==================================================================
BUG: KCSAN: data-race in ppp_asynctty_receive / tty_set_termios

write to 0xffff888114821521 of 1 bytes by task 13119 on cpu 1:
 unset_locked_termios drivers/tty/tty_ioctl.c:220 [inline]
 tty_set_termios+0x480/0x8b0 drivers/tty/tty_ioctl.c:340
 set_termios+0x497/0x4e0 drivers/tty/tty_ioctl.c:516
 tty_mode_ioctl+0x391/0x5d0
 ppp_asynctty_ioctl+0x21d/0x2e0 drivers/net/ppp/ppp_async.c:324
 tty_ioctl+0x886/0xbe0 drivers/tty/tty_io.c:2812
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0xd3/0x150 fs/ioctl.c:890
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:890
 x64_sys_call+0x155d/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888114821521 of 1 bytes by task 10 on cpu 0:
 ppp_async_input drivers/net/ppp/ppp_async.c:906 [inline]
 ppp_asynctty_receive+0x785/0x1050 drivers/net/ppp/ppp_async.c:342
 tty_ldisc_receive_buf+0xd9/0x100 drivers/tty/tty_buffer.c:391
 tty_port_default_receive_buf+0x59/0x90 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x1ce/0x410 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x11 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10 Comm: kworker/u8:0 Tainted: G        W          6.9.0-rc4-syzkaller-00034-g4b6b51322118 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound flush_to_ldisc
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 10 at kernel/kcov.c:860 kcov_remote_start+0x326/0x380 kernel/kcov.c:860
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/u8:0 Tainted: G        W          6.9.0-rc4-syzkaller-00034-g4b6b51322118 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: nfc2_nci_rx_wq nci_rx_work
RIP: 0010:kcov_remote_start+0x326/0x380 kernel/kcov.c:860
Code: b0 f1 28 00 4c 89 f7 e8 18 5f 2a 00 e9 21 fd ff ff 0f 8d 1b fd ff ff 4c 89 f7 be 03 00 00 00 e8 90 5d 89 00 e9 09 fd ff ff 90 <0f> 0b 90 65 48 8b 05 5f 9d d2 7e 41 f7 c4 00 02 00 00 0f 84 f0 fc
RSP: 0018:ffffc9000005fce8 EFLAGS: 00010002
RAX: 0000000080000000 RBX: 0000000000000003 RCX: 0000000000000002
RDX: 0000000000000baa RSI: 0000000000000003 RDI: 0000000000000003
RBP: 0000000000000003 R08: ffffffff84df8a12 R09: 0000000000000000
R10: 0001ffffffffffff R11: 0001c9000005fcc8 R12: 0000000000000246
R13: ffff888111956000 R14: ffff8881119560d0 R15: ffff888100e32100
FS:  0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1e0c531d58 CR3: 0000000131ef8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 kcov_remote_start_common include/linux/kcov.h:48 [inline]
 nci_rx_work+0x7a/0x230 net/nfc/nci/core.c:1513
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 10 at kernel/kcov.c:860 kcov_remote_start+0x326/0x380 kernel/kcov.c:860
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/u8:0 Tainted: G        W          6.9.0-rc4-syzkaller-00034-g4b6b51322118 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: nfc2_nci_rx_wq nci_rx_work
RIP: 0010:kcov_remote_start+0x326/0x380 kernel/kcov.c:860
Code: b0 f1 28 00 4c 89 f7 e8 18 5f 2a 00 e9 21 fd ff ff 0f 8d 1b fd ff ff 4c 89 f7 be 03 00 00 00 e8 90 5d 89 00 e9 09 fd ff ff 90 <0f> 0b 90 65 48 8b 05 5f 9d d2 7e 41 f7 c4 00 02 00 00 0f 84 f0 fc
RSP: 0018:ffffc9000005fce8 EFLAGS: 00010002
RAX: 0000000080000000 RBX: 0000000000000003 RCX: 0000000000000002
RDX: 0000000000000de8 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 0000000000000003 R08: ffffffff84df8a12 R09: 0000000000000000
R10: 0001ffffffffffff R11: 0001c9000005fcc8 R12: 0000000000000246
R13: ffff888111956000 R14: ffff8881119560d0 R15: ffff888100e32100
FS:  0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83205e2fe0 CR3: 000000010413c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 kcov_remote_start_common include/linux/kcov.h:48 [inline]
 nci_rx_work+0x7a/0x230 net/nfc/nci/core.c:1513
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 1 PID: 10 at kernel/kcov.c:860 kcov_remote_start+0x326/0x380 kernel/kcov.c:860
Modules linked in:
CPU: 1 PID: 10 Comm: kworker/u8:0 Tainted: G        W          6.9.0-rc4-syzkaller-00034-g4b6b51322118 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: nfc2_nci_rx_wq nci_rx_work
RIP: 0010:kcov_remote_start+0x326/0x380 kernel/kcov.c:860
Code: b0 f1 28 00 4c 89 f7 e8 18 5f 2a 00 e9 21 fd ff ff 0f 8d 1b fd ff ff 4c 89 f7 be 03 00 00 00 e8 90 5d 89 00 e9 09 fd ff ff 90 <0f> 0b 90 65 48 8b 05 5f 9d d2 7e 41 f7 c4 00 02 00 00 0f 84 f0 fc
RSP: 0018:ffffc9000005fce8 EFLAGS: 00010002
RAX: 0000000080000000 RBX: 0000000000000003 RCX: 0000000000000002
RDX: 0000000000000097 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 0000000000000003 R08: ffffffff84df8a12 R09: 0000000000000000
R10: 0001ffffffffffff R11: 0001c9000005fcc8 R12: 0000000000000246
R13: ffff888111956000 R14: ffff8881119560d0 R15: ffff888100e32100
FS:  0000000000000000(0000) GS:ffff888237d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2cf25000 CR3: 0000000131ef8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kcov_remote_start_common include/linux/kcov.h:48 [inline]
 nci_rx_work+0x7a/0x230 net/nfc/nci/core.c:1513
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
---[ end trace 0000000000000000 ]---