Re: [PATCH 5.10 018/145] net: dcb: Validate netlink message in DCB handler
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-01-11 19:58:59
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On Mon, Jan 11, 2021 at 09:36:16AM -0800, Jakub Kicinski wrote:
On Mon, 11 Jan 2021 14:00:42 +0100 Greg Kroah-Hartman wrote:quoted
From: Petr Machata <redacted> [ 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 <redacted> Link: https://lore.kernel.org/r/a2a9b88418f3a58ef211b718f2970128ef9e3793.1608673640.git.me@pmachata.org (local) Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>Unfortunately we need to call backsies on this one. A fix up was just posted: https://patchwork.kernel.org/project/netdevbpf/patch/a3edcfda0825f2aa2591801c5232f2bbf2d8a554.1610384801.git.me@pmachata.org/ I'll resend both in the next submission.
No worries, thanks for letting me know, I've now dropped it from all stable tree queues. thanks, greg k-h