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From: Jan Remmet <j.remmet@phytec.de>
To: barebox@lists.infradead.org
Subject: [PATCH v2] common: state: check length
Date: Thu, 23 May 2019 09:49:00 +0200	[thread overview]
Message-ID: <1558597740-86748-1-git-send-email-j.remmet@phytec.de> (raw)
In-Reply-To: <20190523065712.isc4cdwsnbqvmtf7@pengutronix.de>

if written_length is read from a partial written bucket it may be to
big and xmalloc will panic barebox.

Check if the value is sane. Make read_len unsigned to avoid negative
values.

Signed-off-by: Jan Remmet <j.remmet@phytec.de>
---
v2: replace compare < 0 by making read_len unsigned

 common/state/backend_bucket_direct.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/common/state/backend_bucket_direct.c b/common/state/backend_bucket_direct.c
index 95ddb9310685..0dbd334db821 100644
--- a/common/state/backend_bucket_direct.c
+++ b/common/state/backend_bucket_direct.c
@@ -52,7 +52,7 @@ static int state_backend_bucket_direct_read(struct state_backend_storage_bucket
 	struct state_backend_storage_bucket_direct *direct =
 	    get_bucket_direct(bucket);
 	struct state_backend_storage_bucket_direct_meta meta;
-	ssize_t read_len;
+	uint32_t read_len;
 	void *buf;
 	int ret;
 
@@ -67,6 +67,11 @@ static int state_backend_bucket_direct_read(struct state_backend_storage_bucket
 	}
 	if (meta.magic == direct_magic) {
 		read_len = meta.written_length;
+		if (read_len > direct->max_size) {
+			dev_err(direct->dev, "Wrong length in meta data\n");
+			return -EINVAL;
+
+		}
 	} else {
 		if (meta.magic != ~0 && !!meta.magic)
 			bucket->wrong_magic = 1;
-- 
2.7.4


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  reply	other threads:[~2019-05-23  7:49 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-21 14:44 [PATCH] " Jan Remmet
2019-05-23  6:57 ` Sascha Hauer
2019-05-23  7:49   ` Jan Remmet [this message]
2019-05-23  8:00     ` [PATCH v2] " Sascha Hauer

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