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

write to 0xffff8880b4583582 of 2 bytes by task 16114 on cpu 0:
 vfs_readlink+0x20b/0x260 fs/namei.c:4545
 do_readlinkat+0x170/0x200 fs/stat.c:431
 __do_sys_readlinkat fs/stat.c:446 [inline]
 __se_sys_readlinkat fs/stat.c:443 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:443
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b4583582 of 2 bytes by task 16102 on cpu 1:
 vfs_readlink+0x56/0x260 fs/namei.c:4537
 do_readlinkat+0x170/0x200 fs/stat.c:431
 __do_sys_readlinkat fs/stat.c:446 [inline]
 __se_sys_readlinkat fs/stat.c:443 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:443
 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: 1 PID: 16102 Comm: systemd-udevd Not tainted 5.9.0-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: 16102 Comm: systemd-udevd Not tainted 5.9.0-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+0x10f/0x19d lib/dump_stack.c:118
 panic+0x207/0x64a kernel/panic.c:231
 kcsan_report+0x684/0x690 kernel/kcsan/report.c:630
 kcsan_setup_watchpoint+0x41e/0x4a0 kernel/kcsan/core.c:540
 vfs_readlink+0x56/0x260 fs/namei.c:4537
 do_readlinkat+0x170/0x200 fs/stat.c:431
 __do_sys_readlinkat fs/stat.c:446 [inline]
 __se_sys_readlinkat fs/stat.c:443 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:443
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f4ae86960ba
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:00007ffe88f79a88 EFLAGS: 00000202 ORIG_RAX: 000000000000010b
RAX: ffffffffffffffda RBX: 0000559f0f5433d0 RCX: 00007f4ae86960ba
RDX: 0000559f0f5433d0 RSI: 00007ffe88f79b10 RDI: 00000000ffffff9c
RBP: 0000000000000064 R08: 0000000000002508 R09: 0000000000000070
R10: 0000000000000063 R11: 0000000000000202 R12: 00007ffe88f79b10
R13: 00000000ffffff9c R14: 00007ffe88f79ae0 R15: 0000000000000063
Kernel Offset: disabled
Rebooting in 86400 seconds..