syzbot

==================================================================
BUG: KCSAN: data-race in ext4_remount / inode_permission

write to 0xffff8881026dc050 of 8 bytes by task 7633 on cpu 1:
 ext4_remount+0x3ca/0x1840 fs/ext4/super.c:5891
 legacy_reconfigure+0x8e/0xa0 fs/fs_context.c:615
 reconfigure_super+0x2d3/0x4f0 fs/super.c:906
 do_remount fs/namespace.c:2639 [inline]
 path_mount+0x1442/0x1ce0 fs/namespace.c:3227
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3433
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3433
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881026dc050 of 8 bytes by task 7637 on cpu 0:
 sb_rdonly include/linux/fs.h:2221 [inline]
 sb_permission fs/namei.c:470 [inline]
 inode_permission+0xb6/0x290 fs/namei.c:493
 may_create fs/namei.c:2835 [inline]
 vfs_symlink+0x17c/0x300 fs/namei.c:4160
 do_symlinkat+0xeb/0x280 fs/namei.c:4202
 __do_sys_symlink fs/namei.c:4223 [inline]
 __se_sys_symlink fs/namei.c:4221 [inline]
 __x64_sys_symlink+0x32/0x40 fs/namei.c:4221
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7637 Comm: syz-executor.1 Not tainted 5.13.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================