list_debug: check prev/next for NULL when checking list_head for validity

PATCH New Ronnie Sahlberg 1 participant 1 message Jan 10, 2018

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Library code SMB client (CIFS) Kernel SMB3 server (ksmbd)

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Ronnie Sahlberg

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2018-01-10 03:07 UTC #0 lore raw

PATCH 1/1 list_debug: check prev/next for NULL when checking list_head for validity

Signed-off-by Ronnie Sahlberg <[email protected]>

---
 lib/list_debug.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

lib/list_debug.c +7 -1

index a34db8d27667..e33947f06d84 100644
@@ -42,7 +42,13 @@ bool __list_del_entry_valid(struct list_head *entry)
 	prev = entry->prev;
 	next = entry->next;
 
-	if (CHECK_DATA_CORRUPTION(next == LIST_POISON1,
+	if (CHECK_DATA_CORRUPTION(next == NULL,
+			"list_del corruption, %p->next is NULL\n",
+			entry) ||
+	    CHECK_DATA_CORRUPTION(prev == NULL,
+			"list_del corruption, %p->prev is NULL\n",
+			entry) ||
+	    CHECK_DATA_CORRUPTION(next == LIST_POISON1,
 			"list_del corruption, %p->next is LIST_POISON1 (%p)\n",
 			entry, LIST_POISON1) ||
 	    CHECK_DATA_CORRUPTION(prev == LIST_POISON2,

Signature · 1 line

2.13.3