BUG: unable to handle kernel paging request in dquot_add_space

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a1b977b4 Linux 4.19.150
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1350e078500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c14008c8da1ca4d4
dashboard link: https://syzkaller.appspot.com/bug?extid=1ecc80de272807704eff
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1092474f900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11590a8b900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1ecc80...@syzkaller.appspotmail.com

audit: type=1400 audit(1602565026.353:8): avc: denied { execmem } for pid=6501 comm="syz-executor986" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue
Quota error (device loop0): qtree_write_dquot: Error -927940090 occurred while creating quota
BUG: unable to handle kernel paging request at fffffbfff9161860
PGD 21ffed067 P4D 21ffed067 PUD 21ffec067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 6501 Comm: syz-executor986 Not tainted 4.19.150-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:dquot_add_space+0x45/0x1130 fs/quota/dquot.c:1307
Code: 4c 24 3c 4c 89 44 24 28 e8 e8 c8 9e ff 48 8d 83 00 01 00 00 48 89 c2 48 89 44 24 30 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 8a 0d 00 00 4c 8d bb c0 00 00 00 4c 8b b3 00 01
RSP: 0018:ffff8880897c7190 EFLAGS: 00010a07
RAX: dffffc0000000000 RBX: ffffffffc8b0c206 RCX: 0000000000000001
RDX: 1ffffffff9161860 RSI: ffffffff81d30978 RDI: ffffffffc8b0c206
RBP: ffff8880808053f0 R08: ffff8880897c72a0 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000001 R12: ffff888080805990
R13: 0000000000000000 R14: ffffffffc8b0c206 R15: ffff8880897c72a0
FS: 0000000000aac880(0000) GS:ffff8880ae200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff9161860 CR3: 0000000092be2000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__dquot_alloc_space+0x44f/0x780 fs/quota/dquot.c:1672
dquot_alloc_space_nodirty include/linux/quotaops.h:298 [inline]
dquot_alloc_space include/linux/quotaops.h:311 [inline]
dquot_alloc_block include/linux/quotaops.h:335 [inline]
ext4_mb_new_blocks+0x1ae2/0x43e0 fs/ext4/mballoc.c:4533
ext4_new_meta_blocks+0x2fe/0x360 fs/ext4/balloc.c:665
ext4_xattr_block_set+0x12ea/0x2ee0 fs/ext4/xattr.c:2075
ext4_xattr_set_handle+0x9b9/0xf90 fs/ext4/xattr.c:2411
ext4_xattr_set+0x135/0x2a0 fs/ext4/xattr.c:2511
__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+0xf9/0x670 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x444709
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:00007ffdc08bc818 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 0000000000444709
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000020000040
RBP: 00000000006cf018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004022f0
R13: 0000000000402380 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: fffffbfff9161860
---[ end trace 5b65117170869d36 ]---
RIP: 0010:dquot_add_space+0x45/0x1130 fs/quota/dquot.c:1307
Code: 4c 24 3c 4c 89 44 24 28 e8 e8 c8 9e ff 48 8d 83 00 01 00 00 48 89 c2 48 89 44 24 30 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 8a 0d 00 00 4c 8d bb c0 00 00 00 4c 8b b3 00 01
RSP: 0018:ffff8880897c7190 EFLAGS: 00010a07
RAX: dffffc0000000000 RBX: ffffffffc8b0c206 RCX: 0000000000000001
RDX: 1ffffffff9161860 RSI: ffffffff81d30978 RDI: ffffffffc8b0c206
RBP: ffff8880808053f0 R08: ffff8880897c72a0 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000001 R12: ffff888080805990
R13: 0000000000000000 R14: ffffffffc8b0c206 R15: ffff8880897c72a0
FS: 0000000000aac880(0000) GS:ffff8880ae200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff9161860 CR3: 0000000092be2000 CR4: 00000000001406f0
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=141c37db500000
start commit: a1b977b4 Linux 4.19.150
git tree: linux-4.19.y

kernel config: https://syzkaller.appspot.com/x/.config?x=c14008c8da1ca4d4
dashboard link: https://syzkaller.appspot.com/bug?extid=1ecc80de272807704eff

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1092474f900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11590a8b900000

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