Re: [PATCH v2] fs/ntfs3: Fix memory leak if fill_super failed

From: Kari Argillander
Date: Mon Oct 11 2021 - 17:50:58 EST

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On Tue, Oct 05, 2021 at 06:26:53PM +0300, Konstantin Komarov wrote:
> In ntfs_init_fs_context we allocate memory in fc->s_fs_info.
> In case of failed mount we must free it in ntfs_fill_super.
> We can't do it in ntfs_fs_free, because ntfs_fs_free called
> with fc->s_fs_info == NULL.
> fc->s_fs_info became NULL in sget_fc.

Thanks for fixing this. You can always ask that person who introduce bug
will fix it.

> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>

Reviewed-by: Kari Argillander <kari.argillander@xxxxxxxxx>

> ---
> v2:
> Changed fix - now we free memory instead of restoring pointer to memory.
> Added context how we allocate and free memory.
> Many commits affected, so no fixes tag.

Many commit affected, but fixed tag is the first one which introduce it.
This case:

Fixes: 610f8f5a7baf ("fs/ntfs3: Use new api for mounting")

This will help backporting fixes to stable branches.

>
> fs/ntfs3/super.c | 90 ++++++++++++++++++++++++++++++------------------
> 1 file changed, 56 insertions(+), 34 deletions(-)
>
> diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
> index 705d8b4f4894..d41d76979e12 100644
> --- a/fs/ntfs3/super.c
> +++ b/fs/ntfs3/super.c
> @@ -908,7 +908,8 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> if (IS_ERR(sbi->options->nls)) {
> sbi->options->nls = NULL;
> errorf(fc, "Cannot load nls %s", sbi->options->nls_name);
> - return -EINVAL;
> + err = -EINVAL;
> + goto out;
> }
>
> rq = bdev_get_queue(bdev);
> @@ -922,7 +923,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> err = ntfs_init_from_boot(sb, rq ? queue_logical_block_size(rq) : 512,
> bdev->bd_inode->i_size);
> if (err)
> - return err;
> + goto out;
>
> /*
> * Load $Volume. This should be done before $LogFile
> @@ -933,7 +934,8 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_VOLUME);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load $Volume.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> ni = ntfs_i(inode);
> @@ -954,19 +956,19 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> } else {
> /* Should we break mounting here? */
> //err = -EINVAL;
> - //goto out;
> + //goto put_inode_out;
> }
>
> attr = ni_find_attr(ni, attr, NULL, ATTR_VOL_INFO, NULL, 0, NULL, NULL);
> if (!attr || is_attr_ext(attr)) {
> err = -EINVAL;
> - goto out;
> + goto put_inode_out;
> }
>
> info = resident_data_ex(attr, SIZEOF_ATTRIBUTE_VOLUME_INFO);
> if (!info) {
> err = -EINVAL;
> - goto out;
> + goto put_inode_out;
> }
>
> sbi->volume.major_ver = info->major_ver;
> @@ -980,7 +982,8 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_MIRROR);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load $MFTMirr.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> sbi->mft.recs_mirr =
> @@ -994,14 +997,15 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_LOGFILE);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load \x24LogFile.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> ni = ntfs_i(inode);
>
> err = ntfs_loadlog_and_replay(ni, sbi);
> if (err)
> - goto out;
> + goto put_inode_out;
>
> iput(inode);
>
> @@ -1009,14 +1013,16 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> if (!sb_rdonly(sb)) {
> ntfs_warn(sb,
> "failed to replay log file. Can't mount rw!");
> - return -EINVAL;
> + err = -EINVAL;
> + goto out;
> }
> } else if (sbi->volume.flags & VOLUME_FLAG_DIRTY) {
> if (!sb_rdonly(sb) && !sbi->options->force) {
> ntfs_warn(
> sb,
> "volume is dirty and \"force\" flag is not set!");
> - return -EINVAL;
> + err = -EINVAL;
> + goto out;
> }
> }
>
> @@ -1027,7 +1033,8 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_MFT);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load $MFT.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> ni = ntfs_i(inode);
