linux-kernel - [PATCH v2] lib/stackdepot.c: allow the stack trace hash to be zero

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1460549245-131634-1-git-send-email-glider@google.com>
Date:	Wed, 13 Apr 2016 14:07:25 +0200
From:	Alexander Potapenko <glider@...gle.com>
To:	adech.fo@...il.com, dvyukov@...gle.com, cl@...ux.com,
	akpm@...ux-foundation.org, ryabinin.a.a@...il.com, kcc@...gle.com,
	iamjoonsoo.kim@....com
Cc:	kasan-dev@...glegroups.com, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
Subject: [PATCH v2] lib/stackdepot.c: allow the stack trace hash to be zero

Do not bail out from depot_save_stack() if the stack trace has zero hash.
Initially depot_save_stack() silently dropped stack traces with zero
hashes, however there's actually no point in reserving this zero value.

Reported-by: Joonsoo Kim <iamjoonsoo.kim@....com>
Signed-off-by: Alexander Potapenko <glider@...gle.com>
---
 lib/stackdepot.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 654c9d8..9e0b031 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -210,10 +210,6 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace,
 		goto fast_exit;
 
 	hash = hash_stack(trace->entries, trace->nr_entries);
-	/* Bad luck, we won't store this stack. */
-	if (hash == 0)
-		goto exit;
-
 	bucket = &stack_table[hash & STACK_HASH_MASK];
 
 	/*
-- 
2.8.0.rc3.226.g39d4020