KCSAN: data-race in ext4_file_write_iter / ext4_handle_inode

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_file_write_iter / ext4_handle_inode_extension (2) ext4	6				2	1797d	1801d	0/29	auto-closed as invalid on 2020/09/18 14:01

================================================================== BUG: KCSAN: data-race in ext4_file_write_iter / ext4_handle_inode_extension write to 0xffff8881250e3438 of 8 bytes by task 17737 on cpu 0: i_size_write include/linux/fs.h:888 [inline] ext4_update_inode_size fs/ext4/ext4.h:3042 [inline] ext4_handle_inode_extension+0x3d3/0x5b0 fs/ext4/file.c:330 ext4_dio_write_iter fs/ext4/file.c:536 [inline] ext4_file_write_iter+0x849/0xd70 fs/ext4/file.c:640 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693 do_iter_write fs/read_write.c:998 [inline] do_iter_write+0x13b/0x3c0 fs/read_write.c:979 vfs_iter_write+0x5c/0x80 fs/read_write.c:1039 iter_file_splice_write+0x536/0x850 fs/splice.c:760 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0xa0/0xc0 fs/splice.c:1037 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992 do_splice_direct+0x161/0x1e0 fs/splice.c:1080 do_sendfile+0x384/0x7f0 fs/read_write.c:1520 __do_sys_sendfile64 fs/read_write.c:1581 [inline] __se_sys_sendfile64 fs/read_write.c:1567 [inline] __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1567 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8881250e3438 of 8 bytes by task 17741 on cpu 1: ext4_dio_write_iter fs/ext4/file.c:467 [inline] ext4_file_write_iter+0x1fa/0xd70 fs/ext4/file.c:640 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693 do_iter_write fs/read_write.c:998 [inline] do_iter_write+0x13b/0x3c0 fs/read_write.c:979 vfs_iter_write+0x5c/0x80 fs/read_write.c:1039 iter_file_splice_write+0x536/0x850 fs/splice.c:760 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0xa0/0xc0 fs/splice.c:1037 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992 do_splice_direct+0x161/0x1e0 fs/splice.c:1080 do_sendfile+0x384/0x7f0 fs/read_write.c:1520 __do_sys_sendfile64 fs/read_write.c:1581 [inline] __se_sys_sendfile64 fs/read_write.c:1567 [inline] __x64_sys_sendfile64+0x12a/0x140 fs/read_write.c:1567 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17741 Comm: syz-executor.0 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================