[PATCH v2] hw/ufs: Fix mcq register range check logic

[Jeuk Kim]

The function ufs_is_mcq_reg() and ufs_is_mcq_op_reg() only evaluated
the range of the mcq_reg and mcq_op_reg offset, which is defined as
a constant. Therefore, it was possible for them to return true
even though the ufs device is configured to not support the mcq.
This could cause ufs_mmio_read()/ufs_mmio_write() to result in
Null-pointer-dereference.
So fix it.

Resolves: #2428
Fixes: 5c079578d2e4 ("hw/ufs: Add support MCQ of UFSHCI 4.0")
Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Jeuk Kim <jeuk20.kim@samsung.com>
Reviewed-by: Minwoo Im <minwoo.im@samsung.com>
---
 hw/ufs/ufs.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/hw/ufs/ufs.c b/hw/ufs/ufs.c
index 683fff5840..945a0ea127 100644
--- a/hw/ufs/ufs.c
+++ b/hw/ufs/ufs.c
@@ -57,14 +57,26 @@ static inline uint64_t ufs_reg_size(UfsHc *u)
 
 static inline bool ufs_is_mcq_reg(UfsHc *u, uint64_t addr, unsigned size)
 {
-    uint64_t mcq_reg_addr = ufs_mcq_reg_addr(u, 0);
+    uint64_t mcq_reg_addr;
+
+    if (!u->params.mcq) {
+        return false;
+    }
+
+    mcq_reg_addr = ufs_mcq_reg_addr(u, 0);
     return (addr >= mcq_reg_addr &&
             addr + size <= mcq_reg_addr + sizeof(u->mcq_reg));
 }
 
 static inline bool ufs_is_mcq_op_reg(UfsHc *u, uint64_t addr, unsigned size)
 {
-    uint64_t mcq_op_reg_addr = ufs_mcq_op_reg_addr(u, 0);
+    uint64_t mcq_op_reg_addr;
+
+    if (!u->params.mcq) {
+        return false;
+    }
+
+    mcq_op_reg_addr = ufs_mcq_op_reg_addr(u, 0);
     return (addr >= mcq_op_reg_addr &&
             addr + size <= mcq_op_reg_addr + sizeof(u->mcq_op_reg));
 }
-- 
2.34.1