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| author | Daniel Borkmann <dborkman@redhat.com> | 2014-11-10 18:00:09 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-11-11 15:19:11 -0500 |
| commit | 4184b2a79a7612a9272ce20d639934584a1f3786 (patch) | |
| tree | 9250d77d2d898115bd071a25071941ff37e4b270 /net/sctp | |
| parent | e40607cbe270a9e8360907cb1e62ddf0736e4864 (diff) | |
| download | lwn-4184b2a79a7612a9272ce20d639934584a1f3786.tar.gz lwn-4184b2a79a7612a9272ce20d639934584a1f3786.zip | |
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: 65b07e5d0d0 ("[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>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/auth.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/sctp/auth.c b/net/sctp/auth.c index 0e8529113dc5..fb7976aee61c 100644 --- a/net/sctp/auth.c +++ b/net/sctp/auth.c @@ -862,8 +862,6 @@ int sctp_auth_set_key(struct sctp_endpoint *ep, list_add(&cur_key->key_list, sh_keys); cur_key->key = key; - sctp_auth_key_hold(key); - return 0; nomem: if (!replace) |