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| author | Xin Long <lucien.xin@gmail.com> | 2021-07-20 16:07:01 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-07-21 08:44:44 -0700 |
| commit | 58acd10092268831e49de279446c314727101292 (patch) | |
| tree | 197be27e40b6320e256a463deb069a4c1681ce41 /net/sctp/auth.c | |
| parent | e9a72f874d5b95cef0765bafc56005a50f72c5fe (diff) | |
| download | lwn-58acd10092268831e49de279446c314727101292.tar.gz lwn-58acd10092268831e49de279446c314727101292.zip | |
sctp: update active_key for asoc when old key is being replaced
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp/auth.c')
| -rw-r--r-- | net/sctp/auth.c | 2 |
1 files changed, 2 insertions, 0 deletions
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); |