From: Laura Abbott <lauraa@codeaurora.org>
To: linux-mm@kvack.org, benh@kernel.crashing.org, yinghai@kernel.org
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
Laura Abbott <lauraa@codeaurora.org>
Subject: [PATCH] mm/memblock.c: Correctly check whether to trim a block
Date: Wed, 28 Mar 2012 19:25:58 -0700 [thread overview]
Message-ID: <1332987958-10766-1-git-send-email-lauraa@codeaurora.org> (raw)
Currently in __memblock_remove, the check to trim the top of
a block off only checks if the requested base is less than the
memblock end. If the end of the requested region is equal to
the start of a memblock, this will incorrectly try to remove
the block, possibly causing an integer underflow:
---------------------------------------
| | |
| | |
base end = rgn->base rend
An additional check is needed to see if the end of the requested
region is greater than the memblock region:
----------------------
| |
| |
rgn->base base rend end
| |
| |
--------------------
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
---
mm/memblock.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/mm/memblock.c b/mm/memblock.c
index 5338237..e174ee0 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -459,7 +459,7 @@ static long __init_memblock __memblock_remove(struct memblock_type *type,
}
/* And check if we need to trim the top of a block */
- if (base < rend)
+ if (base < rend && end > rend)
rgn->size -= rend - base;
}
--
1.7.8.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next reply other threads:[~2012-03-29 2:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-29 2:25 Laura Abbott [this message]
2012-03-29 4:01 ` [PATCH] mm/memblock.c: Correctly check whether to trim a block Benjamin Herrenschmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1332987958-10766-1-git-send-email-lauraa@codeaurora.org \
--to=lauraa@codeaurora.org \
--cc=benh@kernel.crashing.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=yinghai@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).