From 0d0659c78d7ea29ad6c3c538dcaae0227f31b9d2 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Fri, 4 Jun 2010 16:17:37 -0700 Subject: [PATCH] arch/sparc/kernel: Eliminate what looks like a NULL pointer dereference At the point of the test, action cannot be NULL, as it has been dereferenced in the code just above. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @r exists@ expression E,E1; identifier f; statement S1,S2,S3; @@ if ((E == NULL && ...) || ...) { ... when != if (...) S1 else S2 when != E = E1 * E->f ... when any } else S3 // Signed-off-by: Julia Lawall Signed-off-by: David S. Miller --- arch/sparc/kernel/sun4d_irq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/sparc/kernel/sun4d_irq.c b/arch/sparc/kernel/sun4d_irq.c index ab036a72de5a..e11b4612dabb 100644 --- a/arch/sparc/kernel/sun4d_irq.c +++ b/arch/sparc/kernel/sun4d_irq.c @@ -183,7 +183,7 @@ void sun4d_free_irq(unsigned int irq, void *dev_id) goto out_unlock; } - if (action && tmp) + if (tmp) tmp->next = action->next; else *actionp = action->next;