diff options
| author | Petr Machata <me@pmachata.org> | 2020-12-23 00:49:44 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-12-23 23:19:48 +0300 |
| commit | 826f328e2b7e8854dd42ea44e6519cd75018e7b1 (patch) | |
| tree | f0b822b652a6db49ed1f3ea675364771f1b722c1 | |
| parent | 6313138619f398666212577f8b4f0ddf215a2bed (diff) | |
| download | linux-826f328e2b7e8854dd42ea44e6519cd75018e7b1.tar.xz | |
net: dcb: Validate netlink message in DCB handler
DCB uses the same handler function for both RTM_GETDCB and RTM_SETDCB
messages. dcb_doit() bounces RTM_SETDCB mesasges if the user does not have
the CAP_NET_ADMIN capability.
However, the operation to be performed is not decided from the DCB message
type, but from the DCB command. Thus DCB_CMD_*_GET commands are used for
reading DCB objects, the corresponding SET and DEL commands are used for
manipulation.
The assumption is that set-like commands will be sent via an RTM_SETDCB
message, and get-like ones via RTM_GETDCB. However, this assumption is not
enforced.
It is therefore possible to manipulate DCB objects without CAP_NET_ADMIN
capability by sending the corresponding command in an RTM_GETDCB message.
That is a bug. Fix it by validating the type of the request message against
the type used for the response.
Fixes: 2f90b8657ec9 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver")
Signed-off-by: Petr Machata <me@pmachata.org>
Link: https://lore.kernel.org/r/a2a9b88418f3a58ef211b718f2970128ef9e3793.1608673640.git.me@pmachata.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/dcb/dcbnl.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c index 084e159a12ba..7d49b6fd6cef 100644 --- a/net/dcb/dcbnl.c +++ b/net/dcb/dcbnl.c @@ -1765,6 +1765,8 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh, fn = &reply_funcs[dcb->cmd]; if (!fn->cb) return -EOPNOTSUPP; + if (fn->type != nlh->nlmsg_type) + return -EPERM; if (!tb[DCB_ATTR_IFNAME]) return -EINVAL; |