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KCSAN: data-race in ksys_read / ksys_write

Status: auto-closed as invalid on 2020/02/07 14:57
Subsystems: fs
[Documentation on labels]
First crash: 1639d, last: 1602d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ksys_read / ksys_write (3) fs 1 645d 645d 0/26 auto-closed as invalid on 2022/08/18 02:32
upstream KCSAN: data-race in ksys_read / ksys_write (2) fs 1 1338d 1338d 0/26 auto-closed as invalid on 2020/09/24 13:26

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ksys_read / ksys_write

read to 0xffff888122e8bb68 of 8 bytes by task 7616 on cpu 1:
 ksys_read+0xa9/0x1b0 fs/read_write.c:584
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff888122e8bb68 of 8 bytes by task 10046 on cpu 0:
 ksys_write+0x101/0x1b0 fs/read_write.c:613
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10046 Comm: syz-fuzzer Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 10046 Comm: syz-fuzzer Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x11d/0x181 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xd kernel/kcsan/report.c:315
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:423
 check_access kernel/kcsan/core.c:466 [inline]
 __tsan_write8 kernel/kcsan/core.c:596 [inline]
 __tsan_unaligned_write8+0xc4/0x100 kernel/kcsan/core.c:596
 ksys_write+0x101/0x1b0 fs/read_write.c:613
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x47c530
Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
RSP: 002b:000000c4319f3548 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530
RDX: 0000000000000004 RSI: 000000c4202d8200 RDI: 0000000000000003
RBP: 000000c4319f35a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 000000c4200c3b00
R13: 000000000000007f R14: 0000000000c21de0 R15: ffffffffffffc79f
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/11/29 14:52 https://github.com/google/ktsan.git kcsan ef798c30ba4e 4f7e1d0f .config console log report ci2-upstream-kcsan-gce
2019/11/22 15:58 https://github.com/google/ktsan.git kcsan 5863cc791e4c 598ca6c8 .config console log report ci2-upstream-kcsan-gce
2019/11/12 09:50 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config console log report ci2-upstream-kcsan-gce
2019/11/10 02:08 https://github.com/google/ktsan.git kcsan 94c006602e13 dc438b91 .config console log report ci2-upstream-kcsan-gce
2019/11/04 17:31 https://github.com/google/ktsan.git kcsan 94c006602e13 18e12644 .config console log report ci2-upstream-kcsan-gce
2019/11/03 11:25 https://github.com/google/ktsan.git kcsan 05f2236801fe c9610487 .config console log report ci2-upstream-kcsan-gce
2019/11/01 20:58 https://github.com/google/ktsan.git kcsan 05f2236801fe 997ccc67 .config console log report ci2-upstream-kcsan-gce
2019/10/23 15:54 https://github.com/google/ktsan.git kcsan 05f2236801fe b602d64b .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.