NETROM: Fix use of static buffer
From: Ralf Baechle <hidden>
Date: 2009-08-17 16:16:36
Also in:
linux-hams
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The static variable used by nr_call_to_digi might result in corruption if multiple threads are trying to usee a node or neighbour via ioctl. Fixed by having the caller pass a structure in. This is safe because nr_add_node rsp. nr_add_neigh will allocate a permanent structure, if needed. Signed-off-by: Ralf Baechle <redacted> net/netrom/nr_route.c | 21 ++++++++++++--------- 1 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index e943c16..4eb1ac9 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c@@ -630,23 +630,23 @@ out: return dev; } -static ax25_digi *nr_call_to_digi(int ndigis, ax25_address *digipeaters) +static ax25_digi *nr_call_to_digi(ax25_digi *digi, int ndigis, + ax25_address *digipeaters) { - static ax25_digi ax25_digi; int i; if (ndigis == 0) return NULL; for (i = 0; i < ndigis; i++) { - ax25_digi.calls[i] = digipeaters[i]; - ax25_digi.repeated[i] = 0; + digi->calls[i] = digipeaters[i]; + digi->repeated[i] = 0; } - ax25_digi.ndigi = ndigis; - ax25_digi.lastrepeat = -1; + digi->ndigi = ndigis; + digi->lastrepeat = -1; - return &ax25_digi; + return digi; } /*
@@ -656,6 +656,7 @@ int nr_rt_ioctl(unsigned int cmd, void __user *arg) { struct nr_route_struct nr_route; struct net_device *dev; + ax25_digi digi; int ret; switch (cmd) {
@@ -673,13 +674,15 @@ int nr_rt_ioctl(unsigned int cmd, void __user *arg) ret = nr_add_node(&nr_route.callsign, nr_route.mnemonic, &nr_route.neighbour, - nr_call_to_digi(nr_route.ndigis, nr_route.digipeaters), + nr_call_to_digi(&digi, nr_route.ndigis, + nr_route.digipeaters), dev, nr_route.quality, nr_route.obs_count); break; case NETROM_NEIGH: ret = nr_add_neigh(&nr_route.callsign, - nr_call_to_digi(nr_route.ndigis, nr_route.digipeaters), + nr_call_to_digi(&digi, nr_route.ndigis, + nr_route.digipeaters), dev, nr_route.quality); break; default: