================================================================== BUG: KCSAN: data-race in do_sendfile / ksys_write write to 0xffff88812143bd68 of 8 bytes by task 31515 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/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88812143bd68 of 8 bytes by task 31522 on cpu 1: do_sendfile+0x299/0x7f0 fs/read_write.c:1437 __do_sys_sendfile64 fs/read_write.c:1519 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0xbe/0x140 fs/read_write.c:1511 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 31522 Comm: syz-executor.3 Not tainted 5.5.0-rc1-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: 1 PID: 31522 Comm: syz-executor.3 Not tainted 5.5.0-rc1-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:313 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:416 check_access kernel/kcsan/core.c:459 [inline] __tsan_read8+0xc6/0x100 kernel/kcsan/core.c:589 do_sendfile+0x299/0x7f0 fs/read_write.c:1437 __do_sys_sendfile64 fs/read_write.c:1519 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0xbe/0x140 fs/read_write.c:1511 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45a919 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f77e879dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a919 RDX: 0000000020001000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000ffff R11: 0000000000000246 R12: 00007f77e879e6d4 R13: 00000000004c925e R14: 00000000004e0f88 R15: 00000000ffffffff Kernel Offset: disabled Rebooting in 86400 seconds..