bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67
building syzkaller on 8516f6d3332fc21083e2adae55114a022fcc2b9b
testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 with gcc (GCC) 8.1.0
kernel signature: 3119de230ac25aa10a797c0953627bbf9b5f4b9ba06290f7373268192277ed13
all runs: crashed: BUG: unable to handle kernel paging request in dquot_add_space
testing current HEAD 2b79150141611d3c6e1b55d4e70f49602482f0b8
testing commit 2b79150141611d3c6e1b55d4e70f49602482f0b8 with gcc (GCC) 8.1.0
kernel signature: 189a78bdbeb264fff821aae0fb813162056ecb5bb94b63e517c3ba49caf70903
all runs: crashed: BUG: unable to handle kernel paging request in dquot_add_space
revisions tested: 2, total time: 22m39.682368463s (build: 16m13.043809039s, test: 5m51.463874912s)
the crash still happens on HEAD
commit msg: Linux 4.14.203
crash: BUG: unable to handle kernel paging request in dquot_add_space
EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue
IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
Quota error (device loop2): qtree_write_dquot: Error -927940090 occurred while creating quota
BUG: unable to handle kernel paging request at fffffbfff9161860
IP: dquot_add_space+0x34/0x1240 fs/quota/dquot.c:1303
ieee80211 phy11: mac80211_hwsim_bss_info_changed(changed=0x10 vif->addr=02:00:00:00:0b:00)
PGD 23ffec067 P4D 23ffec067 PUD 23ffeb067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 8067 Comm: syz-executor.2 Not tainted 4.14.203-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888099248340 task.stack: ffff888098820000
RIP: 0010:dquot_add_space+0x34/0x1240 fs/quota/dquot.c:1303
RSP: 0018:ffff888098827180 EFLAGS: 00010a07
RAX: dffffc0000000000 RBX: ffffffffc8b0c206 RCX: 0000000000000001
RDX: 1ffffffff9161860 RSI: 0000000000000400 RDI: ffffffffc8b0c206
RBP: ffff888098827200 R08: ffff888098827270 R09: 0000000000000002
R10: 0000000000000000 R11: ffff888098827270 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888088cf9f18 R15: 0000000000000400
FS:  00007f600ea95700(0000) GS:ffff8880ba900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff9161860 CR3: 0000000099bed000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
ieee80211 phy11:   HT: op_mode=0xb
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __dquot_alloc_space+0x3d7/0x6d0 fs/quota/dquot.c:1668
 dquot_alloc_space_nodirty include/linux/quotaops.h:295 [inline]
 dquot_alloc_space include/linux/quotaops.h:308 [inline]
 dquot_alloc_block include/linux/quotaops.h:332 [inline]
 ext4_mb_new_blocks+0x420/0x36d0 fs/ext4/mballoc.c:4561
 ext4_new_meta_blocks+0x1be/0x350 fs/ext4/balloc.c:677
 ext4_xattr_block_set+0x1066/0x2c20 fs/ext4/xattr.c:2074
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
 ext4_xattr_set_handle+0x83e/0xc40 fs/ext4/xattr.c:2410
 ext4_xattr_set+0x1b4/0x2e0 fs/ext4/xattr.c:2510
ieee80211 phy12: mac80211_hwsim_bss_info_changed(changed=0x10 vif->addr=02:00:00:00:0c:00)
 ext4_xattr_trusted_set+0x1e/0x20 fs/ext4/xattr_trusted.c:37
 __vfs_setxattr+0xd1/0x130 fs/xattr.c:150
 __vfs_setxattr_noperm+0xe9/0x380 fs/xattr.c:181
 __vfs_setxattr_locked+0x182/0x200 fs/xattr.c:239
 vfs_setxattr+0xf5/0x260 fs/xattr.c:256
ieee80211 phy12:   HT: op_mode=0xb
 setxattr+0x1a0/0x250 fs/xattr.c:523
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
 path_setxattr+0x130/0x150 fs/xattr.c:542
 SYSC_setxattr fs/xattr.c:557 [inline]
 SyS_setxattr+0xf/0x20 fs/xattr.c:553
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45dd99
RSP: 002b:00007f600ea94c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00000000000329c0 RCX: 000000000045dd99
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000020000040
RBP: 000000000118bf70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
R13: 00007ffcba80d69f R14: 00007f600ea959c0 R15: 000000000118bf2c
Code: 89 e5 41 57 41 56 41 55 41 54 53 48 89 fb 48 83 ec 58 48 89 55 c8 48 89 c2 48 89 45 b8 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df <80> 3c 02 
ieee80211 phy13: Selected rate control algorithm 'minstrel_ht'
00 48 89 75 d0 89 4d b0 4c 89 45 c0 0f 85 24 0b 00 00 
RIP: dquot_add_space+0x34/0x1240 fs/quota/dquot.c:1303 RSP: ffff888098827180
CR2: fffffbfff9161860
---[ end trace df45dd07db3648bb ]---