| Message ID | 20201004205536.4734-1-anant.thazhemadam@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | net: team: fix memory leak in __team_options_register | expand |
From: Anant Thazhemadam <anant.thazhemadam@gmail.com> Date: Mon, 5 Oct 2020 02:25:36 +0530 > The variable "i" isn't initialized back correctly after the first loop > under the label inst_rollback gets executed. > > The value of "i" is assigned to be option_count - 1, and the ensuing > loop (under alloc_rollback) begins by initializing i--. > Thus, the value of i when the loop begins execution will now become > i = option_count - 2. > > Thus, when kfree(dst_opts[i]) is called in the second loop in this > order, (i.e., inst_rollback followed by alloc_rollback), > dst_optsp[option_count - 2] is the first element freed, and > dst_opts[option_count - 1] does not get freed, and thus, a memory > leak is caused. > > This memory leak can be fixed, by assigning i = option_count (instead of > option_count - 1). > > Fixes: 80f7c6683fe0 ("team: add support for per-port options") > Reported-by: syzbot+69b804437cfec30deac3@syzkaller.appspotmail.com > Tested-by: syzbot+69b804437cfec30deac3@syzkaller.appspotmail.com > Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com> Applied and queued up for -stable, thank you.
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index 8c1e02752ff6..8986f3ffffe4 100644 --- a/drivers/net/team/team.c +++ b/drivers/net/team/team.c @@ -287,7 +287,7 @@ static int __team_options_register(struct team *team, for (i--; i >= 0; i--) __team_option_inst_del_option(team, dst_opts[i]); - i = option_count - 1; + i = option_count; alloc_rollback: for (i--; i >= 0; i--) kfree(dst_opts[i]);
The variable "i" isn't initialized back correctly after the first loop under the label inst_rollback gets executed. The value of "i" is assigned to be option_count - 1, and the ensuing loop (under alloc_rollback) begins by initializing i--. Thus, the value of i when the loop begins execution will now become i = option_count - 2. Thus, when kfree(dst_opts[i]) is called in the second loop in this order, (i.e., inst_rollback followed by alloc_rollback), dst_optsp[option_count - 2] is the first element freed, and dst_opts[option_count - 1] does not get freed, and thus, a memory leak is caused. This memory leak can be fixed, by assigning i = option_count (instead of option_count - 1). Fixes: 80f7c6683fe0 ("team: add support for per-port options") Reported-by: syzbot+69b804437cfec30deac3@syzkaller.appspotmail.com Tested-by: syzbot+69b804437cfec30deac3@syzkaller.appspotmail.com Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com> --- drivers/net/team/team.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)