linux-kernel - [PATCH next] i2c: Fix end of loop test in i2c_atr_find_mapping_by

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: <aAii_iawJdptQyCt@stanley.mountain>
Date: Wed, 23 Apr 2025 11:21:18 +0300
From: Dan Carpenter <dan.carpenter@...aro.org>
To: Romain Gantois <romain.gantois@...tlin.com>
Cc: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>,
	Luca Ceresoli <luca.ceresoli@...tlin.com>,
	Wolfram Sang <wsa+renesas@...g-engineering.com>,
	Andi Shyti <andi.shyti@...nel.org>, linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: [PATCH next] i2c: Fix end of loop test in
 i2c_atr_find_mapping_by_addr()

When the list_for_each_entry_reverse() exits without hitting a break
then the list cursor points to invalid memory.  So this check for
if (c2a->fixed) is checking bogus memory.  Fix it by using a "found"
variable to track if we found what we were looking for or not.

Fixes: c3f55241882b ("i2c: Support dynamic address translation")
Signed-off-by: Dan Carpenter <dan.carpenter@...aro.org>
---
 drivers/i2c/i2c-atr.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c
index d5aa6738370c..1aeaecacc26c 100644
--- a/drivers/i2c/i2c-atr.c
+++ b/drivers/i2c/i2c-atr.c
@@ -240,6 +240,7 @@ i2c_atr_find_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr)
 	struct i2c_atr *atr = chan->atr;
 	struct i2c_atr_alias_pair *c2a;
 	struct list_head *alias_pairs;
+	bool found = false;
 	u16 alias;
 	int ret;
 
@@ -258,11 +259,14 @@ i2c_atr_find_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr)
 		if (unlikely(list_empty(alias_pairs)))
 			return NULL;
 
-		list_for_each_entry_reverse(c2a, alias_pairs, node)
-			if (!c2a->fixed)
+		list_for_each_entry_reverse(c2a, alias_pairs, node) {
+			if (!c2a->fixed) {
+				found = true;
 				break;
+			}
+		}
 
-		if (c2a->fixed)
+		if (!found)
 			return NULL;
 
 		atr->ops->detach_addr(atr, chan->chan_id, c2a->addr);
-- 
2.47.2