==================================================================
BUG: KCSAN: data-race in userfaultfd_ioctl / userfaultfd_ioctl
write to 0xffff888098914c70 of 4 bytes by task 29215 on cpu 0:
userfaultfd_api fs/userfaultfd.c:1850 [inline]
userfaultfd_ioctl+0x1829/0x2560 fs/userfaultfd.c:1874
vfs_ioctl fs/ioctl.c:47 [inline]
ksys_ioctl+0x101/0x150 fs/ioctl.c:763
__do_sys_ioctl fs/ioctl.c:772 [inline]
__se_sys_ioctl fs/ioctl.c:770 [inline]
__x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffff888098914c70 of 4 bytes by task 29220 on cpu 1:
userfaultfd_ioctl+0x6d/0x2560 fs/userfaultfd.c:1869
vfs_ioctl fs/ioctl.c:47 [inline]
ksys_ioctl+0x101/0x150 fs/ioctl.c:763
__do_sys_ioctl fs/ioctl.c:772 [inline]
__se_sys_ioctl fs/ioctl.c:770 [inline]
__x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29220 Comm: syz-executor.2 Not tainted 5.6.0-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: 29220 Comm: syz-executor.2 Not tainted 5.6.0-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/0x187 lib/dump_stack.c:118
panic+0x210/0x640 kernel/panic.c:221
kcsan_report.cold+0xc/0x14 kernel/kcsan/report.c:556
kcsan_setup_watchpoint+0x304/0x400 kernel/kcsan/core.c:495
userfaultfd_ioctl+0x6d/0x2560 fs/userfaultfd.c:1869
vfs_ioctl fs/ioctl.c:47 [inline]
ksys_ioctl+0x101/0x150 fs/ioctl.c:763
__do_sys_ioctl fs/ioctl.c:772 [inline]
__se_sys_ioctl fs/ioctl.c:770 [inline]
__x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c479
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:00007fe06de55c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe06de566d4 RCX: 000000000045c479
RDX: 0000000020000200 RSI: 00000000c020aa00 RDI: 0000000000000003
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000005b4 R14: 00000000004c8126 R15: 000000000076bfcc
Kernel Offset: disabled
Rebooting in 86400 seconds..