linux-kernel - [PATCH 0/2] Address issues in dma-debug API

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20130318220241.7349.5030.stgit@ahduyck-cp1.jf.intel.com>
Date:	Mon, 18 Mar 2013 15:12:38 -0700
From:	Alexander Duyck <alexander.h.duyck@...el.com>
To:	linux-kernel@...r.kernel.org
Cc:	konrad.wilk@...cle.com, joerg.roedel@....com, konrad@...nel.org,
	christoph.paasch@...ouvain.be, mingo@...hat.com,
	shuahkhan@...il.com, hpa@...or.com, akpm@...ux-foundation.org,
	shuah.khan@...com, netdev@...r.kernel.org,
	jeffrey.t.kirsher@...el.com
Subject: [PATCH 0/2] Address issues in dma-debug API

Christoph Paasch recently reported a "device driver failed to check map 
error" on igb.  However after reviewing the code there was no possibility of
that.  On closer inspection there was a bug in the DMA debug API that was
causing the issue.  These two patches address the issues I found.

The first issue I found while trying to implement a workaround.  Specifically
the problem is a locking bug which is triggered if a multiple mapped buffer
exists and there is not an exact match for the unmap.  This results in the CPU
becoming deadlocked.

The second issue, which was the original problem, is resolved by guaranteeing
that if we call dma_mapping_error we set a matching entry to MAP_ERR_CHECKED
that was not previously set. 

I'm not sure if these are critical enough to go into one of the upcoming RC
kernels or if these can wait until the merge since this is in a debugging API.
I'm leaving that for the sub-maintainers to decide.

---

Alexander Duyck (2):
      dma-debug: Fix locking bug in check_unmap
      dma-debug: Update DMA debug API to better handle multiple mappings of a buffer

 lib/dma-debug.c |   42 ++++++++++++++++++++++++++++--------------
 1 files changed, 28 insertions(+), 14 deletions(-)

-- 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/