EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: writeback.
==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / ext4_sync_file

write to 0xffff8881075fb258 of 8 bytes by task 25789 on cpu 0:
 __mark_inode_dirty+0x21f/0x6b0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/fs-writeback.c:2293
 mark_buffer_dirty+0x143/0x230 syzkaller/managers/upstream-kcsan-gce/kernel/fs/buffer.c:1141
 __block_commit_write syzkaller/managers/upstream-kcsan-gce/kernel/fs/buffer.c:2084 [inline]
 block_write_end+0x13d/0x230 syzkaller/managers/upstream-kcsan-gce/kernel/fs/buffer.c:2162
 ext4_write_end+0x19e/0xa00 syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/inode.c:1300
 ext4_da_write_end+0x93/0x760 syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/inode.c:3080
 generic_perform_write+0x23e/0x3a0 syzkaller/managers/upstream-kcsan-gce/kernel/mm/filemap.c:3423
 ext4_buffered_write_iter+0x2e5/0x3e0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/file.c:270
 ext4_file_write_iter+0x47a/0x1060 syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/file.c:503
 call_write_iter syzkaller/managers/upstream-kcsan-gce/kernel/./include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:740
 do_iter_write+0x112/0x4c0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:907
 iter_file_splice_write+0x41a/0x770 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:686
 do_splice_from syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:888
 do_splice_direct+0xf5/0x170 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:976
 do_sendfile+0x5e0/0xcf0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1257
 __do_sys_sendfile64 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1304
 do_syscall_64+0x39/0x80 syzkaller/managers/upstream-kcsan-gce/kernel/arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881075fb258 of 8 bytes by task 25781 on cpu 1:
 ext4_fsync_nojournal syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/fsync.c:87 [inline]
 ext4_sync_file+0x294/0x6e0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 syzkaller/managers/upstream-kcsan-gce/kernel/fs/sync.c:200
 generic_write_sync syzkaller/managers/upstream-kcsan-gce/kernel/./include/linux/fs.h:2737 [inline]
 ext4_buffered_write_iter+0x38f/0x3e0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/file.c:278
 ext4_file_write_iter+0x47a/0x1060 syzkaller/managers/upstream-kcsan-gce/kernel/fs/ext4/file.c:503
 call_write_iter syzkaller/managers/upstream-kcsan-gce/kernel/./include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:740
 do_iter_write+0x112/0x4c0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:907
 iter_file_splice_write+0x41a/0x770 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:686
 do_splice_from syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:888
 do_splice_direct+0xf5/0x170 syzkaller/managers/upstream-kcsan-gce/kernel/fs/splice.c:976
 do_sendfile+0x5e0/0xcf0 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1257
 __do_sys_sendfile64 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 syzkaller/managers/upstream-kcsan-gce/kernel/fs/read_write.c:1304
 do_syscall_64+0x39/0x80 syzkaller/managers/upstream-kcsan-gce/kernel/arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25781 Comm: syz-executor.0 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================