From: Len Baker <len.baker@gmx.com>
To: Boris Brezillon <boris.brezillon@collabora.com>,
Nicolas Pitre <npitre@baylibre.com>
Cc: Len Baker <len.baker@gmx.com>, Kees Cook <keescook@chromium.org>,
linux-i3c@lists.infradead.org, linux-hardening@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] i3c/master/mipi-i3c-hci: Prefer struct_size over open coded arithmetic
Date: Sun, 5 Sep 2021 16:40:54 +0200 [thread overview]
Message-ID: <20210905144054.5124-1-len.baker@gmx.com> (raw)
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the struct_size() helper to do the arithmetic instead of the
argument "size + count * size" in the kzalloc() function.
[1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
---
drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index af873a9be050..2990ac9eaade 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -223,7 +223,7 @@ static int hci_dma_init(struct i3c_hci *hci)
}
if (nr_rings > XFER_RINGS)
nr_rings = XFER_RINGS;
- rings = kzalloc(sizeof(*rings) + nr_rings * sizeof(*rh), GFP_KERNEL);
+ rings = kzalloc(struct_size(rings, headers, nr_rings), GFP_KERNEL);
if (!rings)
return -ENOMEM;
hci->io_data = rings;
--
2.25.1
--
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next reply other threads:[~2021-09-07 18:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-05 14:40 Len Baker [this message]
2021-09-06 4:30 ` [PATCH] i3c/master/mipi-i3c-hci: Prefer struct_size over open coded arithmetic Nicolas Pitre
2021-09-13 17:39 ` Alexandre Belloni
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