==================================================================
BUG: KCSAN: data-race in vfs_readlink / vfs_readlink

read-write to 0xffff88800bde8a42 of 2 bytes by task 12623 on cpu 1:
 vfs_readlink+0x203/0x250 fs/namei.c:4546
 do_readlinkat+0x170/0x200 fs/stat.c:419
 __do_sys_readlinkat fs/stat.c:434 [inline]
 __se_sys_readlinkat fs/stat.c:431 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:431
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88800bde8a42 of 2 bytes by task 12615 on cpu 0:
 vfs_readlink+0x56/0x250 fs/namei.c:4538
 do_readlinkat+0x170/0x200 fs/stat.c:419
 __do_sys_readlinkat fs/stat.c:434 [inline]
 __se_sys_readlinkat fs/stat.c:431 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:431
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12615 Comm: systemd-udevd Not tainted 5.10.0-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: 0 PID: 12615 Comm: systemd-udevd Not tainted 5.10.0-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+0x116/0x15d lib/dump_stack.c:118
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x46a/0x4d0 kernel/kcsan/core.c:568
 vfs_readlink+0x56/0x250 fs/namei.c:4538
 do_readlinkat+0x170/0x200 fs/stat.c:419
 __do_sys_readlinkat fs/stat.c:434 [inline]
 __se_sys_readlinkat fs/stat.c:431 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:431
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f685abdb0ba
Code: 48 8b 0d e1 bd 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 0b 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ae bd 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe51b07248 EFLAGS: 00000206 ORIG_RAX: 000000000000010b
RAX: ffffffffffffffda RBX: 0000557650d6b650 RCX: 00007f685abdb0ba
RDX: 0000557650d6b650 RSI: 00007ffe51b072d0 RDI: 00000000ffffff9c
RBP: 0000000000000064 R08: 000000000000c081 R09: 0000000000000070
R10: 0000000000000063 R11: 0000000000000206 R12: 00007ffe51b072d0
R13: 00000000ffffff9c R14: 00007ffe51b072a0 R15: 0000000000000063
Kernel Offset: disabled
Rebooting in 86400 seconds..