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Date:   Tue, 09 Jun 2020 18:48:13 -0700
Message-ID: <0000000000007a16f705a7b1096d@google.com>
Subject: upstream test error: BUG: using smp_processor_id() in preemptible
 code in ext4_mb_new_blocks
From:   syzbot <syzbot+0113b9be6667b5b50840@syzkaller.appspotmail.com>
To:     adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        tytso@mit.edu
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Sender: linux-ext4-owner@vger.kernel.org
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Hello,

syzbot found the following crash on:

HEAD commit:    5b14671b Merge tag 'fuse-update-5.8' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a11ec1100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d1ea633f7958e008
dashboard link: https://syzkaller.appspot.com/bug?extid=0113b9be6667b5b50840
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0113b9be6667b5b50840@syzkaller.appspotmail.com

BUG: using smp_processor_id() in preemptible [00000000] code: systemd-rfkill/6740
caller is ext4_mb_new_blocks+0xa77/0x3b30 fs/ext4/mballoc.c:4711
CPU: 0 PID: 6740 Comm: systemd-rfkill Not tainted 5.7.0-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+0x18f/0x20d lib/dump_stack.c:118
 check_preemption_disabled lib/smp_processor_id.c:47 [inline]
 debug_smp_processor_id.cold+0x88/0x9b lib/smp_processor_id.c:57
 ext4_mb_new_blocks+0xa77/0x3b30 fs/ext4/mballoc.c:4711
 ext4_ext_map_blocks+0x2044/0x3410 fs/ext4/extents.c:4244
 ext4_map_blocks+0x4cb/0x1640 fs/ext4/inode.c:626
 ext4_getblk+0xad/0x520 fs/ext4/inode.c:833
 ext4_bread+0x7c/0x380 fs/ext4/inode.c:883
 ext4_append+0x153/0x360 fs/ext4/namei.c:67
 ext4_init_new_dir fs/ext4/namei.c:2757 [inline]
 ext4_mkdir+0x5e0/0xdf0 fs/ext4/namei.c:2802
 vfs_mkdir+0x419/0x690 fs/namei.c:3641
 do_mkdirat+0x21e/0x280 fs/namei.c:3664
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7f449ff49687
Code: Bad RIP value.
RSP: 002b:00007ffdd3b9fe58 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00005567752fd985 RCX: 00007f449ff49687
RDX: 00007ffdd3b9fd20 RSI: 00000000000001ed RDI: 00005567752fd985
RBP: 00007f449ff49680 R08: 0000000000000100 R09: 0000000000000000
R10: 00005567752fd980 R11: 0000000000000246 R12: 00000000000001ed
R13: 00007ffdd3b9ffe0 R14: 0000000000000000 R15: 0000000000000000


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