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| author | Petr Machata <me@pmachata.org> | 2020-12-23 00:49:44 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-23 18:04:01 +0300 |
| commit | dbdca9d9b7ca909744928450edf563452301e65a (patch) | |
| tree | f23cd69017414de147baadd673416e7ad59b4eea | |
| parent | 26413630f4f6495dc28ad57e6031f55912d1bcc7 (diff) | |
| download | linux-dbdca9d9b7ca909744928450edf563452301e65a.tar.xz | |
net: dcb: Validate netlink message in DCB handler
[ Upstream commit 826f328e2b7e8854dd42ea44e6519cd75018e7b1 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 16014ad19406..098356406494 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; |