Cal. Com. Code § 9604
(a) If an obligation secured by a security interest in personal property or fixtures is also secured by an interest in real property or an estate therein:
(1) The secured party may do any of the following:
(2)
(3)
(4) If the secured party realizes proceeds from the disposition of collateral that is personal property or fixtures, the following provisions shall apply:
(7) If a secured party fails to comply with the procedures applicable to real property in proceeding as to both real and personal property under subparagraph (B) of paragraph (1), a purchaser for value of any interest in the real property at judicial or nonjudicial foreclosure proceedings conducted pursuant to subparagraph (B) of paragraph (1) takes that interest free from any claim or interest of another person, or any defect in title, based upon that noncompliance, unless:
(B) The purchaser is other than the secured party and at the time of sale of the real property at that foreclosure the purchaser had knowledge of the failure to comply with this chapter and that the noncompliance occurred other than in good faith.
Even if the purchaser at the foreclosure sale does not take his or her interest free of claims, interests, or title defects based upon that noncompliance with this chapter, a subsequent purchaser for value who acquires an interest in that real property from the purchaser at that foreclosure takes that interest free from any claim or interest of another person, or any defect in title, based upon that noncompliance, unless at the time of acquiring the interest the subsequent purchaser has knowledge of the failure to comply with this chapter and that the noncompliance occurred other than in good faith.