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| author | Xin Long <lucien.xin@gmail.com> | 2019-03-03 17:54:55 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-03-08 11:42:49 -0800 |
| commit | c6f33e05225696fee3c901b7526b80f31848454e (patch) | |
| tree | 9a26e6e05b1d2d57672843e37418ff0d17c9fd0d /net/sctp | |
| parent | 60208f79139af0e2f84747d04a2f3321f174a398 (diff) | |
| download | linux-c6f33e05225696fee3c901b7526b80f31848454e.tar.bz2 | |
sctp: call sctp_auth_init_hmacs() in sctp_sock_migrate()
New ep's auth_hmacs should be set if old ep's is set, in case that
net->sctp.auth_enable has been changed to 0 by users and new ep's
auth_hmacs couldn't be set in sctp_endpoint_init().
It can even crash kernel by doing:
1. on server: sysctl -w net.sctp.auth_enable=1,
sysctl -w net.sctp.addip_enable=1,
sysctl -w net.sctp.addip_noauth_enable=0,
listen() on server,
sysctl -w net.sctp.auth_enable=0.
2. on client: connect() to server.
3. on server: accept() the asoc,
sysctl -w net.sctp.auth_enable=1.
4. on client: send() asconf packet to server.
The call trace:
[ 245.280251] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 245.286872] RIP: 0010:sctp_auth_calculate_hmac+0xa3/0x140 [sctp]
[ 245.304572] Call Trace:
[ 245.305091] <IRQ>
[ 245.311287] sctp_sf_authenticate+0x110/0x160 [sctp]
[ 245.312311] sctp_sf_eat_auth+0xf2/0x230 [sctp]
[ 245.313249] sctp_do_sm+0x9a/0x2d0 [sctp]
[ 245.321483] sctp_assoc_bh_rcv+0xed/0x1a0 [sctp]
[ 245.322495] sctp_rcv+0xa66/0xc70 [sctp]
It's because the old ep->auth_hmacs wasn't copied to the new ep while
ep->auth_hmacs is used in sctp_auth_calculate_hmac() when processing
the incoming auth chunks, and it should have been done when migrating
sock.
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/socket.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 44f2acb3d433..6140471efd4b 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -9225,6 +9225,16 @@ static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk, if (err) return err; + /* New ep's auth_hmacs should be set if old ep's is set, in case + * that net->sctp.auth_enable has been changed to 0 by users and + * new ep's auth_hmacs couldn't be set in sctp_endpoint_init(). + */ + if (oldsp->ep->auth_hmacs) { + err = sctp_auth_init_hmacs(newsp->ep, GFP_KERNEL); + if (err) + return err; + } + /* Move any messages in the old socket's receive queue that are for the * peeled off association to the new socket's receive queue. */ |