From cb6b0a393c4a6d43e29ef476d19313c5fef8b6c7 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Sun, 18 Aug 2019 10:33:42 +0100 Subject: [PATCH] nvmem: meson-mx-efuse: allow reading data smaller than word_size Some Amlogic boards store the Ethernet MAC address inside the eFuse. The Ethernet MAC address uses 6 bytes. The existing logic in meson_mx_efuse_read() would write beyond the end of the data buffer when trying to read data with a size that is not aligned to word_size (4 bytes on Meson8, Meson8b and Meson8m2). Calculate the remaining data to copy inside meson_mx_efuse_read() so reading 6 bytes doesn't write beyond the end of the data buffer. Signed-off-by: Martin Blumenstingl Reviewed-by: Neil Armstrong Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20190818093345.29647-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/meson-mx-efuse.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvmem/meson-mx-efuse.c b/drivers/nvmem/meson-mx-efuse.c index b9f9ce089de9..07c9f38c1c60 100644 --- a/drivers/nvmem/meson-mx-efuse.c +++ b/drivers/nvmem/meson-mx-efuse.c @@ -155,7 +155,8 @@ static int meson_mx_efuse_read(void *context, unsigned int offset, if (err) break; - memcpy(buf + i, &tmp, efuse->config.word_size); + memcpy(buf + i, &tmp, + min_t(size_t, bytes - i, efuse->config.word_size)); } meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1,