c6f33e0522
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.