BUG: sleeping function called from invalid context in console

BUG: sleeping function called from invalid context in console_lock (2)
Status: upstream: reported C repro on 2021/06/07 15:46
Reported-by: syzbot+dbac96d8e73b61aa559c@syzkaller.appspotmail.com
First crash: 56d, last: 54d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: BUG: sleeping function called from invalid context in do_con_write (log)
Repro: C syz .config

Fix bisection: the fix commit could be any of (bisect log):
614124bea77e Linux 5.13-rc5
f55966571d5e Merge tag 'drm-next-2021-07-08-1' of git://anongit.freedesktop.org/drm/drm

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	BUG: sleeping function called from invalid context in console_lock				1	441d	440d	0/22	auto-closed as invalid on 2020/09/14 09:18

Sample crash report:

BUG: sleeping function called from invalid context at kernel/printk/printk.c:2460
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 8449, name: syz-executor236
3 locks held by syz-executor236/8449:
 #0: ffff8880202f4098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffff8880202f43f8 (&tty->flow_lock){....}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:379 [inline]
 #1: ffff8880202f43f8 (&tty->flow_lock){....}-{2:2}, at: n_tty_ioctl_helper+0xcc/0x3a0 drivers/tty/tty_ioctl.c:857
 #2: ffff8880202f4098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:288
irq event stamp: 1246
hardirqs last  enabled at (1245): [<ffffffff81b9f295>] kasan_quarantine_put+0xf5/0x210 mm/kasan/quarantine.c:220
hardirqs last disabled at (1246): [<ffffffff89192651>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline]
hardirqs last disabled at (1246): [<ffffffff89192651>] _raw_spin_lock_irq+0x41/0x50 kernel/locking/spinlock.c:167
softirqs last  enabled at (1098): [<ffffffff8145d336>] invoke_softirq kernel/softirq.c:433 [inline]
softirqs last  enabled at (1098): [<ffffffff8145d336>] __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
softirqs last disabled at (1043): [<ffffffff8145d336>] invoke_softirq kernel/softirq.c:433 [inline]
softirqs last disabled at (1043): [<ffffffff8145d336>] __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 1 PID: 8449 Comm: syz-executor236 Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 ___might_sleep.cold+0x1f1/0x237 kernel/sched/core.c:8338
 console_lock+0x19/0x80 kernel/printk/printk.c:2460
 do_con_write+0x10f/0x1e60 drivers/tty/vt/vt.c:2868
 con_write+0x21/0x40 drivers/tty/vt/vt.c:3255
 n_hdlc_send_frames+0x24b/0x490 drivers/tty/n_hdlc.c:290
 tty_wakeup+0xe1/0x120 drivers/tty/tty_io.c:534
 __start_tty drivers/tty/tty_io.c:822 [inline]
 __start_tty+0x116/0x150 drivers/tty/tty_io.c:815
 n_tty_ioctl_helper+0x348/0x3a0 drivers/tty/tty_ioctl.c:860
 n_hdlc_tty_ioctl+0xe4/0x360 drivers/tty/n_hdlc.c:631
 tty_ioctl+0xef9/0x1600 drivers/tty/tty_io.c:2814
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x440009
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd44ab52f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 0000000000440009
RDX: 0000000000000001 RSI: 000000000000540a RDI: 0000000000000005
RBP: 0000000000000000 R08: 000000000000000d R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403550
R13: 0000000000000000 R14: 00007ffd44ab5320 R15: 00007ffd44ab5310

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kasan-gce	2021/06/07 23:16	upstream	614124bea77e	e59537be	.config	log	report	syz	C		BUG: sleeping function called from invalid context in console_lock
ci-upstream-kasan-gce	2021/06/06 00:29	upstream	e5220dd16778	500c2339	.config	log	report	syz	C		BUG: sleeping function called from invalid context in console_lock
ci-upstream-kasan-gce	2021/06/06 00:10	upstream	e5220dd16778	500c2339	.config	log	report			info	BUG: sleeping function called from invalid context in console_lock