linux/net/sctp
Daniel Borkmann 4184b2a79a net: sctp: fix memory leak in auth key management
A very minimal and simple user space application allocating an SCTP
socket, setting SCTP_AUTH_KEY setsockopt(2) on it and then closing
the socket again will leak the memory containing the authentication
key from user space:

unreferenced object 0xffff8800837047c0 (size 16):
  comm "a.out", pid 2789, jiffies 4296954322 (age 192.258s)
  hex dump (first 16 bytes):
    01 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff816d7e8e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811c88d8>] __kmalloc+0xe8/0x270
    [<ffffffffa0870c23>] sctp_auth_create_key+0x23/0x50 [sctp]
    [<ffffffffa08718b1>] sctp_auth_set_key+0xa1/0x140 [sctp]
    [<ffffffffa086b383>] sctp_setsockopt+0xd03/0x1180 [sctp]
    [<ffffffff815bfd94>] sock_common_setsockopt+0x14/0x20
    [<ffffffff815beb61>] SyS_setsockopt+0x71/0xd0
    [<ffffffff816e58a9>] system_call_fastpath+0x12/0x17
    [<ffffffffffffffff>] 0xffffffffffffffff

This is bad because of two things, we can bring down a machine from
user space when auth_enable=1, but also we would leave security sensitive
keying material in memory without clearing it after use. The issue is
that sctp_auth_create_key() already sets the refcount to 1, but after
allocation sctp_auth_set_key() does an additional refcount on it, and
thus leaving it around when we free the socket.

Fixes: 65b07e5d0d ("[SCTP]: API updates to suport SCTP-AUTH extensions.")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-11 15:19:11 -05:00
..
associola.c net: sctp: fix panic on duplicate ASCONF chunks 2014-10-14 12:46:22 -04:00
auth.c net: sctp: fix memory leak in auth key management 2014-11-11 15:19:11 -05:00
bind_addr.c
chunk.c
debug.c
endpointola.c
input.c sctp: Change sctp to implement csum_levels 2014-08-29 20:41:11 -07:00
inqueue.c net: sctp: fix remote memory pressure from excessive queueing 2014-10-14 12:46:22 -04:00
ipv6.c sctp: Fixup v4mapped behaviour to comply with Sock API 2014-07-31 21:49:06 -07:00
Kconfig
Makefile net: sctp: Inline the functions from command.c 2014-07-08 14:38:48 -07:00
objcnt.c
output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-08-05 18:46:26 -07:00
outqueue.c net: sctp: Rename SCTP_XMIT_NAGLE_DELAY to SCTP_XMIT_DELAY 2014-07-22 13:32:11 -07:00
primitive.c
probe.c
proc.c
protocol.c Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-10 07:26:02 -04:00
sm_make_chunk.c net: sctp: fix NULL pointer dereference in af->from_addr_param on malformed packet 2014-11-11 15:19:10 -05:00
sm_sideeffect.c
sm_statefuns.c net: sctp: fix remote memory pressure from excessive queueing 2014-10-14 12:46:22 -04:00
sm_statetable.c
socket.c net: sctp: fix ABI mismatch through sctp_assoc_to_state helper 2014-08-29 20:31:08 -07:00
ssnmap.c
sysctl.c net: sctp: only warn in proc_sctp_do_alpha_beta if write 2014-07-02 18:44:07 -07:00
transport.c sctp: Fixup v4mapped behaviour to comply with Sock API 2014-07-31 21:49:06 -07:00
tsnmap.c
ulpevent.c sctp: Fixup v4mapped behaviour to comply with Sock API 2014-07-31 21:49:06 -07:00
ulpqueue.c