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 | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 89da2cf2c969..00502ffe9b4a 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3365,7 +3365,9 @@ 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)
+ if (buff_len < param_offset)
+ param_size = 0;
+ else if (param_offset + param_size > buff_len)
param_size = buff_len - param_offset;
memcpy(param_read_buf, &desc_buf[param_offset], param_size);
}
