================================================================== BUG: KCSAN: data-race in __delayacct_blkio_end / __delayacct_blkio_start write to 0xffff888100be0b48 of 8 bytes by task 8545 on cpu 0: __delayacct_blkio_start+0x35/0x40 kernel/delayacct.c:61 delayacct_blkio_start include/linux/delayacct.h:119 [inline] __schedule+0x18c/0x550 kernel/sched/core.c:4485 schedule+0x7f/0xb0 kernel/sched/core.c:4601 io_schedule+0x3b/0x50 kernel/sched/core.c:6295 wait_on_page_bit_common+0x633/0x910 mm/filemap.c:1273 wait_on_page_bit_killable mm/filemap.c:1341 [inline] wait_on_page_locked_killable include/linux/pagemap.h:681 [inline] generic_file_buffered_read+0x5ff/0x2110 mm/filemap.c:2261 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2535 ext4_file_read_iter+0x2d0/0x420 fs/ext4/file.c:74 call_read_iter include/linux/fs.h:1881 [inline] generic_file_splice_read+0x22a/0x310 fs/splice.c:311 do_splice_to fs/splice.c:788 [inline] splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x574/0xb70 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff888100be0b48 of 8 bytes by task 8555 on cpu 1: delayacct_end kernel/delayacct.c:48 [inline] __delayacct_blkio_end+0x70/0xf0 kernel/delayacct.c:82 delayacct_blkio_end include/linux/delayacct.h:125 [inline] try_to_wake_up+0x107/0x470 kernel/sched/core.c:2892 wake_page_function+0xd9/0x200 mm/filemap.c:1080 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:93 wake_up_page_bit+0xa4/0x190 mm/filemap.c:1113 unlock_page+0x5e/0x70 mm/filemap.c:1465 ext4_mpage_readpages+0xffe/0x1360 arch/x86/include/asm/bitops.h:55 ext4_readpage+0xbc/0x180 fs/ext4/inode.c:3239 generic_file_buffered_read+0xa30/0x2110 mm/filemap.c:2384 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2535 ext4_file_read_iter+0x2d0/0x420 fs/ext4/file.c:74 call_read_iter include/linux/fs.h:1881 [inline] generic_file_splice_read+0x22a/0x310 fs/splice.c:311 do_splice_to fs/splice.c:788 [inline] splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x574/0xb70 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 8555 Comm: syz-executor.0 Not tainted 5.10.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================