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Commit 4e240d1b authored by Jaegeuk Kim's avatar Jaegeuk Kim
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f2fs: check memory boundary by insane namelen 



If namelen is corrupted to have very long value, fill_dentries can copy
wrong memory area.

Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 1e771e83

fs/f2fs/dir.c

+11 −1
Original line number Diff line number Diff line
@@ -808,6 +808,17 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, 
		de_name.name = d->filename[bit_pos];

		de_name.len = le16_to_cpu(de->name_len);



		/* check memory boundary before moving forward */

		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));

		if (unlikely(bit_pos > d->max)) {

			f2fs_msg(sbi->sb, KERN_WARNING,

				"%s: corrupted namelen=%d, run fsck to fix.",

				__func__, le16_to_cpu(de->name_len));

			set_sbi_flag(sbi, SBI_NEED_FSCK);

			err = -EINVAL;

			goto out;

		}



		if (f2fs_encrypted_inode(d->inode)) {

			int save_len = fstr->len;
@@ -830,7 +841,6 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, 
		if (readdir_ra)

			f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));



		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));

		ctx->pos = start_pos + bit_pos;

	}

out: