From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: gregkh@linuxfoundation.org
Cc: linux-kernel@vger.kernel.org,
Colin Ian King <colin.king@canonical.com>,
Douglas Anderson <dianders@chromium.org>,
Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Subject: [PATCH 07/10] nvmem: core: Fix unintentional sign extension issue
Date: Tue, 30 Mar 2021 12:12:38 +0100 [thread overview]
Message-ID: <20210330111241.19401-8-srinivas.kandagatla@linaro.org> (raw)
In-Reply-To: <20210330111241.19401-1-srinivas.kandagatla@linaro.org>
From: Colin Ian King <colin.king@canonical.com>
The shifting of the u8 integer buf[3] by 24 bits to the left will
be promoted to a 32 bit signed int and then sign-extended to a
u64. In the event that the top bit of buf[3] is set then all
then all the upper 32 bits of the u64 end up as also being set
because of the sign-extension. Fix this by casting buf[i] to
a u64 before the shift.
Addresses-Coverity: ("Unintended sign extension")
Fixes: 097eb1136ebb ("nvmem: core: Add functions to make number reading easy")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
drivers/nvmem/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 635e3131eb5f..bca671ff4e54 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -1693,7 +1693,7 @@ int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id,
/* Copy w/ implicit endian conversion */
*val = 0;
for (i = 0; i < len; i++)
- *val |= buf[i] << (8 * i);
+ *val |= (uint64_t)buf[i] << (8 * i);
kfree(buf);
--
2.21.0
next prev parent reply other threads:[~2021-03-30 11:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 11:12 [PATCH 00/10] nvmem: patches (set 1) for 5.13 Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 01/10] dt-bindings: nvmem: mediatek: add support for MediaTek mt8192 SoC Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 02/10] nvmem: convert comma to semicolon Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 03/10] drivers: nvmem: Fix voltage settings for QTI qfprom-efuse Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 04/10] dt-bindings: nvmem: add Broadcom's NVRAM Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 05/10] nvmem: brcm_nvram: new driver exposing " Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 06/10] nvmem: core: Add functions to make number reading easy Srinivas Kandagatla
2021-03-30 11:12 ` Srinivas Kandagatla [this message]
2021-03-30 11:12 ` [PATCH 08/10] nvmem: rmem: fix undefined reference to memremap Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 09/10] dt-bindings: nvmem: Add SoC compatible for sc7280 Srinivas Kandagatla
2021-03-30 11:12 ` [PATCH 10/10] nvmem: qfprom: Add support for fuse blowing on sc7280 Srinivas Kandagatla
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