From: Jouni Malinen Date: Thu, 28 Aug 2008 12:12:06 +0000 (+0300) Subject: mac80211: Fix debugfs union misuse and pointer corruption X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2b58b209399844995ad48e421267e359e16c03db;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git mac80211: Fix debugfs union misuse and pointer corruption debugfs union in struct ieee80211_sub_if_data is misused by including a common default_key dentry as a union member. This ends occupying the same memory area with the first dentry in other union members (structures; usually drop_unencrypted). Consequently, debugfs operations on default_key symlinks and drop_unencrypted entry are using the same dentry pointer even though they are supposed to be separate ones. This can lead to removing entries incorrectly or potentially leaving something behind since one of the dentry pointers gets lost. Fix this by moving the default_key dentry to a new struct (common_debugfs) that contains dentries (more to be added in future) that are shared by all vif types. The debugfs union must only be used for vif type-specific entries to avoid this type of pointer corruption. Signed-off-by: Jouni Malinen Acked-by: Johannes Berg Signed-off-by: John W. Linville --- diff --git a/net/mac80211/debugfs_key.c b/net/mac80211/debugfs_key.c index 7439b63df5d0..cf82acec913a 100644 --- a/net/mac80211/debugfs_key.c +++ b/net/mac80211/debugfs_key.c @@ -265,7 +265,7 @@ void ieee80211_debugfs_key_add_default(struct ieee80211_sub_if_data *sdata) key = sdata->default_key; if (key) { sprintf(buf, "../keys/%d", key->debugfs.cnt); - sdata->debugfs.default_key = + sdata->common_debugfs.default_key = debugfs_create_symlink("default_key", sdata->debugfsdir, buf); } else @@ -277,8 +277,8 @@ void ieee80211_debugfs_key_remove_default(struct ieee80211_sub_if_data *sdata) if (!sdata) return; - debugfs_remove(sdata->debugfs.default_key); - sdata->debugfs.default_key = NULL; + debugfs_remove(sdata->common_debugfs.default_key); + sdata->common_debugfs.default_key = NULL; } void ieee80211_debugfs_key_sta_del(struct ieee80211_key *key, diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 586a9b49b0fc..4498d8713652 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -496,8 +496,10 @@ struct ieee80211_sub_if_data { struct { struct dentry *mode; } monitor; - struct dentry *default_key; } debugfs; + struct { + struct dentry *default_key; + } common_debugfs; #ifdef CONFIG_MAC80211_MESH struct dentry *mesh_stats_dir;