From: "René Scharfe" <l.s.r@web.de>
To: Git List <git@vger.kernel.org>
Cc: Jeff King <peff@peff.net>
Subject: [PATCH v2 1/2] apply: avoid fixed-size buffer in create_one_file()
Date: Fri, 5 Apr 2024 12:53:23 +0200 [thread overview]
Message-ID: <1b5f3b1d-60e2-4fe7-9ac8-a63ad861cd16@web.de> (raw)
In-Reply-To: <df774306-f29b-4a75-a282-59db89812b9a@web.de>
PATH_MAX is not always a hard limit and 'path' in create_one_file()
could be longer -- it's taken from the patch file and allocated
dynamically. Allocate the name of the temporary file on the heap as
well instead of using a fixed-size buffer to avoid that arbitrary limit.
Resist the temptation of using the more convenient mkpath() to avoid
introducing a dependency on a static variable deep inside the apply
machinery.
Take care to work around (arguably buggy) implementations of free(3)
that modify errno, by calling it only after using the errno value.
Suggested-by: Jeff King <peff@peff.net>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: René Scharfe <l.s.r@web.de>
---
Changes since v1:
- Split out removal of mksnpath() into a separate patch.
- Use errno only before calling free(3).
apply.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/apply.c b/apply.c
index 432837a674..e171b42904 100644
--- a/apply.c
+++ b/apply.c
@@ -4441,6 +4441,7 @@ static int create_one_file(struct apply_state *state,
const char *buf,
unsigned long size)
{
+ char *newpath = NULL;
int res;
if (state->cached)
@@ -4502,24 +4503,26 @@ static int create_one_file(struct apply_state *state,
unsigned int nr = getpid();
for (;;) {
- char newpath[PATH_MAX];
- mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
+ newpath = mkpathdup("%s~%u", path, nr);
res = try_create_file(state, newpath, mode, buf, size);
if (res < 0)
- return -1;
+ goto out;
if (!res) {
if (!rename(newpath, path))
- return 0;
+ goto out;
unlink_or_warn(newpath);
break;
}
if (errno != EEXIST)
break;
++nr;
+ FREE_AND_NULL(newpath);
}
}
- return error_errno(_("unable to write file '%s' mode %o"),
- path, mode);
+ res = error_errno(_("unable to write file '%s' mode %o"), path, mode);
+out:
+ free(newpath);
+ return res;
}
static int add_conflicted_stages_file(struct apply_state *state,
--
2.44.0
next prev parent reply other threads:[~2024-04-05 10:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-04 21:08 [PATCH] apply: replace mksnpath() with a mkpathdup() call René Scharfe
2024-04-04 21:29 ` Junio C Hamano
2024-04-04 22:53 ` free and errno, was " Jeff King
2024-04-04 23:08 ` Junio C Hamano
2024-04-05 10:52 ` René Scharfe
2024-04-05 17:35 ` Jeff King
2024-04-05 17:41 ` Jeff King
2024-04-06 17:45 ` René Scharfe
2024-04-07 1:18 ` Jeff King
2024-04-14 15:17 ` René Scharfe
2024-04-24 1:11 ` Jeff King
2024-04-05 10:53 ` René Scharfe [this message]
2024-04-05 10:56 ` [PATCH v2 2/2] path: remove mksnpath() René Scharfe
2024-04-05 17:37 ` Jeff King
2024-04-05 16:51 ` [PATCH v2 1/2] apply: avoid fixed-size buffer in create_one_file() Junio C Hamano
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=1b5f3b1d-60e2-4fe7-9ac8-a63ad861cd16@web.de \
--to=l.s.r@web.de \
--cc=git@vger.kernel.org \
--cc=peff@peff.net \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).