oss-sec mailing list archives
Re: CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c
From: Seth Arnold <seth.arnold () canonical com>
Date: Mon, 25 Nov 2013 17:20:17 -0800
On Tue, Nov 26, 2013 at 12:57:23AM +0000, Christey, Steven M. wrote:
Kurt said:The Genlock driver does not properly initialize all members of a structure before copying it to user space. This allows a local attacker to obtain potentially sensitive information from kernel stack memory via ioctl system calls.This should be classified as CWE-200 Information Disclosure, "memory leak" refers to memory being used and not released properly, resulting in out of memory conditions.In CWE, we discourage the "memory leak" term because it has multiple meanings and interpretations: (1) that memory is allocated but never released, or (2) that sensitive portions of memory are accidentally disclosed to untrusted parties. This request sounds like variant (2) of the varying uses of the "memory leak" term, although Kurt's interpretation seems to be that it's about variant (1), which further reinforces my personal desire to see that term go away forever.
I wrote a response to Kurt, suggesting that he had mis-diagnosed the problem but did not send my response when I found that his message said the same thing mine said once you replace his first ',' with a ';'. Try this instead:
This should be classified as CWE-200 Information Disclosure; "memory leak" refers to memory being used and not released properly, resulting in out of memory conditions.
[Kurt's words with the first comma replaced with a semicolon.] It's amazing what a difference two pixels can make. :)
Anyway... Note that, as this issue is described, "information disclosure" actually results from a root cause in which certain locations are not properly initialized. Thus CWE-665: Improper Initialization (or its child CWE-457 Use of Uninitialized Variable) are probably more appropriate characterizations of the core issue; in this case, it happens to lead to memory disclosure, but in other cases, it might lead to privilege escalation or other consequences (depending on how the uninitialized data is used.)
I came up with CWE 212 before I properly parsed Kurt's mail: CWE-212: Improper Cross-boundary Removal of Sensitive Data With so much to chose from it's surprising the fix is one line of code. :) Thanks
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Current thread:
- CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c Jonathan Salwan (Nov 25)
- Re: CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c Kurt Seifried (Nov 25)
- RE: CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c Christey, Steven M. (Nov 25)
- Re: CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c Seth Arnold (Nov 25)
- Re: CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c Ramon de C Valle (Nov 25)
- RE: CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c Christey, Steven M. (Nov 25)
- Re: CVE request: Kernel MSM - Memory leak in drivers/base/genlock.c Kurt Seifried (Nov 25)