From 2cdeaba5a1087f0f83e56729ea5c730b498639d9 Mon Sep 17 00:00:00 2001 From: Yizhou Zhao Date: Fri, 29 May 2026 18:50:16 +0800 Subject: [PATCH] appletalk: aarp: zero-initialize aarp_entry to prevent heap info leak aarp_alloc() allocates struct aarp_entry without zeroing it, but only initializes refcnt and packet_queue. When an unresolved AARP entry is created, hwaddr[ETH_ALEN] is left uninitialized. aarp_seq_show() later prints this field with %pM when users read /proc/net/atalk/arp. This can expose 6 bytes of stale heap data for each unresolved entry. Fix this by zero-initializing struct aarp_entry at allocation time. Reported-by: Yizhou Zhao Reported-by: Yuxiang Yang Reported-by: Ao Wang Reported-by: Xuewei Feng Reported-by: Qi Li Reported-by: Ke Xu Signed-off-by: Yizhou Zhao Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260529105017.81531-1-zhaoyz24@mails.tsinghua.edu.cn Signed-off-by: Jakub Kicinski --- net/appletalk/aarp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/appletalk/aarp.c b/net/appletalk/aarp.c index 30493ea3c0107..078fb7a6efa5c 100644 --- a/net/appletalk/aarp.c +++ b/net/appletalk/aarp.c @@ -393,7 +393,7 @@ static void aarp_purge(void) */ static struct aarp_entry *aarp_alloc(void) { - struct aarp_entry *a = kmalloc_obj(*a, GFP_ATOMIC); + struct aarp_entry *a = kzalloc_obj(*a, GFP_ATOMIC); if (!a) return NULL; -- 2.47.3