================================================================== BUG: KCSAN: data-race in ext4_mb_good_group / mb_free_blocks write to 0xffff8881010d6614 of 4 bytes by task 12986 on cpu 1: mb_free_blocks+0x156/0xb40 fs/ext4/mballoc.c:1802 ext4_mb_release_inode_pa+0x301/0x570 fs/ext4/mballoc.c:4766 ext4_discard_preallocations+0x7c6/0xb60 fs/ext4/mballoc.c:5030 ext4_truncate+0x71e/0xa80 fs/ext4/inode.c:4265 ext4_setattr+0xb00/0xef0 fs/ext4/inode.c:5521 notify_change+0x8a3/0xac0 fs/attr.c:410 do_truncate+0xf7/0x140 fs/open.c:64 handle_truncate fs/namei.c:3082 [inline] do_open fs/namei.c:3430 [inline] path_openat+0x1925/0x1ec0 fs/namei.c:3559 do_filp_open+0x105/0x220 fs/namei.c:3586 do_sys_openat2+0xb5/0x2b0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_openat fs/open.c:1232 [inline] __se_sys_openat fs/open.c:1227 [inline] __x64_sys_openat+0xef/0x110 fs/open.c:1227 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881010d6614 of 4 bytes by task 12989 on cpu 0: ext4_mb_good_group+0x131/0x370 fs/ext4/mballoc.c:2432 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2545 [inline] ext4_mb_regular_allocator+0x1610/0x2530 fs/ext4/mballoc.c:2747 ext4_mb_new_blocks+0x792/0x1fc0 fs/ext4/mballoc.c:5586 ext4_alloc_branch fs/ext4/indirect.c:333 [inline] ext4_ind_map_blocks+0xb1b/0x16d0 fs/ext4/indirect.c:628 ext4_map_blocks+0x6e3/0xf00 fs/ext4/inode.c:639 ext4_iomap_alloc fs/ext4/inode.c:3432 [inline] ext4_iomap_begin+0x4b0/0x630 fs/ext4/inode.c:3482 iomap_iter+0x39c/0x470 fs/iomap/iter.c:74 __iomap_dio_rw+0xbe3/0x1010 fs/iomap/direct-io.c:568 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649 ext4_dio_write_iter fs/ext4/file.c:568 [inline] ext4_file_write_iter+0xa72/0x11f0 fs/ext4/file.c:678 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x79c/0x8d0 fs/read_write.c:594 ksys_write+0xd9/0x190 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:656 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00007fbe -> 0x00007fd7 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 12989 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================