VOMIT (go/vomit) has received an external vulnerability report for the Linux kernel.
Advisory: CVE-2018-12896
Details: http://vomit.googleplex.com/advisory?id=CVE/CVE-2018-12896
CVSS severity score: 2.1/10.0
Description:
An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls.
This bug was filed by http://go/vomit
Please contact us at vomit-team@google.com if you need any assistance.
Comment 1 by zsm@google.com
, Sep 5Labels: Security_Severity-Low Security_Impact-Stable Pri-3
Owner: zsm@chromium.org
Status: WontFix (was: Untriaged)
Upstream commit is 78c9c4df ("posix-timers: Sanitize overrun handling"). Our kernels do not seem to have this commit. Commit applies cleanly to v4.14. The patch does not apply cleanly to v4.4. As this seems to be a low severity bug, I'll mark this as WontFix.