From f87e6f47933e3ebeced9bb12615e830a72cedce4 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 17 Feb 2011 22:54:38 +0000 Subject: net: dont leave active on stack LIST_HEAD Eric W. Biderman and Michal Hocko reported various memory corruptions that we suspected to be related to a LIST head located on stack, that was manipulated after thread left function frame (and eventually exited, so its stack was freed and reused). Eric Dumazet suggested the problem was probably coming from commit 443457242beb (net: factorize sync-rcu call in unregister_netdevice_many) This patch fixes __dev_close() and dev_close() to properly deinit their respective LIST_HEAD(single) before exiting. References: https://lkml.org/lkml/2011/2/16/304 References: https://lkml.org/lkml/2011/2/14/223 Reported-by: Michal Hocko Tested-by: Michal Hocko Reported-by: Eric W. Biderman Tested-by: Eric W. Biderman Signed-off-by: Linus Torvalds Signed-off-by: Eric Dumazet CC: Ingo Molnar CC: Octavian Purdila Signed-off-by: David S. Miller --- net/core/dev.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 8e726cb47ed..a18c1643ea9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1280,10 +1280,13 @@ static int __dev_close_many(struct list_head *head) static int __dev_close(struct net_device *dev) { + int retval; LIST_HEAD(single); list_add(&dev->unreg_list, &single); - return __dev_close_many(&single); + retval = __dev_close_many(&single); + list_del(&single); + return retval; } int dev_close_many(struct list_head *head) @@ -1325,7 +1328,7 @@ int dev_close(struct net_device *dev) list_add(&dev->unreg_list, &single); dev_close_many(&single); - + list_del(&single); return 0; } EXPORT_SYMBOL(dev_close); -- cgit v1.2.3-18-g5258 From ceaaec98ad99859ac90ac6863ad0a6cd075d8e0e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 17 Feb 2011 22:59:19 +0000 Subject: net: deinit automatic LIST_HEAD commit 9b5e383c11b08784 (net: Introduce unregister_netdevice_many()) left an active LIST_HEAD() in rollback_registered(), with possible memory corruption. Even if device is freed without touching its unreg_list (and therefore touching the previous memory location holding LISTE_HEAD(single), better close the bug for good, since its really subtle. (Same fix for default_device_exit_batch() for completeness) Reported-by: Michal Hocko Tested-by: Michal Hocko Reported-by: Eric W. Biderman Tested-by: Eric W. Biderman Signed-off-by: Linus Torvalds Signed-off-by: Eric Dumazet CC: Ingo Molnar CC: Octavian Purdila CC: stable [.33+] Signed-off-by: David S. Miller --- net/core/dev.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index a18c1643ea9..8ae6631abcc 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5066,6 +5066,7 @@ static void rollback_registered(struct net_device *dev) list_add(&dev->unreg_list, &single); rollback_registered_many(&single); + list_del(&single); } unsigned long netdev_fix_features(unsigned long features, const char *name) @@ -6219,6 +6220,7 @@ static void __net_exit default_device_exit_batch(struct list_head *net_list) } } unregister_netdevice_many(&dev_kill_list); + list_del(&dev_kill_list); rtnl_unlock(); } -- cgit v1.2.3-18-g5258