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authorColin Ian King <colin.king@canonical.com>2021-03-30 12:12:38 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-04-02 16:28:03 +0200
commit55022fdeace8e432f008787ce03703bdcc9c3ca9 (patch)
tree8b2df42f0964fcaf2d6c6bf80a32ce3c2020fff3 /drivers/nvmem
parenta28e824fb8270eda43fd0f65c2a5fdf33f55c5eb (diff)
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nvmem: core: Fix unintentional sign extension issue
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. Fixes: a28e824fb827 ("nvmem: core: Add functions to make number reading easy") Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Addresses-Coverity: ("Unintended sign extension") Link: https://lore.kernel.org/r/20210330111241.19401-8-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/nvmem')
-rw-r--r--drivers/nvmem/core.c2
1 files changed, 1 insertions, 1 deletions
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);