From aaa53c4aba14f14de06419a20e552fe2d8823a33 Mon Sep 17 00:00:00 2001 From: Benjamin Thery Date: Fri, 24 Aug 2007 23:12:08 -0700 Subject: [NET]: Fix crash in dev_mc_sync()/dev_mc_unsync() This patch fixes a crash that may occur when the routine dev_mc_sync() deletes an address from the list it is currently going through. It saves the pointer to the next element before deleting the current one. The problem may also exist in dev_mc_unsync(). Signed-off-by: Benjamin Thery Acked-by: Patrick McHardy Signed-off-by: David S. Miller --- net/core/dev_mcast.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'net/core') diff --git a/net/core/dev_mcast.c b/net/core/dev_mcast.c index 99aece1aecc..20330c57261 100644 --- a/net/core/dev_mcast.c +++ b/net/core/dev_mcast.c @@ -116,11 +116,13 @@ int dev_mc_add(struct net_device *dev, void *addr, int alen, int glbl) */ int dev_mc_sync(struct net_device *to, struct net_device *from) { - struct dev_addr_list *da; + struct dev_addr_list *da, *next; int err = 0; netif_tx_lock_bh(to); - for (da = from->mc_list; da != NULL; da = da->next) { + da = from->mc_list; + while (da != NULL) { + next = da->next; if (!da->da_synced) { err = __dev_addr_add(&to->mc_list, &to->mc_count, da->da_addr, da->da_addrlen, 0); @@ -134,6 +136,7 @@ int dev_mc_sync(struct net_device *to, struct net_device *from) __dev_addr_delete(&from->mc_list, &from->mc_count, da->da_addr, da->da_addrlen, 0); } + da = next; } if (!err) __dev_set_rx_mode(to); @@ -156,12 +159,14 @@ EXPORT_SYMBOL(dev_mc_sync); */ void dev_mc_unsync(struct net_device *to, struct net_device *from) { - struct dev_addr_list *da; + struct dev_addr_list *da, *next; netif_tx_lock_bh(from); netif_tx_lock_bh(to); - for (da = from->mc_list; da != NULL; da = da->next) { + da = from->mc_list; + while (da != NULL) { + next = da->next; if (!da->da_synced) continue; __dev_addr_delete(&to->mc_list, &to->mc_count, @@ -169,6 +174,7 @@ void dev_mc_unsync(struct net_device *to, struct net_device *from) da->da_synced = 0; __dev_addr_delete(&from->mc_list, &from->mc_count, da->da_addr, da->da_addrlen, 0); + da = next; } __dev_set_rx_mode(to); -- cgit v1.2.3