On 8/1/2024 22:38, Ma Ke wrote:

In altr_s10_sdram_check_ecc_deps(), of_get_address() may return NULL which is later dereferenced. Fix this bug by adding NULL check.

Only of_get_address() has been mentioned here but the patch also tries to fix a possible NULL pointer dereference arising from of_translate_address(). Also, a some context on how this was discovered might be helpful.

Cc: stable@vger.kernel.org Fixes: e1bca853dddc ("EDAC/altera: Add SDRAM ECC check for U-Boot") Signed-off-by: Ma Ke make24@iscas.ac.cn

---

drivers/edac/altera_edac.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c index fe89f5c4837f..d6bf0eebeb41 100644 --- a/drivers/edac/altera_edac.c +++ b/drivers/edac/altera_edac.c @@ -1086,6 +1086,7 @@ static int altr_s10_sdram_check_ecc_deps(struct altr_edac_device_dev *device) struct arm_smccc_res result; struct device_node *np; phys_addr_t sdram_addr;

• const __be32 *sdram_addrp; u32 read_reg; int ret;

@@ -1093,8 +1094,14 @@ static int altr_s10_sdram_check_ecc_deps(struct altr_edac_device_dev *device) if (!np) goto sdram_err;

• sdram_addr = of_translate_address(np, of_get_address(np, 0,

• 					     NULL, NULL));
  

• sdram_addrp = of_get_address(np, 0, NULL, NULL);
• if (!sdram_addrp)

• return -EINVAL;
  

• sdram_addr = of_translate_address(np, sdram_addrp);
• if (!sdram_addr)

• return -EINVAL;
  

Will sdram_addr here ever be NULL? IIUC, of_translate_address() will return OF_BAD_ADDR in case the translation fails. Perhaps, a more prudent check here, if required, would be

if (sdram_addr == OF_BAD_ADDR)