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KCSAN: data-race in n_tty_receive_char / n_tty_write (3)

Status: auto-obsoleted due to no activity on 2023/03/30 21:01
Subsystems: serial
[Documentation on labels]
First crash: 465d, last: 424d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (4) serial 1 365d 365d 0/26 auto-obsoleted due to no activity on 2023/05/20 17:17
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (6) serial 27 21d 129d 0/26 moderation: reported on 2023/12/07 10:05
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (2) serial 13 512d 653d 0/26 auto-obsoleted due to no activity on 2022/12/30 17:18
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write serial 25 689d 952d 0/26 auto-closed as invalid on 2022/06/30 23:55
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (5) serial 3 290d 314d 0/26 auto-obsoleted due to no activity on 2023/08/03 17:30

Sample crash report:
==================================================================
BUG: KCSAN: data-race in n_tty_receive_char / n_tty_write

write to 0xffffc900008d3028 of 8 bytes by task 17801 on cpu 1:
 commit_echoes drivers/tty/n_tty.c:768 [inline]
 n_tty_receive_char+0x4be/0x670 drivers/tty/n_tty.c:1420
 n_tty_receive_buf_standard+0x484/0x2d40 drivers/tty/n_tty.c:1589
 __receive_buf drivers/tty/n_tty.c:1613 [inline]
 n_tty_receive_buf_common+0x84a/0xb50 drivers/tty/n_tty.c:1711
 n_tty_receive_buf2+0x32/0x40 drivers/tty/n_tty.c:1746
 tty_ldisc_receive_buf+0x60/0xe0 drivers/tty/tty_buffer.c:457
 tty_port_default_receive_buf+0x58/0x80 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:515 [inline]
 flush_to_ldisc+0x1ca/0x400 drivers/tty/tty_buffer.c:565
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2289
 worker_thread+0x5ef/0xa10 kernel/workqueue.c:2436
 kthread+0x1ac/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffffc900008d3028 of 8 bytes by task 3573 on cpu 0:
 process_echoes drivers/tty/n_tty.c:794 [inline]
 n_tty_write+0x156/0xa80 drivers/tty/n_tty.c:2336
 do_tty_write drivers/tty/tty_io.c:1018 [inline]
 file_tty_write+0x3a0/0x600 drivers/tty/tty_io.c:1089
 tty_write+0x28/0x30 drivers/tty/tty_io.c:1110
 call_write_iter include/linux/fs.h:2189 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x45a/0x750 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000004 -> 0x0000000000000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3573 Comm: syz-executor.1 Not tainted 6.2.0-rc8-syzkaller-00021-ge1c04510f521-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/15 23:10 upstream e1c04510f521 6be0f1f5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2023/02/06 20:20 upstream d2d11f342b17 0a9c11b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2023/01/27 11:04 upstream 7c46948a6e9c 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2023/01/09 14:13 upstream 1fe4fd6f5cad 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2023/01/05 20:10 upstream 512dee0c00ad 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
* Struck through repros no longer work on HEAD.