| Message ID | a1e260329384a040f11f0f393327e25cf909da2e.1626811621.git.lucien.xin@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [net] sctp: update active_key for asoc when old key is being replaced | expand |
Hello: This patch was applied to netdev/net.git (refs/heads/master): On Tue, 20 Jul 2021 16:07:01 -0400 you wrote: > syzbot reported a call trace: > > BUG: KASAN: use-after-free in sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 > Call Trace: > sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 > sctp_set_owner_w net/sctp/socket.c:131 [inline] > sctp_sendmsg_to_asoc+0x152e/0x2180 net/sctp/socket.c:1865 > sctp_sendmsg+0x103b/0x1d30 net/sctp/socket.c:2027 > inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 > sock_sendmsg_nosec net/socket.c:703 [inline] > sock_sendmsg+0xcf/0x120 net/socket.c:723 > > [...] Here is the summary with links: - [net] sctp: update active_key for asoc when old key is being replaced https://git.kernel.org/netdev/net/c/58acd1009226 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/net/sctp/auth.c b/net/sctp/auth.c index 6f8319b828b0..fe74c5f95630 100644 --- a/net/sctp/auth.c +++ b/net/sctp/auth.c @@ -860,6 +860,8 @@ int sctp_auth_set_key(struct sctp_endpoint *ep, if (replace) { list_del_init(&shkey->key_list); sctp_auth_shkey_release(shkey); + if (asoc && asoc->active_key_id == auth_key->sca_keynumber) + sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL); } list_add(&cur_key->key_list, sh_keys);
syzbot reported a call trace: BUG: KASAN: use-after-free in sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 Call Trace: sctp_auth_shkey_hold+0x22/0xa0 net/sctp/auth.c:112 sctp_set_owner_w net/sctp/socket.c:131 [inline] sctp_sendmsg_to_asoc+0x152e/0x2180 net/sctp/socket.c:1865 sctp_sendmsg+0x103b/0x1d30 net/sctp/socket.c:2027 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 This is an use-after-free issue caused by not updating asoc->shkey after it was replaced in the key list asoc->endpoint_shared_keys, and the old key was freed. This patch is to fix by also updating active_key for asoc when old key is being replaced with a new one. Note that this issue doesn't exist in sctp_auth_del_key_id(), as it's not allowed to delete the active_key from the asoc. Fixes: 1b1e0bc99474 ("sctp: add refcnt support for sh_key") Reported-by: syzbot+b774577370208727d12b@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> --- net/sctp/auth.c | 2 ++ 1 file changed, 2 insertions(+)