959dbcf5c3
[ Upstream commit 50c2936634bcb1db78a8ca63249236810c11a80f ]
Digging through the ioctls with Al because of the previous
patches, we found that on 64-bit decnet's dn_dev_ioctl()
is wrong, because struct ifreq::ifr_ifru is actually 24
bytes (not 16 as expected from struct sockaddr) due to the
ifru_map and ifru_settings members.
Clearly, decnet expects the ioctl to be called with a struct
like
struct ifreq_dn {
char ifr_name[IFNAMSIZ];
struct sockaddr_dn ifr_addr;
};
since it does
struct ifreq *ifr = ...;
struct sockaddr_dn *sdn = (struct sockaddr_dn *)&ifr->ifr_addr;
This means that DN_IFREQ_SIZE is too big for what it wants on
64-bit, as it is
sizeof(struct ifreq) - sizeof(struct sockaddr) +
sizeof(struct sockaddr_dn)
This assumes that sizeof(struct sockaddr) is the size of ifr_ifru
but that isn't true.
Fix this to use offsetof(struct ifreq, ifr_ifru).
This indeed doesn't really matter much - the result is that we
copy in/out 8 bytes more than we should on 64-bit platforms. In
case the "struct ifreq_dn" lands just on the end of a page though
it might lead to faults.
As far as I can tell, it has been like this forever, so it seems
very likely that nobody cares.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
||
|---|---|---|
| .. | ||
| netfilter | ||
| af_decnet.c | ||
| dn_dev.c | ||
| dn_fib.c | ||
| dn_neigh.c | ||
| dn_nsp_in.c | ||
| dn_nsp_out.c | ||
| dn_route.c | ||
| dn_rules.c | ||
| dn_table.c | ||
| dn_timer.c | ||
| Kconfig | ||
| Makefile | ||
| README | ||
| sysctl_net_decnet.c | ||
| TODO | ||
Linux DECnet Project
======================
The documentation for this kernel subsystem is available in the
Documentation/networking subdirectory of this distribution and also
on line at http://www.chygwyn.com/DECnet/
Steve Whitehouse <SteveW@ACM.org>