Thread (5 messages) 5 messages, 4 authors, 2018-03-08

Re: [PATCH] net: don't unnecessarily load kernel modules in dev_ioctl()

From: Stephen Hemminger <hidden>
Date: 2018-03-06 23:59:20
Also in: linux-security-module, selinux

On Tue, 06 Mar 2018 17:27:44 -0500
Paul Moore [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Paul Moore <redacted>

Starting with v4.16-rc1 we've been seeing a higher than usual number
of requests for the kernel to load networking modules, even on events
which shouldn't trigger a module load (e.g. ioctl(TCGETS)).  Stephen
Smalley suggested the problem may lie in commit 44c02a2c3dc5
("dev_ioctl(): move copyin/copyout to callers") which moves changes
the network dev_ioctl() function to always call dev_load(),
regardless of the requested ioctl.

This patch moves the dev_load() calls back into the individual ioctls
while preserving the rest of the original patch.

Reported-by: Dominick Grift <redacted>
Suggested-by: Stephen Smalley <redacted>
Signed-off-by: Paul Moore <redacted>
---
 net/core/dev_ioctl.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index 0ab1af04296c..a04e1e88bf3a 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -402,8 +402,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, bool *need_c
 	if (colon)
 		*colon = 0;
 
-	dev_load(net, ifr->ifr_name);
Actually dev_load by ethernet name is really a legacy thing that should just die,

It was kept around so that some very tunnel configuration using special names.

	# ifconfig sit0

which probably several web pages still tell users to do...
We have much better control now with ip commands so that this is just
baggage.
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