From: "Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
To: git@vger.kernel.org, "René Scharfe" <rene.scharfe@lsrfire.ath.cx>,
"Thomas Rast" <trast@student.ethz.ch>,
"Junio C Hamano" <gitster@pobox.com>
Cc: "Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
Subject: [PATCH] parse_tag_buffer(): avoid out of bound access
Date: Fri, 18 Feb 2011 19:49:32 +0700 [thread overview]
Message-ID: <1298033372-29069-1-git-send-email-pclouds@gmail.com> (raw)
In-Reply-To: <4D5D17F7.4010003@lsrfire.ath.cx>
There is a check (size < 64) at the beginning of the function, but
that only covers object+type lines. Code for parsing "tag" and
"tagger" may access outside buffer. Fix it.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
On Thu, Feb 17, 2011 at 7:43 PM, René Scharfe <rene.scharfe@lsrfire.ath.cx> wrote:
> memchr() won't notice if a negative value has been passed as third parameter
> because its type is size_t, which is unsigned. Negative values are
> converted to big positive ones..
I did not notice that. Fixed commit message.
tag.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/tag.c b/tag.c
index ecf7c1e..7d38cc0 100644
--- a/tag.c
+++ b/tag.c
@@ -97,7 +97,9 @@ int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
item->tagged = NULL;
}
- if (prefixcmp(bufptr, "tag "))
+ if (bufptr + 4 < tail && !prefixcmp(bufptr, "tag "))
+ ; /* good */
+ else
return -1;
bufptr += 4;
nl = memchr(bufptr, '\n', tail - bufptr);
@@ -106,7 +108,7 @@ int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
item->tag = xmemdupz(bufptr, nl - bufptr);
bufptr = nl + 1;
- if (!prefixcmp(bufptr, "tagger "))
+ if (bufptr + 7 < tail && !prefixcmp(bufptr, "tagger "))
item->date = parse_tag_date(bufptr, tail);
else
item->date = 0;
--
1.7.4.74.g639db
prev parent reply other threads:[~2011-02-18 12:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-05 10:52 [PATCH 1/2] Add const to parse_{commit,tag}_buffer() Nguyễn Thái Ngọc Duy
2011-02-05 10:52 ` [PATCH 2/2] Make hash-object more robust against malformed objects Nguyễn Thái Ngọc Duy
2011-02-12 11:42 ` Thomas Rast
2011-02-12 14:47 ` Nguyen Thai Ngoc Duy
2011-02-14 13:02 ` [PATCH] parse_tag_buffer(): do not prefixcmp() out of range Nguyễn Thái Ngọc Duy
2011-02-15 21:18 ` Junio C Hamano
2011-02-16 3:39 ` Nguyen Thai Ngoc Duy
2011-02-17 12:43 ` René Scharfe
2011-02-18 12:49 ` Nguyễn Thái Ngọc Duy [this message]
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