CVE-2019-11599

Published: 29 April 2019

The coredump implementation in the Linux kernel before 5.0.10 does not use locking or other mechanisms to prevent vma layout or vma flags changes while it runs, which allows local users to obtain sensitive information, cause a denial of service, or possibly have unspecified other impact by triggering a race condition with mmget_not_zero or get_task_mm calls. This is related to fs/userfaultfd.c, mm/mmap.c, fs/proc/task_mmu.c, and drivers/infiniband/core/uverbs_main.c.

From the Ubuntu Security Team

Jann Horn discovered that a race condition existed in the Linux kernel when performing core dumps. A local attacker could use this to cause a denial of service (system crash) or expose sensitive information.

Notes

While the upstream commit has a Fixes tag that suggests the flaw was
introduced in v4.3, the commit message makes it clear that the issue exists
since before the kernel was stored in git.

Status

Severity score breakdown

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-11599
• http://www.openwall.com/lists/oss-security/2019/04/29/1
• http://www.openwall.com/lists/oss-security/2019/04/29/2
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=04f5866e41fb70690e28397487d8bd8eea7d712a
• https://ubuntu.com/security/notices/USN-4069-1
• https://ubuntu.com/security/notices/USN-4069-2
• https://ubuntu.com/security/notices/USN-4095-1
• https://ubuntu.com/security/notices/USN-4115-1
• https://ubuntu.com/security/notices/USN-4118-1
• NVD
• Launchpad
• Debian

Bugs

• https://bugs.chromium.org/p/project-zero/issues/detail?id=1790