Merge tag 'ntfs3_for_6.18' of https://github.com/Paragon-Software-Group/linux-ntfs3

Pull ntfs3 updates from Konstantin Komarov:
"Added:
- support for FS_IOC_{GET,SET}FSLABEL ioctl
- reject index allocation if $BITMAP is empty but blocks exist

Fixed:
- integer overflow in run_unpack()
- resource leak bug in wnd_extend()

Changed:
- pretend $Extend records as regular files
- stop using write_cache_pages"

* tag 'ntfs3_for_6.18' of https://github.com/Paragon-Software-Group/linux-ntfs3:
ntfs3: stop using write_cache_pages
fs/ntfs3: reject index allocation if $BITMAP is empty but blocks exist
fs/ntfs3: Fix a resource leak bug in wnd_extend()
fs: ntfs3: Fix integer overflow in run_unpack()
ntfs3: pretend $Extend records as regular files
ntfs3: add FS_IOC_SETFSLABEL ioctl
ntfs3: add FS_IOC_GETFSLABEL ioctl
ntfs3: transition magic number to shared constant

fs/ntfs3/bitmap.c

···
 		mark_buffer_dirty(bh);
 		unlock_buffer(bh);
 		/* err = sync_dirty_buffer(bh); */
+		put_bh(bh);
 
 		b0 = 0;
 		bits -= op;

fs/ntfs3/file.c

···
 	return 0;
 }
 
+static int ntfs_ioctl_get_volume_label(struct ntfs_sb_info *sbi, u8 __user *buf)
+{
+	if (copy_to_user(buf, sbi->volume.label, FSLABEL_MAX))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int ntfs_ioctl_set_volume_label(struct ntfs_sb_info *sbi, u8 __user *buf)
+{
+	u8 user[FSLABEL_MAX] = {0};
+	int len;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (copy_from_user(user, buf, FSLABEL_MAX))
+		return -EFAULT;
+
+	len = strnlen(user, FSLABEL_MAX);
+
+	return ntfs_set_label(sbi, user, len);
+}
+
 /*
  * ntfs_ioctl - file_operations::unlocked_ioctl
  */
···
 	switch (cmd) {
 	case FITRIM:
 		return ntfs_ioctl_fitrim(sbi, arg);
+	case FS_IOC_GETFSLABEL:
+		return ntfs_ioctl_get_volume_label(sbi, (u8 __user *)arg);
+	case FS_IOC_SETFSLABEL:
+		return ntfs_ioctl_set_volume_label(sbi, (u8 __user *)arg);
 	}
 	return -ENOTTY; /* Inappropriate ioctl for device. */
 }

fs/ntfs3/index.c

···
 			bmp_size = bmp_size_v = le32_to_cpu(bmp->res.data_size);
 		}
 
+		/*
+		 * Index blocks exist, but $BITMAP has zero valid bits.
+		 * This implies an on-disk corruption and must be rejected.
+		 */
+		if (in->name == I30_NAME &&
+		    unlikely(bmp_size_v == 0 && indx->alloc_run.count)) {
+			err = -EINVAL;
+			goto out1;
+		}
+
 		bit = bmp_size << 3;
 	}
 

fs/ntfs3/inode.c

···
 		   fname->home.seq == cpu_to_le16(MFT_REC_EXTEND)) {
 		/* Records in $Extend are not a files or general directories. */
 		inode->i_op = &ntfs_file_inode_operations;
+		mode = S_IFREG;
 	} else {
 		err = -EINVAL;
 		goto out;

fs/ntfs3/ntfs_fs.h

···
 		__le16 flags; // Cached current VOLUME_INFO::flags, VOLUME_FLAG_DIRTY.
 		u8 major_ver;
 		u8 minor_ver;
-		char label[256];
+		char label[FSLABEL_MAX];
 		bool real_dirty; // Real fs state.
 	} volume;
 

fs/ntfs3/run.c

···
 #include <linux/blkdev.h>
 #include <linux/fs.h>
 #include <linux/log2.h>
+#include <linux/overflow.h>
 
 #include "debug.h"
 #include "ntfs.h"
···
 
 			if (!dlcn)
 				return -EINVAL;
-			lcn = prev_lcn + dlcn;
+
+			if (check_add_overflow(prev_lcn, dlcn, &lcn))
+				return -EINVAL;
 			prev_lcn = lcn;
 		} else {
 			/* The size of 'dlcn' can't be > 8. */
 			return -EINVAL;
 		}
 
-		next_vcn = vcn64 + len;
+		if (check_add_overflow(vcn64, len, &next_vcn))
+			return -EINVAL;
+
 		/* Check boundary. */
 		if (next_vcn > evcn + 1)
 			return -EINVAL;
···
 			return -EINVAL;
 
 		run_buf += size_size + offset_size;
-		vcn64 += len;
+		if (check_add_overflow(vcn64, len, &vcn64))
+			return -EINVAL;
 
 #ifndef CONFIG_NTFS3_64BIT_CLUSTER
 		if (vcn64 > 0x100000000ull)