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Re: [PATCH 1/2] read-cache: fix memleak

From
Junio C Hamano <gitster@pobox.com>
Date
Mar 23, 2015, 18:11 UTC
Message-ID
<xmqqlhina8ip.fsf@gitster.dls.corp.google.com>
In-Reply-To
<1427133432-26703-1-git-send-email-sbeller@google.com>
Stefan Beller <sbeller@google.com> writes:
> `ce` is allocated in make_cache_entry and should be freed if it is not
> used any more. refresh_cache_entry as a wrapper around refresh_cache_ent
> will either return `ce` or a new updated cache entry which is allocated
> to new memory. In that case we need to free `ce` ourselfs.

Thanks. I started "commit --amend" to do s/ourselfs/ourselves/, but ended up tweaking the description a bit more.

-- .8 --
From: Stefan Beller <sbeller@google.com>
Date: Mon, 23 Mar 2015 10:57:11 -0700
Subject: [PATCH] read-cache: fix memleak

`ce` is allocated in make_cache_entry and should be freed if it is not used any more. refresh_cache_entry as a wrapper around refresh_cache_ent will either return

 - the `ce` given as the parameter, when it was up-to-date;
 - a new updated cache entry which is allocated to new memory; or
 - a NULL when refreshing failed.

In the latter two cases, the original cache-entry `ce` is not used and needs to be freed. The rule can be expressed as "if the return value from refresh is different from the original ce, ce is no longer used."

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 read-cache.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/read-cache.c b/read-cache.c
index 5b922fd5..0052b72 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -748,12 +748,9 @@ struct cache_entry *make_cache_entry(unsigned int mode,
 	ce->ce_mode = create_ce_mode(mode);
 
 	ret = refresh_cache_entry(ce, refresh_options);
-	if (!ret) {
+	if (ret != ce)
 		free(ce);
-		return NULL;
-	} else {
-		return ret;
-	}
+	return ret;
 }
 
 int ce_same_name(const struct cache_entry *a, const struct cache_entry *b)
-- 
2.3.3-454-g85aa98f
Previous: Junio C HamanoNext: Stefan Beller
Message 8 of 44 in “Fixing memory leaks”
  1. 00/15 Fixing memory leaksStefan Beller, Mar 21, 2015
  2. 01/15 read-cache: fix memleakStefan Beller, Mar 21, 2015
  3. Junio C HamanoMar 21, 2015
  4. Stefan BellerMar 23, 2015
  5. 1/2 read-cache: fix memleakStefan Beller, Mar 23, 2015
  6. 2/2 read-cache.c: fix a memleak in add_to_indexStefan Beller, Mar 23, 2015
  7. Junio C HamanoMar 23, 2015
  8. Junio C HamanoMar 23, 2015
  9. 02/15 read-cache: Improve readabilityStefan Beller, Mar 21, 2015
  10. Junio C HamanoMar 21, 2015
  11. Stefan BellerMar 21, 2015
  12. Junio C HamanoMar 22, 2015
  13. 03/15 read-cache: free cache entry in add_to_index in case of early returnStefan Beller, Mar 21, 2015
  14. Junio C HamanoMar 21, 2015
  15. Stefan BellerMar 21, 2015
  16. Junio C HamanoMar 22, 2015
  17. 04/15 update-index: fix a memleakStefan Beller, Mar 21, 2015
  18. Junio C HamanoMar 21, 2015
  19. update-index: Don't copy memory aroundStefan Beller, Mar 23, 2015
  20. Junio C HamanoMar 23, 2015
  21. 05/15 builtin/apply.c: fix a memleakStefan Beller, Mar 21, 2015
  22. Junio C HamanoMar 21, 2015
  23. builtin/apply.c: fix a memleak (Fixup, squashable)Stefan Beller, Mar 23, 2015
  24. Junio C HamanoMar 23, 2015
  25. 06/15 merge-blobs.c: Fix a memleakStefan Beller, Mar 21, 2015
  26. 07/15 merge-recursive: fix memleaksStefan Beller, Mar 21, 2015
  27. Junio C HamanoMar 21, 2015
  28. 08/15 http-push: Remove unneeded cleanupStefan Beller, Mar 21, 2015
  29. 09/15 http: release the memory of a http pack request as wellStefan Beller, Mar 21, 2015
  30. Junio C HamanoMar 22, 2015
  31. Stefan BellerMar 24, 2015
  32. Junio C HamanoMar 24, 2015
  33. 10/15 commit.c: fix a memory leakStefan Beller, Mar 21, 2015
  34. Junio C HamanoMar 21, 2015
  35. Duy NguyenMar 24, 2015
  36. Re* [PATCH 10/15] commit.c: fix a memory leakJunio C Hamano, Mar 24, 2015
  37. Stefan BellerMar 24, 2015
  38. 11/15 builtin/check-attr: fix a memleakStefan Beller, Mar 21, 2015
  39. Junio C HamanoMar 21, 2015
  40. 12/15 builtin/merge-base: fix memleakStefan Beller, Mar 21, 2015
  41. 13/15 builtin/unpack-file: fix a memleakStefan Beller, Mar 21, 2015
  42. 14/15 builtin/cat-file: free memleakStefan Beller, Mar 21, 2015
  43. 15/15 ls-files: fix a memleakStefan Beller, Mar 21, 2015
  44. Junio C HamanoMar 21, 2015

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