ntfs3(loop5): Failed to initialize $Extend.
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BUG: KMSAN: uninit-value in ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825
 ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825
 iomap_iter+0x9b7/0x1540 fs/iomap/iter.c:110
 __iomap_dio_rw+0x2891/0x3a10 fs/iomap/direct-io.c:795
 iomap_dio_rw+0x5d/0x180 fs/iomap/direct-io.c:890
 ntfs_file_read_iter+0x1081/0x13b0 fs/ntfs3/file.c:886
 copy_splice_read+0xa01/0x1170 fs/splice.c:362
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x787/0x1560 fs/splice.c:1084
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x1e0/0x350 fs/splice.c:1228
 do_sendfile+0x9fc/0x1130 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64+0x1ea/0x290 fs/read_write.c:1419
 __x64_sys_sendfile64+0xbd/0x120 fs/read_write.c:1419
 x64_sys_call+0x3aa4/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable lcn created at:
 ntfs_iomap_begin+0x15d/0x1460 fs/ntfs3/inode.c:786
 iomap_iter+0x9b7/0x1540 fs/iomap/iter.c:110

CPU: 0 UID: 0 PID: 12286 Comm: syz.5.1393 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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