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a98b778f5fca0653
> dashboard link: https://syzkaller.appspot.com/bug?extid=6719f65e8a293105edcc
> compiler:       gcc (GCC) 10.1.0-syz 20200507
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+6719f65e8a293105edcc@xxxxxxxxxxxxxxxxxxxxxxxxx

#syz dup: general protection fault in perf_misc_flags

> general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> CPU: 0 PID: 27621 Comm: modprobe Not tainted 5.8.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:map_vdso_randomized+0x64/0x160 arch/x86/entry/vdso/vma.c:364
> Code: 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 eb 00 00 00 65 48 8b 1c 25 c0 fe 01 00 48 8d bb 28 04 00 00 41 2b 54 24 20 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> RSP: 0018:ffffc9000ab57c10 EFLAGS: 00010207
> RAX: dffffc0000000000 RBX: ffff88804e0963c0 RCX: 1ffffffff1080a60
> RDX: 0000000000006000 RSI: 0000000000000001 RDI: ffff88804e0967e8
> RBP: ffff88801459b000 R08: 0000000000000001 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000160 R12: ffffffff884052e0
> R13: ffff8880a69cf950 R14: 00007faba47c2c20 R15: ffff8880a5cb4400
> FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007faba49e6fc0 CR3: 0000000031b89000 CR4: 00000000001506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  load_elf_binary+0x22d4/0x47c0 fs/binfmt_elf.c:1221
>  search_binary_handler fs/exec.c:1819 [inline]
>  exec_binprm fs/exec.c:1860 [inline]
>  bprm_execve+0x936/0x1b10 fs/exec.c:1931
>  kernel_execve+0x370/0x460 fs/exec.c:2080
>  call_usermodehelper_exec_async+0x27a/0x500 kernel/umh.c:101
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> Modules linked in:
> ---[ end trace f344c46c1e164ddf ]---
> RIP: 0010:map_vdso_randomized+0x64/0x160 arch/x86/entry/vdso/vma.c:364
> Code: 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 eb 00 00 00 65 48 8b 1c 25 c0 fe 01 00 48 8d bb 28 04 00 00 41 2b 54 24 20 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> RSP: 0018:ffffc9000ab57c10 EFLAGS: 00010207
> RAX: dffffc0000000000 RBX: ffff88804e0963c0 RCX: 1ffffffff1080a60
> RDX: 0000000000006000 RSI: 0000000000000001 RDI: ffff88804e0967e8
> RBP: ffff88801459b000 R08: 0000000000000001 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000160 R12: ffffffff884052e0
> R13: ffff8880a69cf950 R14: 00007faba47c2c20 R15: ffff8880a5cb4400
> FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007ffc99314e38 CR3: 0000000031b89000 CR4: 00000000001506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>
>
> ---
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