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Date:   Wed, 14 Oct 2020 10:00:30 -0700
Message-ID: <0000000000000c3be205b1a4782f@google.com>
Subject: general protection fault in __se_sys_io_uring_register
From:   syzbot <syzbot+4520eff3d84059553f13@syzkaller.appspotmail.com>
To:     axboe@kernel.dk, io-uring@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk
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Hello,

syzbot found the following issue on:

HEAD commit:    029f56db Merge tag 'x86_asm_for_v5.10' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1421c89b900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c5327fbeef7650a
dashboard link: https://syzkaller.appspot.com/bug?extid=4520eff3d84059553f13
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)

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+4520eff3d84059553f13@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 8347 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register fs/io_uring.c:9553 [inline]
RIP: 0010:__se_sys_io_uring_register+0x3343/0x3ea0 fs/io_uring.c:9535
Code: ff df 48 8b 5c 24 18 42 80 3c 23 00 48 8b 6c 24 60 74 08 48 89 ef e8 bc 36 e0 ff 41 8d 5e ff 4c 8b 7d 00 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 9e 36 e0 ff 89 d8 c1 f8 09 48 63
RSP: 0018:ffffc9001633fdc0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff11011eb5638
RDX: ffff888051844080 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88808f5ab1b8 R08: ffffffff81d56c63 R09: ffffed1012046ab8
R10: ffffed1012046ab8 R11: 0000000000000000 R12: dffffc0000000000
R13: 00000000fffffff7 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f5b96b14700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000768000 CR3: 000000009ed9c000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de59
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5b96b13c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 00000000000083c0 RCX: 000000000045de59
RDX: 0000000020000040 RSI: 0000000000000002 RDI: 0000000000000003
RBP: 000000000118bf68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffcf7ec75bf R14: 00007f5b96b149c0 R15: 000000000118bf2c
Modules linked in:
---[ end trace ae2cc3c0d259d867 ]---
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register fs/io_uring.c:9553 [inline]
RIP: 0010:__se_sys_io_uring_register+0x3343/0x3ea0 fs/io_uring.c:9535
Code: ff df 48 8b 5c 24 18 42 80 3c 23 00 48 8b 6c 24 60 74 08 48 89 ef e8 bc 36 e0 ff 41 8d 5e ff 4c 8b 7d 00 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 ff e8 9e 36 e0 ff 89 d8 c1 f8 09 48 63
RSP: 0018:ffffc9001633fdc0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff11011eb5638
RDX: ffff888051844080 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88808f5ab1b8 R08: ffffffff81d56c63 R09: ffffed1012046ab8
R10: ffffed1012046ab8 R11: 0000000000000000 R12: dffffc0000000000
R13: 00000000fffffff7 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f5b96b14700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000768000 CR3: 000000009ed9c000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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