From 5ffda6998be51a8abb11b911087ebdd83ddfe7c5 Mon Sep 17 00:00:00 2001 From: Florent Revest Date: Wed, 6 Dec 2023 13:37:18 +0100 Subject: [PATCH] team: Fix use-after-free when an option instance allocation fails commit c12296bbecc488623b7d1932080e394d08f3226b upstream. In __team_options_register, team_options are allocated and appended to the team's option_list. If one option instance allocation fails, the "inst_rollback" cleanup path frees the previously allocated options but doesn't remove them from the team's option_list. This leaves dangling pointers that can be dereferenced later by other parts of the team driver that iterate over options. This patch fixes the cleanup path to remove the dangling pointers from the list. As far as I can tell, this uaf doesn't have much security implications since it would be fairly hard to exploit (an attacker would need to make the allocation of that specific small object fail) but it's still nice to fix. Cc: stable@vger.kernel.org Fixes: 80f7c6683fe0 ("team: add support for per-port options") Signed-off-by: Florent Revest Reviewed-by: Jiri Pirko Reviewed-by: Hangbin Liu Link: https://lore.kernel.org/r/20231206123719.1963153-1-revest@chromium.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/team/team.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index 97a77dabed64..49d7030ddc1b 100644 --- a/drivers/net/team/team.c +++ b/drivers/net/team/team.c @@ -284,8 +284,10 @@ static int __team_options_register(struct team *team, return 0; inst_rollback: - for (i--; i >= 0; i--) + for (i--; i >= 0; i--) { __team_option_inst_del_option(team, dst_opts[i]); + list_del(&dst_opts[i]->list); + } i = option_count; alloc_rollback: