loop4: detected capacity change from 0 to 8192 FAT-fs (loop4): Volume was not properly unmounted. Some data may be corrupt. Please run fsck. ================================================================== BUG: KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode read-write to 0xffff8881065ceb28 of 4 bytes by task 165 on cpu 1: __writeback_single_inode+0x1f4/0x850 fs/fs-writeback.c:1716 writeback_sb_inodes+0x461/0xa30 fs/fs-writeback.c:1976 wb_writeback+0x262/0x640 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x1a8/0x940 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391 kthread+0x1d1/0x210 kernel/kthread.c:389 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 read to 0xffff8881065ceb28 of 4 bytes by task 12887 on cpu 0: __mark_inode_dirty+0x58/0x7e0 fs/fs-writeback.c:2497 mark_inode_dirty include/linux/fs.h:2485 [inline] generic_write_end+0x137/0x160 fs/buffer.c:2305 fat_write_end+0x4e/0x160 fs/fat/inode.c:242 cont_expand_zero fs/buffer.c:2509 [inline] cont_write_begin+0x350/0x860 fs/buffer.c:2567 fat_write_begin+0x51/0xe0 fs/fat/inode.c:228 generic_cont_expand_simple+0xaa/0x150 fs/buffer.c:2468 fat_cont_expand+0x3a/0x160 fs/fat/file.c:223 fat_setattr+0x2aa/0x840 fs/fat/file.c:513 notify_change+0x85c/0x8e0 fs/attr.c:552 do_truncate fs/open.c:65 [inline] do_ftruncate+0x3cf/0x460 fs/open.c:181 do_sys_ftruncate fs/open.c:196 [inline] __do_sys_ftruncate fs/open.c:201 [inline] __se_sys_ftruncate fs/open.c:199 [inline] __x64_sys_ftruncate+0x67/0xc0 fs/open.c:199 x64_sys_call+0x9d9/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:78 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0001003a -> 0x00010022 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 12887 Comm: syz.4.3349 Not tainted 6.13.0-rc2-syzkaller-00036-g231825b2e1ff #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 ================================================================== FAT-fs (loop4): error, clusters badly computed (1000 != 999) FAT-fs (loop4): Filesystem has been set read-only FAT-fs (loop4): error, clusters badly computed (1002 != 1000) FAT-fs (loop4): error, clusters badly computed (1004 != 1001) FAT-fs (loop4): error, clusters badly computed (1006 != 1002) FAT-fs (loop4): error, clusters badly computed (1008 != 1003) FAT-fs (loop4): error, clusters badly computed (1010 != 1004) FAT-fs (loop4): error, clusters badly computed (1011 != 1005) FAT-fs (loop4): error, clusters badly computed (1012 != 1006) FAT-fs (loop4): error, clusters badly computed (1013 != 1007) FAT-fs (loop4): error, clusters badly computed (1014 != 1008) FAT-fs (loop4): error, clusters badly computed (1015 != 1009) FAT-fs (loop4): error, clusters badly computed (1016 != 1010) FAT-fs (loop4): error, clusters badly computed (1017 != 1011) FAT-fs (loop4): error, clusters badly computed (1018 != 1012) FAT-fs (loop4): error, clusters badly computed (1019 != 1013) FAT-fs (loop4): error, clusters badly computed (1020 != 1014) FAT-fs (loop4): error, clusters badly computed (1021 != 1015) FAT-fs (loop4): error, clusters badly computed (1022 != 1016) FAT-fs (loop4): error, clusters badly computed (1023 != 1017) FAT-fs (loop4): error, clusters badly computed (1024 != 1018) FAT-fs (loop4): error, clusters badly computed (1025 != 1019) FAT-fs (loop4): error, clusters badly computed (1026 != 1020) FAT-fs (loop4): error, clusters badly computed (1027 != 1021) FAT-fs (loop4): error, clusters badly computed (1028 != 1022) FAT-fs (loop4): error, clusters badly computed (1029 != 1023) FAT-fs (loop4): error, clusters badly computed (1030 != 1024) FAT-fs (loop4): error, clusters badly computed (1031 != 1025) FAT-fs (loop4): error, clusters badly computed (1032 != 1026) FAT-fs (loop4): error, clusters badly computed (1033 != 1027) FAT-fs (loop4): error, clusters badly computed (1034 != 1028) FAT-fs (loop4): error, clusters badly computed (1035 != 1029) FAT-fs (loop4): error, clusters badly computed (1036 != 1030) FAT-fs (loop4): error, clusters badly computed (1037 != 1031) FAT-fs (loop4): error, clusters badly computed (1038 != 1032) FAT-fs (loop4): error, clusters badly computed (1039 != 1033) FAT-fs (loop4): error, clusters badly computed (1040 != 1034) FAT-fs (loop4): error, clusters badly computed (1041 != 1035) FAT-fs (loop4): error, clusters badly computed (1042 != 1036) FAT-fs (loop4): error, clusters badly computed (1043 != 1037) FAT-fs (loop4): error, clusters badly computed (1044 != 1038) FAT-fs (loop4): error, clusters badly computed (1045 != 1039) FAT-fs (loop4): error, clusters badly computed (1046 != 1040) FAT-fs (loop4): error, clusters badly computed (1047 != 1041) FAT-fs (loop4): error, clusters badly computed (1048 != 1042) FAT-fs (loop4): error, clusters badly computed (1049 != 1043) FAT-fs (loop4): error, clusters badly computed (1050 != 1044) FAT-fs (loop4): error, clusters badly computed (1051 != 1045) FAT-fs (loop4): error, clusters badly computed (1052 != 1046) FAT-fs (loop4): error, clusters badly computed (1053 != 1047)