From: Junio C Hamano <gitster@pobox•com>
To: "Kyle J. McKay" <mackyle@gmail•com>
Cc: Michael Blume <blume.mike@gmail•com>, Git List <git@vger•kernel.org>
Subject: Re: Segmentation fault in git apply
Date: Fri, 16 Jan 2015 11:58:55 -0800 [thread overview]
Message-ID: <xmqqbnly1oqo.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <4157F6B0-DDF4-4F71-A09B-EE216537CA89@gmail.com> (Kyle J. McKay's message of "Thu, 15 Jan 2015 01:10:20 -0800")
"Kyle J. McKay" <mackyle@gmail•com> writes:
> If I make this change on top of 250b3c6c:
>
> diff --git a/builtin/apply.c b/builtin/apply.c
> index df773c75..8795e830 100644
> --- a/builtin/apply.c
> +++ b/builtin/apply.c
> @@ -2390,6 +2390,8 @@ static int match_fragment(struct image *img,
> fixed_buf = strbuf_detach(&fixed, &fixed_len);
> if (postlen < postimage->len)
> postlen = 0;
> + if (postlen)
> + postlen = 2 * postimage->len;
> update_pre_post_images(preimage, postimage,
> fixed_buf, fixed_len, postlen);
> return 1;
>
> Then the problem goes away. That seems to suggest that postlen is
> being computed incorrectly, but someone more familiar with
> bulitin/apply.c is going to need to look at it.
Indeed, with this, the test case detects under-counting in the
caller (the caller counts 262 bytes but the expansion consumes 273
bytes).
-- >8 --
Subject: apply: make update_pre_post_images() sanity check the given postlen
---
builtin/apply.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/builtin/apply.c b/builtin/apply.c
index 622ee16..18b7997 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -2174,6 +2174,10 @@ static void update_pre_post_images(struct image *preimage,
/* Fix the length of the whole thing */
postimage->len = new - postimage->buf;
postimage->nr -= reduced;
+
+ if (postlen && postlen < (new - postimage->buf))
+ die("BUG: postlen = %d, used = %d",
+ (int)postlen, (int)(new - postimage->buf));
}
static int match_fragment(struct image *img,
--
2.3.0-rc0-149-g0286818
next prev parent reply other threads:[~2015-01-16 19:59 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-14 18:20 Segmentation fault in git apply Michael Blume
2015-01-14 18:40 ` Michael Blume
2015-01-14 18:44 ` Michael Blume
2015-01-14 18:48 ` Michael Blume
2015-01-14 18:58 ` Michael Blume
2015-01-14 19:09 ` Michael Blume
2015-01-15 8:26 ` Kyle J. McKay
2015-01-15 9:10 ` Kyle J. McKay
2015-01-16 19:58 ` Junio C Hamano [this message]
2015-01-16 23:54 ` [PATCH] apply: count the size of postimage correctly Junio C Hamano
2015-01-18 10:49 ` [PATCH] test: add git apply whitespace expansion tests Kyle J. McKay
2015-01-18 22:11 ` Junio C Hamano
2015-01-19 3:54 ` Kyle J. McKay
2015-01-21 22:33 ` Junio C Hamano
2015-01-22 6:55 ` Kyle J. McKay
2015-01-22 19:23 ` Junio C Hamano
2015-01-23 0:12 ` Kyle J. McKay
2015-01-22 22:58 ` [PATCH v2 0/4] apply --whitespace=fix buffer corruption fix Junio C Hamano
2015-01-22 22:58 ` [PATCH v2 1/4] apply.c: typofix Junio C Hamano
2015-01-22 23:17 ` Stefan Beller
2015-01-22 23:42 ` Junio C Hamano
2015-01-22 23:48 ` Stefan Beller
2015-01-22 22:58 ` [PATCH v2 2/4] apply: make update_pre_post_images() sanity check the given postlen Junio C Hamano
2015-01-22 22:58 ` [PATCH v2 3/4] apply: count the size of postimage correctly Junio C Hamano
2015-01-22 22:58 ` [PATCH v2 4/4] apply: detect and mark whitespace errors in context lines when fixing Junio C Hamano
2015-01-14 18:50 ` Segmentation fault in git apply Junio C Hamano
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