general protection fault in dqput

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 13d2ce42 Linux 4.19.163
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13370f9b500000
kernel config: https://syzkaller.appspot.com/x/.config?x=fac7c3360835a4e0
dashboard link: https://syzkaller.appspot.com/bug?extid=c914f02468af7591b8b6
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10a83e0f500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15e1d487500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c914f0...@syzkaller.appspotmail.com

Quota error (device loop0): qtree_write_dquot: Error -2041447053 occurred while creating quota
Quota error (device loop0): dq_insert_tree: Quota tree root isn't allocated!
Quota error (device loop0): qtree_write_dquot: Error -5 occurred while creating quota
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 8113 Comm: syz-executor229 Not tainted 4.19.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:dqput.part.0+0x1e5/0x830 fs/quota/dquot.c:779
Code: 83 00 01 00 00 48 89 44 24 08 48 c1 e8 03 80 3c 28 00 0f 85 f6 04 00 00 4c 8b bb 00 01 00 00 49 8d 7f 38 48 89 fa 48 c1 ea 03 <80> 3c 2a 00 0f 85 f6 04 00 00 4d 8b 7f 38 4c 89 fa 48 c1 ea 03 80
RSP: 0018:ffff88808cbaf7c0 EFLAGS: 00010a02
RAX: 1ffffffff0ca3fce RBX: ffffffff8651fd73 RCX: 0000000000000000
RDX: 1d0e4ebb70bf6261 RSI: 0000000000000004 RDI: e87275db85fb130b
RBP: dffffc0000000000 R08: 0000000000000000 R09: fffffbfff13c2500
R10: ffffffff89e12803 R11: 0000000000000000 R12: ffffffff8651fe6b
R13: 0000000000000006 R14: fffffbfff0ca3fcd R15: e87275db85fb12d3
FS: 0000000000ad1880(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055644ee5a510 CR3: 00000000a5f84000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
dqput fs/quota/dquot.c:752 [inline]
dqput_all fs/quota/dquot.c:391 [inline]
__dquot_initialize+0x5ad/0xb70 fs/quota/dquot.c:1521
ext4_xattr_set+0xbd/0x2a0 fs/ext4/xattr.c:2495
__vfs_setxattr+0x10e/0x170 fs/xattr.c:149
__vfs_setxattr_noperm+0x11a/0x420 fs/xattr.c:180
__vfs_setxattr_locked+0x176/0x250 fs/xattr.c:238
vfs_setxattr+0xe5/0x270 fs/xattr.c:255
setxattr+0x23d/0x330 fs/xattr.c:520
path_setxattr+0x170/0x190 fs/xattr.c:539
__do_sys_setxattr fs/xattr.c:554 [inline]
__se_sys_setxattr fs/xattr.c:550 [inline]
__x64_sys_setxattr+0xc0/0x160 fs/xattr.c:550
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4448a9
Code: 8d d7 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 5b d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd1da8c108 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00000000004448a9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000020000040
RBP: 00000000006cf018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402490
R13: 0000000000402520 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace b9fa8f9c97ba89a0 ]---
RIP: 0010:dqput.part.0+0x1e5/0x830 fs/quota/dquot.c:779
Code: 83 00 01 00 00 48 89 44 24 08 48 c1 e8 03 80 3c 28 00 0f 85 f6 04 00 00 4c 8b bb 00 01 00 00 49 8d 7f 38 48 89 fa 48 c1 ea 03 <80> 3c 2a 00 0f 85 f6 04 00 00 4d 8b 7f 38 4c 89 fa 48 c1 ea 03 80
RSP: 0018:ffff88808cbaf7c0 EFLAGS: 00010a02
RAX: 1ffffffff0ca3fce RBX: ffffffff8651fd73 RCX: 0000000000000000
RDX: 1d0e4ebb70bf6261 RSI: 0000000000000004 RDI: e87275db85fb130b
RBP: dffffc0000000000 R08: 0000000000000000 R09: fffffbfff13c2500
R10: ffffffff89e12803 R11: 0000000000000000 R12: ffffffff8651fe6b
R13: 0000000000000006 R14: fffffbfff0ca3fcd R15: e87275db85fb12d3
FS: 0000000000ad1880(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feec803a048 CR3: 00000000a5f84000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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[syzbot]

syzbot suspects this issue was fixed by commit:

commit 7bae84821b47e2ffa87a7afcb6891dd7e61c65ef
Author: Jan Kara <ja...@suse.cz>
Date: Mon Nov 2 15:16:29 2020 +0000

quota: Sanity-check quota file headers on load

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1548e11b500000
start commit: 13d2ce42 Linux 4.19.163
git tree: linux-4.19.y

kernel config: https://syzkaller.appspot.com/x/.config?x=fac7c3360835a4e0
dashboard link: https://syzkaller.appspot.com/bug?extid=c914f02468af7591b8b6

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1789db8f500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14fd4d83500000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: quota: Sanity-check quota file headers on load

For information about bisection process see: https://goo.gl/tpsmEJ#bisection