From 36fd71d293898a59b14e49da1f6e81c1a58f2035 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 2 Sep 2008 14:35:52 -0700 Subject: devcgroup: fix race against rmdir() During the use of a dev_cgroup, we should guarantee the corresponding cgroup won't be deleted (i.e. via rmdir). This can be done through css_get(&dev_cgroup->css), but here we can just get and use the dev_cgroup under rcu_read_lock. And also remove checking NULL dev_cgroup, it won't be NULL since a task always belongs to a cgroup. Signed-off-by: Li Zefan Acked-by: Serge Hallyn Cc: Paul Menage Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/device_cgroup.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'security') diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 7bd296cca04..46f23971f7e 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -508,12 +508,11 @@ int devcgroup_inode_permission(struct inode *inode, int mask) return 0; if (!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode)) return 0; - dev_cgroup = css_to_devcgroup(task_subsys_state(current, - devices_subsys_id)); - if (!dev_cgroup) - return 0; rcu_read_lock(); + + dev_cgroup = task_devcgroup(current); + list_for_each_entry_rcu(wh, &dev_cgroup->whitelist, list) { if (wh->type & DEV_ALL) goto acc_check; @@ -533,6 +532,7 @@ acc_check: rcu_read_unlock(); return 0; } + rcu_read_unlock(); return -EPERM; @@ -543,12 +543,10 @@ int devcgroup_inode_mknod(int mode, dev_t dev) struct dev_cgroup *dev_cgroup; struct dev_whitelist_item *wh; - dev_cgroup = css_to_devcgroup(task_subsys_state(current, - devices_subsys_id)); - if (!dev_cgroup) - return 0; - rcu_read_lock(); + + dev_cgroup = task_devcgroup(current); + list_for_each_entry(wh, &dev_cgroup->whitelist, list) { if (wh->type & DEV_ALL) goto acc_check; @@ -566,6 +564,8 @@ acc_check: rcu_read_unlock(); return 0; } + rcu_read_unlock(); + return -EPERM; } -- cgit v1.2.3 From 8e531af90f3940615623dc0aa6c94866a6773601 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 3 Sep 2008 11:49:47 -0400 Subject: SELinux: memory leak in security_context_to_sid_core Fix a bug and a philosophical decision about who handles errors. security_context_to_sid_core() was leaking a context in the common case. This was causing problems on fedora systems which recently have started making extensive use of this function. In discussion it was decided that if string_to_context_struct() had an error it was its own responsibility to clean up any mess it created along the way. Signed-off-by: Eric Paris Acked-by: Stephen Smalley Signed-off-by: James Morris --- security/selinux/ss/services.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'security') diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index b52f923ce68..d11a8154500 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -811,11 +811,12 @@ static int string_to_context_struct(struct policydb *pol, /* Check the validity of the new context. */ if (!policydb_context_isvalid(pol, ctx)) { rc = -EINVAL; - context_destroy(ctx); goto out; } rc = 0; out: + if (rc) + context_destroy(ctx); return rc; } @@ -868,8 +869,7 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len, } else if (rc) goto out; rc = sidtab_context_to_sid(&sidtab, &context, sid); - if (rc) - context_destroy(&context); + context_destroy(&context); out: read_unlock(&policy_rwlock); kfree(scontext2); -- cgit v1.2.3