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
WARNING: multiple messages have this Message-ID (diff)
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 -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c
next reply other threads:[~2021-09-05 14:41 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-05 14:40 Len Baker [this message] 2021-09-05 14:40 ` [PATCH] i3c/master/mipi-i3c-hci: Prefer struct_size over open coded arithmetic Len Baker 2021-09-06 4:30 ` Nicolas Pitre 2021-09-06 4:30 ` Nicolas Pitre 2021-09-13 17:39 ` Alexandre Belloni 2021-09-13 17:39 ` Alexandre Belloni
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