================================================================== BUG: KCSAN: data-race in ext4_ext_insert_extent / ext4_mark_iloc_dirty write to 0xffff88813904aa6a of 2 bytes by task 346 on cpu 1: ext4_ext_store_pblock fs/ext4/ext4_extents.h:256 [inline] ext4_ext_insert_extent+0x1242/0x2bc0 fs/ext4/extents.c:2116 ext4_ext_map_blocks+0x1597/0x1fd0 fs/ext4/extents.c:4259 ext4_map_blocks+0x726/0xff0 fs/ext4/inode.c:638 mpage_map_one_extent+0x10d/0x3a0 fs/ext4/inode.c:2397 mpage_map_and_submit_extent fs/ext4/inode.c:2450 [inline] ext4_writepages+0xa51/0x1e70 fs/ext4/inode.c:2802 do_writepages+0x7b/0x150 mm/page-writeback.c:2352 __writeback_single_inode+0x80/0x4d0 fs/fs-writeback.c:1467 writeback_sb_inodes+0x6a7/0xff0 fs/fs-writeback.c:1732 wb_writeback+0x27d/0x660 fs/fs-writeback.c:1905 wb_do_writeback+0x101/0x5d0 fs/fs-writeback.c:2050 wb_workfn+0xc8/0x430 fs/fs-writeback.c:2091 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275 worker_thread+0x616/0xa70 kernel/workqueue.c:2421 kthread+0x20b/0x230 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 read to 0xffff88813904aa68 of 4 bytes by task 24883 on cpu 0: ext4_do_update_inode fs/ext4/inode.c:5111 [inline] ext4_mark_iloc_dirty+0xda1/0x1700 fs/ext4/inode.c:5726 __ext4_mark_inode_dirty+0x4db/0x5e0 fs/ext4/inode.c:5920 ext4_dirty_inode+0x86/0xa0 fs/ext4/inode.c:5949 __mark_inode_dirty+0x72/0x6f0 fs/fs-writeback.c:2274 mark_inode_dirty include/linux/fs.h:2267 [inline] generic_write_end+0x166/0x240 fs/buffer.c:2203 ext4_da_write_end+0x59b/0x760 fs/ext4/inode.c:3112 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3586 ext4_buffered_write_iter+0x2e5/0x3e0 fs/ext4/file.c:269 ext4_file_write_iter+0x48a/0x10b0 fs/ext4/file.c:502 call_write_iter include/linux/fs.h:1977 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x7a6/0xe20 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 24883 Comm: syz-executor.4 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================