From: Amol Grover frextrite@gmail.com
[ Upstream commit bc62d68e2a0a69fcdcf28aca8edb01abf306b698 ]
exceptions may be traversed using list_for_each_entry_rcu() outside of an RCU read side critical section BUT under the protection of decgroup_mutex. Hence add the corresponding lockdep expression to fix the following false-positive warning:
[ 2.304417] ============================= [ 2.304418] WARNING: suspicious RCU usage [ 2.304420] 5.5.4-stable #17 Tainted: G E [ 2.304422] ----------------------------- [ 2.304424] security/device_cgroup.c:355 RCU-list traversed in non-reader section!!
Signed-off-by: Amol Grover frextrite@gmail.com Signed-off-by: James Morris jmorris@namei.org Signed-off-by: Sasha Levin sashal@kernel.org --- security/device_cgroup.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 725674f3276d3..5d7bb91c64876 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -352,7 +352,8 @@ static bool match_exception_partial(struct list_head *exceptions, short type, { struct dev_exception_item *ex;
- list_for_each_entry_rcu(ex, exceptions, list) { + list_for_each_entry_rcu(ex, exceptions, list, + lockdep_is_held(&devcgroup_mutex)) { if ((type & DEVCG_DEV_BLOCK) && !(ex->type & DEVCG_DEV_BLOCK)) continue; if ((type & DEVCG_DEV_CHAR) && !(ex->type & DEVCG_DEV_CHAR))