[LU-4787] OOPS from null pointer dereference in mdc_unpack_acl

• Type: Bug
• Resolution: Duplicate
• Priority: Major
• Fix Version/s: Lustre 2.6.0
• Affects Version/s: Lustre 2.6.0, Lustre 2.5.1, Lustre 2.4.3
• Environment: ZFS based 2.5.1 MGS/MDS/OSS + 2.5.1 or in-kernel client
• Severity: 3
• Assignee: WC Triage
• Reporter: Roland Fehrenbacher

Description

A kernel oops is generated when body->aclsize != 0 in mdc_unpack_acl, but posix_acl_from_xattr
returns a null pointer. The pointer is checked for error codes, but not for a null value.
The cause of the problem is most likely some data corruption on the MDT side, but the client should tolerate this by sending an error.

Issue Links

• is related to: LU-5150 NULL pointer dereference in posix_acl_valid() under mdc_get_lustre_md()