EXT4-fs (loop0): couldn't mount as ext2 due to feature incompatibilities ================================================================== BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru read-write to 0xffff888237d266e8 of 1 bytes by task 9730 on cpu 1: folio_batch_add include/linux/folio_batch.h:77 [inline] __folio_batch_add_and_move mm/swap.c:194 [inline] folio_add_lru+0xaa/0x1f0 mm/swap.c:517 folio_add_lru_vma+0x49/0x70 mm/swap.c:536 wp_page_copy mm/memory.c:3943 [inline] do_wp_page+0x13b1/0x2040 mm/memory.c:4336 handle_pte_fault mm/memory.c:6443 [inline] __handle_mm_fault mm/memory.c:6565 [inline] handle_mm_fault+0x8bb/0x2e70 mm/memory.c:6734 do_user_addr_fault+0x3fd/0x1050 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 __put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:97 ____sys_recvmsg+0x1a1/0x280 net/socket.c:2931 ___sys_recvmsg+0x11f/0x3b0 net/socket.c:2960 do_recvmmsg+0x1ef/0x560 net/socket.c:3055 __sys_recvmmsg net/socket.c:3129 [inline] __do_sys_recvmmsg net/socket.c:3152 [inline] __se_sys_recvmmsg net/socket.c:3145 [inline] __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3145 x64_sys_call+0x80f/0x3020 arch/x86/include/generated/asm/syscalls_64.h:300 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888237d266e8 of 1 bytes by task 9741 on cpu 0: folio_batch_count include/linux/folio_batch.h:56 [inline] cpu_needs_drain mm/swap.c:786 [inline] __lru_add_drain_all+0x17e/0x450 mm/swap.c:883 lru_add_drain_all+0x10/0x20 mm/swap.c:899 invalidate_bdev+0x47/0x70 block/bdev.c:101 __ext4_fill_super fs/ext4/super.c:5799 [inline] ext4_fill_super+0x2cf6/0x37c0 fs/ext4/super.c:5824 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694 get_tree_bdev+0x1f/0x30 fs/super.c:1717 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5856 vfs_get_tree+0x57/0x1d0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x288/0x8d0 fs/namespace.c:3834 path_mount+0x4d0/0xbc0 fs/namespace.c:4154 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x19 -> 0x1a Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 9741 Comm: syz.0.1353 Tainted: G W syzkaller #0 PREEMPT(lazy) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 ================================================================== loop0: detected capacity change from 0 to 256 FAT-fs (loop0): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive! netlink: 44 bytes leftover after parsing attributes in process `syz.0.1353'.