mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-11-04 02:30:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

sctp: update active_key for asoc when old key is being replaced

Browse source 
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: 1b1e0bc994 ("sctp: add refcnt support for sh_key")
Reported-by: syzbot+b774577370208727d12b@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2021-07-20 16:07:01 -04:00 committed by David S. Miller
parent e9a72f874d
commit 58acd10092
1 changed files with 2 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
net/sctp/auth.c
View file

@ -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);