From: Joao Moreira <joao.moreira@xxxxxxxxx> Both flow_rule_alloc and offload_action_alloc functions received an unsigned num_actions parameters which are then operated within a loop. The index of this loop is declared as a signed int. If it was possible to pass a large enough num_actions to these functions, it would lead to an out of bounds write. After checking with maintainers, it was mentioned that front-end will cap the num_actions value and that it is not possible to reach this function with such a large number. Yet, for correctness, it is still better to fix this. This issue was observed by the commit author while reviewing a write-up regarding a CVE within the same subsystem [1]. 1 - https://nickgregory.me/post/2022/03/12/cve-2022-25636/ Signed-off-by: Joao Moreira <joao.moreira@xxxxxxxxx> --- net/core/flow_offload.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/flow_offload.c b/net/core/flow_offload.c index bc5169482710..bc3f53a09d8f 100644 --- a/net/core/flow_offload.c +++ b/net/core/flow_offload.c @@ -10,7 +10,7 @@ struct flow_rule *flow_rule_alloc(unsigned int num_actions) { struct flow_rule *rule; - int i; + unsigned int i; rule = kzalloc(struct_size(rule, action.entries, num_actions), GFP_KERNEL); @@ -31,7 +31,7 @@ EXPORT_SYMBOL(flow_rule_alloc); struct flow_offload_action *offload_action_alloc(unsigned int num_actions) { struct flow_offload_action *fl_action; - int i; + unsigned int i; fl_action = kzalloc(struct_size(fl_action, action.entries, num_actions), GFP_KERNEL); -- 2.42.0
