1 files changed, 34 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.10/803-v5.13-0005-nvmem-core-Fix-unintentional-sign-extension-issue.patch b/target/linux/generic/backport-5.10/803-v5.13-0005-nvmem-core-Fix-unintentional-sign-extension-issue.patch
new file mode 100644
index 0000000000..72133d3a35
--- /dev/null
+++ b/target/linux/generic/backport-5.10/803-v5.13-0005-nvmem-core-Fix-unintentional-sign-extension-issue.patch
@@ -0,0 +1,34 @@
+From 55022fdeace8e432f008787ce03703bdcc9c3ca9 Mon Sep 17 00:00:00 2001
+From: Colin Ian King <colin.king@canonical.com>
+Date: Tue, 30 Mar 2021 12:12:38 +0100
+Subject: [PATCH] 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>
+---
+ drivers/nvmem/core.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/nvmem/core.c
++++ b/drivers/nvmem/core.c
+@@ -1699,7 +1699,7 @@ int nvmem_cell_read_variable_le_u64(stru
+ 	/* 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);
+