Bug 1597759 (CVE-2018-12896) - CVE-2018-12896 kernel: Integer overflow in kernel/time/posix-timers.c
Summary: CVE-2018-12896 kernel: Integer overflow in kernel/time/posix-timers.c
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2018-12896
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1597760 Engineering1597762 Red Hat1638044
Blocks: Embargoed1597761
TreeView+ depends on / blocked
 
Reported: 2018-07-03 14:53 UTC by Laura Pardo
Modified: 2021-02-17 00:01 UTC (History)
45 users (show)

Fixed In Version:
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Doc Text:
An issue was discovered in the Linux kernel where 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.
Clone Of:
Environment:
Last Closed: 2018-08-01 13:22:08 UTC

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Description Laura Pardo 2018-07-03 14:53:41 UTC 
An issue was discovered in the Linux kernel. 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.

References:

https://bugzilla.kernel.org/show_bug.cgi?id=200189 	

https://github.com/lcytxw/bug_repro/tree/master/bug_200189 	

https://marc.info/?t=153003602900042&r=1&w=2

https://marc.info/?t=153003602700045&r=1&w=2

A suggested upstream patch:

https://github.com/torvalds/linux/commit/78c9c4dfbf8c04883941445a195276bb4bb92c76
Comment 1 Laura Pardo 2018-07-03 14:55:10 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1597760]
Comment 6 Vladis Dronov 2018-08-01 13:22:08 UTC 
Note:

This bug is present in certain Red Hat products, but the security impact is absent. Therefore, we do not consider this bug to be a security flaw.
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