From: John Thomson <g...@johnthomson.fastmail.com.au>

Verify data size before trying to parse it to avoid reading out of
buffer. This could happen in case of problems at MTD level or invalid DT
bindings.

Signed-off-by: John Thomson <g...@johnthomson.fastmail.com.au>
Fixes: d5542923f200 ("nvmem: add driver handling U-Boot environment variables")
[rmilecki: simplify commit description & rebase]
Signed-off-by: Rafał Miłecki <ra...@milecki.pl>
---
V2: New patch in the series

 drivers/nvmem/u-boot-env.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c
index 936e39b20b38..593f0bf4a395 100644
--- a/drivers/nvmem/u-boot-env.c
+++ b/drivers/nvmem/u-boot-env.c
@@ -176,6 +176,13 @@ static int u_boot_env_parse(struct u_boot_env *priv)
                data_offset = offsetof(struct u_boot_env_image_broadcom, data);
                break;
        }
+
+       if (dev_size < data_offset) {
+               dev_err(dev, "Device too small for u-boot-env\n");
+               err = -EIO;
+               goto err_kfree;
+       }
+
        crc32_addr = (__le32 *)(buf + crc32_offset);
        crc32 = le32_to_cpu(*crc32_addr);
        crc32_data_len = dev_size - crc32_data_offset;
-- 
2.35.3

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