CVE-2020-10711

A NULL pointer dereference flaw was found in the Linux kernels SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocols category bitmap into the SELinux extensible bitmap via the ebitmap_netlbl_import routine. While processing the CIPSO restricted bitmap tag in the cipso_v4_parsetag_rbm routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel, resulting in a denial of service.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
• http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00008.html
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10711
• https://lists.debian.org/debian-lts-announce/2020/06/msg00012.html
• https://security.netapp.com/advisory/ntap-20200608-0001/
• https://usn.ubuntu.com/4411-1/
• https://usn.ubuntu.com/4412-1/
• https://usn.ubuntu.com/4413-1/
• https://usn.ubuntu.com/4414-1/
• https://usn.ubuntu.com/4419-1/
• https://www.debian.org/security/2020/dsa-4698
• https://www.debian.org/security/2020/dsa-4699
• https://www.openwall.com/lists/oss-security/2020/05/12/2