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| author | Dmitry Safonov <dima@arista.com> | 2020-11-02 16:14:45 +0000 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2020-11-09 07:34:56 +0100 |
| commit | dbd7ae5154d5fff7e84a9f3010bb06499017ef29 (patch) | |
| tree | 35183e43eb4bd53618964f00349bf74134ee9f87 /net/xfrm | |
| parent | 4e0396c59559264442963b349ab71f66e471f84d (diff) | |
| download | linux-dbd7ae5154d5fff7e84a9f3010bb06499017ef29.tar.bz2 | |
xfrm/compat: Translate by copying XFRMA_UNSPEC attribute
xfrm_xlate32() translates 64-bit message provided by kernel to be sent
for 32-bit listener (acknowledge or monitor). Translator code doesn't
expect XFRMA_UNSPEC attribute as it doesn't know its payload.
Kernel never attaches such attribute, but a user can.
I've searched if any opensource does it and the answer is no.
Nothing on github and google finds only tfcproject that has such code
commented-out.
What will happen if a user sends a netlink message with XFRMA_UNSPEC
attribute? Ipsec code ignores this attribute. But if there is a
monitor-process or 32-bit user requested ack - kernel will try to
translate such message and will hit WARN_ONCE() in xfrm_xlate64_attr().
Deal with XFRMA_UNSPEC by copying the attribute payload with
xfrm_nla_cpy(). In result, the default switch-case in xfrm_xlate64_attr()
becomes an unused code. Leave those 3 lines in case a new xfrm attribute
will be added.
Fixes: 5461fc0c8d9f ("xfrm/compat: Add 64=>32-bit messages translator")
Reported-by: syzbot+a7e701c8385bd8543074@syzkaller.appspotmail.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm')
| -rw-r--r-- | net/xfrm/xfrm_compat.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c index e28f0c9ecd6a..17edbf935e35 100644 --- a/net/xfrm/xfrm_compat.c +++ b/net/xfrm/xfrm_compat.c @@ -234,6 +234,7 @@ static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src) case XFRMA_PAD: /* Ignore */ return 0; + case XFRMA_UNSPEC: case XFRMA_ALG_AUTH: case XFRMA_ALG_CRYPT: case XFRMA_ALG_COMP: |