(nuttx) branch releases/13.0 updated: arch/arm/gd32f4: fix NULL pointer dereference in arm_earlyserialinit.

[lupyuen]

This is an automated email from the ASF dual-hosted git repository.

lupyuen pushed a commit to branch releases/13.0
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/releases/13.0 by this push:
     new c6e36a4a8ba arch/arm/gd32f4: fix NULL pointer dereference in 
arm_earlyserialinit.
c6e36a4a8ba is described below

commit c6e36a4a8ba5071ad585c45dec6a15271e5848cc
Author: lccosy <1191294...@qq.com>
AuthorDate: Thu Jun 4 23:01:09 2026 +0800

    arch/arm/gd32f4: fix NULL pointer dereference in arm_earlyserialinit.
    
    Add NULL check for g_uart_devs[i] before accessing ->priv in
    arm_earlyserialinit() loop. When a USART is not enabled in defconfig,
    g_uart_devs[i] is NULL, causing a HardFault crash during early boot.
    
    The bug occurs because the original code only checked g_uart_devs[i]->priv
    without first verifying g_uart_devs[i] is not NULL. On Cortex-M4, NULL
    pointer dereference reads from Flash vector table (0x00000000 maps to
    0x08000000), returning a function pointer that causes BusFault when
    written to.
    
    This fix matches the existing NULL check pattern used in arm_serialinit()
    at line 2835 of the same file.
    
    Tested on mplant-gd32f450 board with only USART5 enabled in defconfig.
    Before fix: HardFault at boot (IPSR=3, PC=0x080003e0)
    After fix: System boots normally to NSH Shell
    
    Signed-off-by: lccosy <1191294...@qq.com>
---
 arch/arm/src/gd32f4/gd32f4xx_serial.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/src/gd32f4/gd32f4xx_serial.c 
b/arch/arm/src/gd32f4/gd32f4xx_serial.c
index f4a3659721d..7291a9dceec 100644
--- a/arch/arm/src/gd32f4/gd32f4xx_serial.c
+++ b/arch/arm/src/gd32f4/gd32f4xx_serial.c
@@ -2763,7 +2763,7 @@ void arm_earlyserialinit(void)
 
   for (i = 0; i < GD32_NUSART; i++)
     {
-      if (g_uart_devs[i]->priv)
+      if (g_uart_devs[i] && g_uart_devs[i]->priv)
         {
           up_disableusartint(g_uart_devs[i]->priv, 0);
         }