Hello, syzbot found the following issue on: HEAD commit: ec2df4364666 Merge tag 'spi-fix-v6.16-rc7' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1567c782580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c0dd0a92e88efc24 dashboard link: https://syzkaller.appspot.com/bug?extid=d3c29ed63db6ddf8406e compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/29b468ddeacc/disk-ec2df436.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/996435d5d9de/vmlinux-ec2df436.xz kernel image: https://storage.googleapis.com/syzbot-assets/170fc9879e1c/bzImage-ec2df436.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d3c29ed63db6ddf8406e@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KCSAN: data-race in fat32_ent_get / fat32_ent_put read-write to 0xffff88810b7b319c of 4 bytes by task 7231 on cpu 0: fat32_ent_put+0x4e/0x90 fs/fat/fatent.c:191 fat_ent_write+0x6c/0xe0 fs/fat/fatent.c:417 fat_chain_add+0x15b/0x3f0 fs/fat/misc.c:136 fat_add_cluster fs/fat/inode.c:112 [inline] __fat_get_block fs/fat/inode.c:154 [inline] fat_get_block+0x46c/0x5e0 fs/fat/inode.c:189 __block_write_begin_int+0x400/0xf90 fs/buffer.c:2151 block_write_begin fs/buffer.c:2262 [inline] cont_write_begin+0x5fc/0x970 fs/buffer.c:2601 fat_write_begin+0x4f/0xe0 fs/fat/inode.c:228 generic_perform_write+0x184/0x490 mm/filemap.c:4112 __generic_file_write_iter+0xec/0x120 mm/filemap.c:4226 generic_file_write_iter+0x8d/0x2f0 mm/filemap.c:4255 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x4a0/0x8e0 fs/read_write.c:686 ksys_write+0xda/0x1a0 fs/read_write.c:738 __do_sys_write fs/read_write.c:749 [inline] __se_sys_write fs/read_write.c:746 [inline] __x64_sys_write+0x40/0x50 fs/read_write.c:746 x64_sys_call+0x2cdd/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88810b7b319c of 4 bytes by task 7250 on cpu 1: fat32_ent_get+0x24/0x80 fs/fat/fatent.c:149 fat_count_free_clusters+0x50e/0x760 fs/fat/fatent.c:741 fat_statfs+0xc0/0x200 fs/fat/inode.c:834 statfs_by_dentry fs/statfs.c:66 [inline] vfs_statfs+0xc8/0x1c0 fs/statfs.c:90 user_statfs+0x71/0x110 fs/statfs.c:105 __do_sys_statfs fs/statfs.c:193 [inline] __se_sys_statfs fs/statfs.c:190 [inline] __x64_sys_statfs+0x65/0xf0 fs/statfs.c:190 x64_sys_call+0x1edd/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:138 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0fffffff -> 0x00000068 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 7250 Comm: syz.4.1276 Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
