Re: Segmentation fault in git apply
From: Junio C Hamano <hidden>
Date: 2016-06-15 23:03:36
Subsystem:
the rest · Maintainer:
Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-06-15 · Re: Segmentation fault in git apply · Kyle J. McKay <hidden>
- 2016-06-15 · Re: Segmentation fault in git apply · Kyle J. McKay <hidden>
- 2016-06-15 · Re: Segmentation fault in git apply · Michael Blume <hidden>
- 2016-06-15 · Re: Segmentation fault in git apply · Michael Blume <hidden>
- 2016-06-15 · Segmentation fault in git apply · Michael Blume <hidden>
"Kyle J. McKay" [off-list ref] writes:
quoted hunk
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