[PATCH] alpha: add null pointer check

[PATCH] alpha: add null pointer check

[cgel.zte]

From: Lv Ruyi <lv.ruyi@zte.com.cn>

kmalloc is a memory allocation function which can return NULL when some
internal memory errors happen. Add null pointer check to avoid
dereferencing null pointer.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
---
 arch/alpha/kernel/module.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/alpha/kernel/module.c b/arch/alpha/kernel/module.c
index 5b60c248de9e..5442b75a98c2 100644
--- a/arch/alpha/kernel/module.c
+++ b/arch/alpha/kernel/module.c
@@ -47,6 +47,8 @@ process_reloc_for_got(Elf64_Rela *rela,
 		}
 
 	g = kmalloc (sizeof (*g), GFP_KERNEL);
+	if (!g)
+		return;
 	g->next = chains[r_sym].next;
 	g->r_addend = r_addend;
 	g->got_offset = *poffset;
-- 
2.25.1

Re: [PATCH] alpha: add null pointer check

[Al Viro]

On Sat, Apr 02, 2022 at 08:34:36AM +0000, cgel.zte@gmail.com wrote:
> From: Lv Ruyi <lv.ruyi@zte.com.cn>
> 
> kmalloc is a memory allocation function which can return NULL when some
> internal memory errors happen. Add null pointer check to avoid
> dereferencing null pointer.

Why is that fix correct?  The only caller (module_frob_arch_sections())
has no way to tell we'd failed.  _IF_ ignoring the failure is the right
thing to do, the analysis needs to be covered in commit message.