From: Jeff King <peff@peff.net>
To: Andrey Okoshkin <a.okoshkin@samsung.com>
Cc: gitster@pobox.com, git@vger.kernel.org, pclouds@gmail.com,
l.s.r@web.de, avarab@gmail.com, krh@redhat.com,
rctay89@gmail.com, Ivan Arishchenko <i.arishchenk@samsung.com>,
Mikhail Labiuk <m.labiuk@samsung.com>
Subject: [PATCH 3/4] log: handle broken HEAD in decoration check
Date: Thu, 19 Oct 2017 13:49:01 -0400 [thread overview]
Message-ID: <20171019174900.4a5qypeabbt4mgwc@sigill.intra.peff.net> (raw)
In-Reply-To: <20171019174452.hd3c47ocducddvgr@sigill.intra.peff.net>
The resolve_ref_unsafe() function may return NULL even with
a REF_ISSYMREF flag if a symref points to a broken ref. As a
result, it's possible for the decoration code's "is this
branch the current HEAD" check to segfault when it passes
the NULL to starts_with().
This is unlikely in practice, since we can only reach this
code if we already resolved HEAD to a matching sha1 earlier.
But it's possible if HEAD racily becomes broken, or if
there's a transient filesystem error.
We can fix this by returning early in the broken case, since
NULL could not possibly match any of our branch names.
Signed-off-by: Jeff King <peff@peff.net>
---
log-tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/log-tree.c b/log-tree.c
index cea056234d..580b3a98a0 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -198,7 +198,7 @@ static const struct name_decoration *current_pointed_by_HEAD(const struct name_d
/* Now resolve and find the matching current branch */
branch_name = resolve_ref_unsafe("HEAD", 0, NULL, &rru_flags);
- if (!(rru_flags & REF_ISSYMREF))
+ if (!branch_name || !(rru_flags & REF_ISSYMREF))
return NULL;
if (!starts_with(branch_name, "refs/"))
--
2.15.0.rc1.560.g5f0609e481
next prev parent reply other threads:[~2017-10-19 17:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20171018170047epcas2p4310be357e11e194d6d08ac3bdc478ba3@epcas2p4.samsung.com>
2017-10-18 17:00 ` [PATCH] commit: check result of resolve_ref_unsafe Andrey Okoshkin
2017-10-18 18:34 ` Jeff King
2017-10-19 0:41 ` Junio C Hamano
2017-10-19 2:49 ` Jeff King
2017-10-19 9:33 ` Andrey Okoshkin
2017-10-19 9:36 ` [PATCH v2] " Andrey Okoshkin
2017-10-19 17:44 ` Jeff King
2017-10-19 17:46 ` [PATCH 1/4] test-ref-store: avoid passing NULL to printf Jeff King
2017-10-19 17:47 ` [PATCH 2/4] remote: handle broken symrefs Jeff King
2017-10-19 17:53 ` Jeff King
2017-10-19 17:49 ` Jeff King [this message]
2017-10-19 17:49 ` [PATCH 4/4] worktree: handle broken symrefs in find_shared_symref() Jeff King
2017-10-21 10:49 ` Eric Sunshine
2017-10-21 19:26 ` Jeff King
2017-10-22 0:46 ` Junio C Hamano
2017-10-20 10:40 ` [PATCH v2] commit: check result of resolve_ref_unsafe Andrey Okoshkin
2017-10-20 11:03 ` [PATCH v3] " Andrey Okoshkin
2017-10-20 13:09 ` [PATCH v4] " Andrey Okoshkin
2017-10-21 6:19 ` Jeff King
2017-10-22 0:46 ` Junio C Hamano
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