syzbot

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BUG: KCSAN: data-race in kernfs_iop_permission / kernfs_iop_permission

write to 0xffff8881006c2070 of 4 bytes by task 20072 on cpu 1:
 inode_set_atime_to_ts include/linux/fs.h:1805 [inline]
 set_inode_attr fs/kernfs/inode.c:163 [inline]
 kernfs_refresh_inode fs/kernfs/inode.c:179 [inline]
 kernfs_iop_permission+0x12b/0x220 fs/kernfs/inode.c:290
 do_inode_permission fs/namei.c:526 [inline]
 inode_permission+0x1ca/0x310 fs/namei.c:593
 may_lookup fs/namei.c:1873 [inline]
 link_path_walk+0x63c/0x900 fs/namei.c:2467
 path_parentat fs/namei.c:2723 [inline]
 __filename_parentat+0x15c/0x3f0 fs/namei.c:2747
 filename_parentat fs/namei.c:2765 [inline]
 do_unlinkat+0x99/0x480 fs/namei.c:4712
 __do_sys_unlink fs/namei.c:4783 [inline]
 __se_sys_unlink fs/namei.c:4781 [inline]
 __x64_sys_unlink+0x2e/0x40 fs/namei.c:4781
 x64_sys_call+0x2dcf/0x3000 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff8881006c2070 of 4 bytes by task 13947 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1805 [inline]
 set_inode_attr fs/kernfs/inode.c:163 [inline]
 kernfs_refresh_inode fs/kernfs/inode.c:179 [inline]
 kernfs_iop_permission+0x12b/0x220 fs/kernfs/inode.c:290
 do_inode_permission fs/namei.c:526 [inline]
 inode_permission+0x1ca/0x310 fs/namei.c:593
 may_lookup fs/namei.c:1873 [inline]
 link_path_walk+0x63c/0x900 fs/namei.c:2467
 path_lookupat+0x63/0x2a0 fs/namei.c:2675
 filename_lookup+0x147/0x340 fs/namei.c:2705
 user_path_at+0x3e/0x130 fs/namei.c:3215
 ksys_umount fs/namespace.c:2061 [inline]
 __do_sys_umount fs/namespace.c:2069 [inline]
 __se_sys_umount fs/namespace.c:2067 [inline]
 __x64_sys_umount+0x85/0xe0 fs/namespace.c:2067
 x64_sys_call+0xdd2/0x3000 arch/x86/include/generated/asm/syscalls_64.h:167
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x32f93ca6 -> 0x08a77da5

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 13947 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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