CVE-2022-0847

A flaw was found in the way the flags member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe and push_pipe functions in the Linux kernel and could thus contain stale values. An unprivileged local user could use this flaw to write to pages in the page cache backed by read only files and as such escalate their privileges on the system.

Weakness

The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable’s type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• http://packetstormsecurity.com/files/166229/Dirty-Pipe-Linux-Privilege-Escalation.html
• http://packetstormsecurity.com/files/166230/Dirty-Pipe-SUID-Binary-Hijack-Privilege-Escalation.html
• http://packetstormsecurity.com/files/166258/Dirty-Pipe-Local-Privilege-Escalation.html
• http://packetstormsecurity.com/files/176534/Linux-4.20-KTLS-Read-Only-Write.html
• https://bugzilla.redhat.com/show_bug.cgi?id=2060795
• https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
• https://dirtypipe.cm4all.com/
• https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2022-0015
• https://security.netapp.com/advisory/ntap-20220325-0005/
• https://www.suse.com/support/kb/doc/?id=000020603