From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= Subject: [PATCH] unpack_entry: invalidate newly added cache entry in case of error Date: Tue, 30 Apr 2013 09:29:52 +0700 Message-ID: <1367288992-14979-1-git-send-email-pclouds@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Junio C Hamano , Thomas Rast , =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Tue Apr 30 04:29:15 2013 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1UX0Jd-0002xx-5F for gcvg-git-2@plane.gmane.org; Tue, 30 Apr 2013 04:29:13 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759875Ab3D3C3H convert rfc822-to-quoted-printable (ORCPT ); Mon, 29 Apr 2013 22:29:07 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:60373 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759543Ab3D3C3G (ORCPT ); Mon, 29 Apr 2013 22:29:06 -0400 Received: by mail-pa0-f53.google.com with SMTP id kx1so76576pab.40 for ; Mon, 29 Apr 2013 19:29:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer:mime-version :content-type:content-transfer-encoding; bh=he0FxksrcWn83j46/rMMeHc+vaPt5FsIdLnRhAHd+Lw=; b=OVi8m+BaDwnuaFvXTSCycJ2/uRI5be/x+FtYUgfiB0RW54zADXVPqrjHx96XTJ8hZQ 7hklNyzpF4AZbQ+6J3P734eDwMbHQs0E6PeQ8eRU7kB/aUJBv9N6JeUWo24yknO7u9PM OHU1qVYWAs1BoTbs+0goAzOchQ5zpE6pkCaBA/cRaEULngOCTsw1QnMj0zjKjiiNCe12 AThbOQLzBeAsB5XSGl/jVvHMN/TxqQo3NixMtNUo0UnTwee4oLRm/oymPxi4Urm9JL1E ybJ6+k+Ra7p0ruPsGEwlMlcFJCFpvkLk77Uk5CTi8pfzfhSW4OsbruJ5g6qTGvNo7u4W Sjxg== X-Received: by 10.68.138.7 with SMTP id qm7mr75325258pbb.169.1367288945240; Mon, 29 Apr 2013 19:29:05 -0700 (PDT) Received: from lanh ([115.74.52.135]) by mx.google.com with ESMTPSA id ze11sm28319541pab.22.2013.04.29.19.29.01 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 29 Apr 2013 19:29:04 -0700 (PDT) Received: by lanh (sSMTP sendmail emulation); Tue, 30 Apr 2013 09:29:54 +0700 X-Mailer: git-send-email 1.8.2.83.gc99314b Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: In this particular code path, we add "base" to the delta base cache. Then decide to free it, but we forgot about a dangling pointer in the cache. Invalidate that entry when we free "base". Signed-off-by: Nguy=E1=BB=85n Th=C3=A1i Ng=E1=BB=8Dc Duy --- Some of my changes triggered a double free fault at "free(base);" in t5303. This looks like a correct thing to do, but I may be missing something (I'm not even sure how it happened). Please check. sha1_file.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/sha1_file.c b/sha1_file.c index 64228a2..99ead7c 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -1912,7 +1912,8 @@ void clear_delta_base_cache(void) release_delta_base_cache(&delta_base_cache[p]); } =20 -static void add_delta_base_cache(struct packed_git *p, off_t base_offs= et, +static struct delta_base_cache_entry * +add_delta_base_cache(struct packed_git *p, off_t base_offset, void *base, unsigned long base_size, enum object_type type) { unsigned long hash =3D pack_entry_hash(p, base_offset); @@ -1947,6 +1948,7 @@ static void add_delta_base_cache(struct packed_gi= t *p, off_t base_offset, ent->lru.prev =3D delta_base_cache_lru.prev; delta_base_cache_lru.prev->next =3D &ent->lru; delta_base_cache_lru.prev =3D &ent->lru; + return ent; } =20 static void *read_object(const unsigned char *sha1, enum object_type *= type, @@ -2086,12 +2088,13 @@ void *unpack_entry(struct packed_git *p, off_t = obj_offset, void *delta_data; void *base =3D data; unsigned long delta_size, base_size =3D size; + struct delta_base_cache_entry *ent =3D NULL; int i; =20 data =3D NULL; =20 if (base) - add_delta_base_cache(p, obj_offset, base, base_size, type); + ent =3D add_delta_base_cache(p, obj_offset, base, base_size, type); =20 if (!base) { /* @@ -2129,6 +2132,8 @@ void *unpack_entry(struct packed_git *p, off_t ob= j_offset, "at offset %"PRIuMAX" from %s", (uintmax_t)curpos, p->pack_name); free(base); + if (ent) + ent->data =3D NULL; data =3D NULL; continue; } --=20 1.8.2.83.gc99314b