If param_offset > buff_len then the memcpy() statement in
ufshcd_read_desc_param() corrupts memory since it copies
256 + buff_len - param_offset bytes into a buffer with size buff_len.
Since param_offset < 256 this results in writing past the bound of the
output buffer.
Fixes: cbe193f6f093 ("scsi: ufs: Fix potential NULL pointer access during memcpy")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 064a44e628d6..6c251afe65f9 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3418,9 +3418,11 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
if (is_kmalloc) {
/* Make sure we don't copy more data than available */
- if (param_offset + param_size > buff_len)
- param_size = buff_len - param_offset;
- memcpy(param_read_buf, &desc_buf[param_offset], param_size);
+ if (param_offset >= buff_len)
+ ret = -EINVAL;
+ else
+ memcpy(param_read_buf, &desc_buf[param_offset],
+ min_t(u32, param_size, buff_len - param_offset));
}
out:
if (is_kmalloc)
