================================================================== BUG: KCSAN: data-race in do_mpage_readpage / set_blocksize write to 0xffff88810135a4be of 1 bytes by task 19214 on cpu 0: set_blocksize+0x20a/0x270 fs/block_dev.c:165 sb_set_blocksize+0x2c/0xa0 fs/block_dev.c:175 ext4_fill_super+0x20de/0x8010 fs/ext4/super.c:4466 mount_bdev+0x1e8/0x290 fs/super.c:1368 ext4_mount+0x2d/0x40 fs/ext4/super.c:6632 legacy_get_tree+0x70/0xc0 fs/fs_context.c:592 vfs_get_tree+0x4a/0x1a0 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x11d4/0x1ce0 fs/namespace.c:3235 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 0xffff88810135a4be of 1 bytes by task 19219 on cpu 1: do_mpage_readpage+0x6c/0x10b0 fs/mpage.c:160 mpage_readahead+0x149/0x280 fs/mpage.c:389 blkdev_readahead+0x18/0x20 fs/block_dev.c:649 read_pages+0x9f/0x530 mm/readahead.c:130 page_cache_ra_unbounded+0x3c8/0x410 mm/readahead.c:238 do_page_cache_ra mm/readahead.c:267 [inline] force_page_cache_ra+0x246/0x280 mm/readahead.c:299 page_cache_sync_ra+0xcc/0xe0 mm/readahead.c:573 page_cache_sync_readahead include/linux/pagemap.h:879 [inline] filemap_get_pages mm/filemap.c:2467 [inline] filemap_read+0x388/0x1230 mm/filemap.c:2550 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701 blkdev_read_iter+0xb9/0xf0 fs/block_dev.c:1732 call_read_iter include/linux/fs.h:2108 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x565/0x5d0 fs/read_write.c:496 ksys_read+0xce/0x180 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:642 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: 1 PID: 19219 Comm: systemd-udevd Not tainted 5.13.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================