From: Pavel Machek <pavel@denx.de>
To: alexander.shishkin@linux.intel.com, security@kernel.org,
sasha.levin@oracle.com, gregkh@linuxfoundation.org,
kernel list <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@osdl.org>,
trivial@kernel.org
Subject: stm class: Prevent user-controllable allocations
Date: Tue, 7 May 2019 14:41:13 +0200 [thread overview]
Message-ID: <20190507124113.GA659@amd> (raw)
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It seems to me that we still allow overflow if count == ~0. We'll then
allocate 0 bytes but copy ~0 bytes. That does not sound healthy.
Fixes: f08b18266c7116e2ec6885dd53a928f580060a71
Signed-off-by: Pavel Machek <pavel@denx.de>
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index c7ba8ac..8846fca 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -631,7 +631,7 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf,
char *kbuf;
int err;
- if (count + 1 > PAGE_SIZE)
+ if (count > PAGE_SIZE - 1)
count = PAGE_SIZE - 1;
/*
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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next reply other threads:[~2019-05-07 12:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-07 12:41 Pavel Machek [this message]
2019-05-07 12:50 ` stm class: Prevent user-controllable allocations Dan Carpenter
2019-05-07 15:11 ` Pavel Machek
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