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From: "Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
To: git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>,
	"Michael Haggerty" <mhagger@alum.mit.edu>,
	"Stefan Beller" <sbeller@google.com>,
	"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
Subject: [PATCH v4 1/5] environment.c: fix potential segfault by get_git_common_dir()
Date: Tue,  4 Apr 2017 17:21:19 +0700	[thread overview]
Message-ID: <20170404102123.25315-2-pclouds@gmail.com> (raw)
In-Reply-To: <20170404102123.25315-1-pclouds@gmail.com>

setup_git_env() must be called before this function to initialize
git_common_dir so that it returns a non NULL string. And it must return
a non NULL string or segfault can happen because all callers expect so.

It does not do so explicitly though and depends on get_git_dir() being
called first (which will guarantee setup_git_env()). Avoid this
dependency and call setup_git_env() by itself.

test-ref-store.c will hit this problem because it's very lightweight,
just enough initialization to exercise refs code, and get_git_dir() will
never be called until get_worktrees() is, which uses get_git_common_dir
and hits a segfault.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 environment.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/environment.c b/environment.c
index 42dc3106d2..2986ee7200 100644
--- a/environment.c
+++ b/environment.c
@@ -214,6 +214,8 @@ const char *get_git_dir(void)
 
 const char *get_git_common_dir(void)
 {
+	if (!git_dir)
+		setup_git_env();
 	return git_common_dir;
 }
 
-- 
2.11.0.157.gd943d85


  reply	other threads:[~2017-04-04 10:21 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-08 11:31 [PATCH RFC 0/2] Kill manual ref parsing code in worktree.c Nguyễn Thái Ngọc Duy
2017-02-08 11:31 ` [PATCH 1/2] refs.c: add resolve_ref_submodule() Nguyễn Thái Ngọc Duy
2017-02-09  5:20   ` Michael Haggerty
2017-02-08 11:31 ` [PATCH 2/2] worktree.c: use submodule interface to access refs from another worktree Nguyễn Thái Ngọc Duy
2017-02-08 19:50   ` Stefan Beller
2017-02-08 23:19     ` Junio C Hamano
2017-02-08 23:25   ` Junio C Hamano
2017-02-09  6:07   ` Michael Haggerty
2017-02-09  6:55     ` Junio C Hamano
2017-02-09  8:04       ` Michael Haggerty
2017-02-09 11:59     ` Duy Nguyen
2017-02-09 14:03       ` Michael Haggerty
2017-02-08 18:18 ` [PATCH RFC 0/2] Kill manual ref parsing code in worktree.c Junio C Hamano
2017-02-16 12:02 ` [PATCH v2 0/5] " Nguyễn Thái Ngọc Duy
2017-02-16 12:02   ` [PATCH v2 1/5] refs: introduce get_worktree_ref_store() Nguyễn Thái Ngọc Duy
2017-02-16 12:02   ` [PATCH v2 2/5] refs.c: add refs_resolve_ref_unsafe() Nguyễn Thái Ngọc Duy
2017-02-16 12:03   ` [PATCH v2 3/5] worktree.c: kill parse_ref() in favor of refs_resolve_ref_unsafe() Nguyễn Thái Ngọc Duy
2017-02-16 12:03   ` [PATCH v2 4/5] refs: add refs_create_symref() Nguyễn Thái Ngọc Duy
2017-02-16 12:03   ` [PATCH v2 5/5] refs: kill set_worktree_head_symref() Nguyễn Thái Ngọc Duy
2017-03-18 10:02   ` [PATCH v3 0/4] Kill manual ref parsing code in worktree.c Nguyễn Thái Ngọc Duy
2017-03-18 10:02     ` [PATCH v3 1/4] environment.c: fix potential segfault by get_git_common_dir() Nguyễn Thái Ngọc Duy
2017-03-18 17:54       ` Junio C Hamano
2017-03-19  9:34         ` Duy Nguyen
2017-03-18 10:02     ` [PATCH v3 2/4] refs: introduce get_worktree_ref_store() Nguyễn Thái Ngọc Duy
2017-03-20  6:59       ` Michael Haggerty
2017-03-20 12:01         ` Duy Nguyen
2017-03-20 14:25           ` Michael Haggerty
2017-03-26  8:26             ` Duy Nguyen
2017-03-18 10:02     ` [PATCH v3 3/4] worktree.c: kill parse_ref() in favor of refs_resolve_ref_unsafe() Nguyễn Thái Ngọc Duy
2017-03-18 10:02     ` [PATCH v3 4/4] refs: kill set_worktree_head_symref() Nguyễn Thái Ngọc Duy
2017-03-18 17:49     ` [PATCH v3 0/4] Kill manual ref parsing code in worktree.c Junio C Hamano
2017-04-04 10:21     ` [PATCH v4 0/5] " Nguyễn Thái Ngọc Duy
2017-04-04 10:21       ` Nguyễn Thái Ngọc Duy [this message]
2017-04-04 10:21       ` [PATCH v4 2/5] refs.c: make submodule ref store hashmap generic Nguyễn Thái Ngọc Duy
2017-04-04 10:21       ` [PATCH v4 3/5] refs: introduce get_worktree_ref_store() Nguyễn Thái Ngọc Duy
2017-04-22  4:52         ` Michael Haggerty
2017-04-04 10:21       ` [PATCH v4 4/5] worktree.c: kill parse_ref() in favor of refs_resolve_ref_unsafe() Nguyễn Thái Ngọc Duy
2017-04-04 10:21       ` [PATCH v4 5/5] refs: kill set_worktree_head_symref() Nguyễn Thái Ngọc Duy
2017-04-14  1:40       ` [PATCH v4 0/5] Kill manual ref parsing code in worktree.c Junio C Hamano
2017-04-14  2:02         ` Junio C Hamano
2017-04-14 12:45           ` Duy Nguyen
2017-04-17  1:36             ` Junio C Hamano
2017-04-22  5:06         ` Michael Haggerty
2017-04-24 10:01       ` [PATCH v5 0/6] " Nguyễn Thái Ngọc Duy
2017-04-24 10:01         ` [PATCH v5 1/6] environment.c: fix potential segfault by get_git_common_dir() Nguyễn Thái Ngọc Duy
2017-04-24 10:01         ` [PATCH v5 2/6] refs.c: make submodule ref store hashmap generic Nguyễn Thái Ngọc Duy
2017-04-24 10:01         ` [PATCH v5 3/6] refs: add REFS_STORE_ALL_CAPS Nguyễn Thái Ngọc Duy
2017-04-24 10:01         ` [PATCH v5 4/6] refs: introduce get_worktree_ref_store() Nguyễn Thái Ngọc Duy
2017-04-24 10:01         ` [PATCH v5 5/6] worktree.c: kill parse_ref() in favor of refs_resolve_ref_unsafe() Nguyễn Thái Ngọc Duy
2017-04-24 10:01         ` [PATCH v5 6/6] refs: kill set_worktree_head_symref() Nguyễn Thái Ngọc Duy
2017-04-25  4:30         ` [PATCH v5 0/6] Kill manual ref parsing code in worktree.c Junio C Hamano

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