> @@ -1038,11 +1045,11 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
>
> err = wnd_init(&sbi->mft.bitmap, sb, tt);
> if (err)
> - goto out;
> + goto put_inode_out;
>
> err = ni_load_all_mi(ni);
> if (err)
> - goto out;
> + goto put_inode_out;
>
> sbi->mft.ni = ni;
>
> @@ -1052,7 +1059,8 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_BADCLUS);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load $BadClus.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> ni = ntfs_i(inode);
> @@ -1075,13 +1083,14 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_BITMAP);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load $Bitmap.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> #ifndef CONFIG_NTFS3_64BIT_CLUSTER
> if (inode->i_size >> 32) {
> err = -EINVAL;
> - goto out;
> + goto put_inode_out;
> }
> #endif
>
> @@ -1089,21 +1098,21 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> tt = sbi->used.bitmap.nbits;
> if (inode->i_size < bitmap_size(tt)) {
> err = -EINVAL;
> - goto out;
> + goto put_inode_out;
> }
>
> /* Not necessary. */
> sbi->used.bitmap.set_tail = true;
> err = wnd_init(&sbi->used.bitmap, sb, tt);
> if (err)
> - goto out;
> + goto put_inode_out;
>
> iput(inode);
>
> /* Compute the MFT zone. */
> err = ntfs_refresh_zone(sbi);
> if (err)
> - return err;
> + goto out;
>
> /* Load $AttrDef. */
> ref.low = cpu_to_le32(MFT_REC_ATTR);
> @@ -1111,18 +1120,19 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_ATTRDEF);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load $AttrDef -> %d", err);
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> if (inode->i_size < sizeof(struct ATTR_DEF_ENTRY)) {
> err = -EINVAL;
> - goto out;
> + goto put_inode_out;
> }
> bytes = inode->i_size;
> sbi->def_table = t = kmalloc(bytes, GFP_NOFS);
> if (!t) {
> err = -ENOMEM;
> - goto out;
> + goto put_inode_out;
> }
>
> for (done = idx = 0; done < bytes; done += PAGE_SIZE, idx++) {
> @@ -1131,7 +1141,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
>
> if (IS_ERR(page)) {
> err = PTR_ERR(page);
> - goto out;
> + goto put_inode_out;
> }
> memcpy(Add2Ptr(t, done), page_address(page),
> min(PAGE_SIZE, tail));
> @@ -1139,7 +1149,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
>
> if (!idx && ATTR_STD != t->type) {
> err = -EINVAL;
> - goto out;
> + goto put_inode_out;
> }
> }
>
> @@ -1173,12 +1183,13 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_UPCASE);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load $UpCase.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> if (inode->i_size != 0x10000 * sizeof(short)) {
> err = -EINVAL;
> - goto out;
> + goto put_inode_out;
> }
>
> for (idx = 0; idx < (0x10000 * sizeof(short) >> PAGE_SHIFT); idx++) {
> @@ -1188,7 +1199,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
>
> if (IS_ERR(page)) {
> err = PTR_ERR(page);
> - goto out;
> + goto put_inode_out;
> }
>
> src = page_address(page);
> @@ -1214,7 +1225,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> /* Load $Secure. */
> err = ntfs_security_init(sbi);
> if (err)
> - return err;
> + goto out;
>
> /* Load $Extend. */
> err = ntfs_extend_init(sbi);
> @@ -1239,19 +1250,30 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
> inode = ntfs_iget5(sb, &ref, &NAME_ROOT);
> if (IS_ERR(inode)) {
> ntfs_err(sb, "Failed to load root.");
> - return PTR_ERR(inode);
> + err = PTR_ERR(inode);
> + goto out;
> }
>
> sb->s_root = d_make_root(inode);
> - if (!sb->s_root)
> - return -ENOMEM;
> + if (!sb->s_root) {
> + err = -ENOMEM;
> + goto put_inode_out;
> + }
>
> fc->fs_private = NULL;
> - fc->s_fs_info = NULL;
>
> return 0;
> -out:
> +
> +put_inode_out:
> iput(inode);
> +out:
> + /*
> + * Free resources here.
> + * ntfs_fs_free will be called with fc->s_fs_info = NULL
> + */
> + put_ntfs(sbi);
> + sb->s_fs_info = NULL;
> +
> return err;
> }
>
> --
> 2.33.0
>

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