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authorEric Dumazet <eric.dumazet@gmail.com>2009-11-06 00:23:01 +0000
committerDavid S. Miller <davem@davemloft.net>2009-11-08 00:33:43 -0800
commit6755aebaaf9fc5416acfd4578ab7a1e122ecbc74 (patch)
tree09f23419b097b15e7c36954cb98bdf28cdfa5af1 /net/can
parentcc05368c52fed7d9efa0f56c5270e95bb569713e (diff)
downloadlinux-2.6.38-lt-ux500-6755aebaaf9fc5416acfd4578ab7a1e122ecbc74.tar.gz
can: should not use __dev_get_by_index() without locks
bcm_proc_getifname() is called with RTNL and dev_base_lock not held. It calls __dev_get_by_index() without locks, and this is illegal (might crash) Close the race by holding dev_base_lock and copying dev->name in the protected section. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/bcm.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 597da4f8f88..e8d58f33fe0 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -132,23 +132,27 @@ static inline struct bcm_sock *bcm_sk(const struct sock *sk)
/*
* procfs functions
*/
-static char *bcm_proc_getifname(int ifindex)
+static char *bcm_proc_getifname(char *result, int ifindex)
{
struct net_device *dev;
if (!ifindex)
return "any";
- /* no usage counting */
+ read_lock(&dev_base_lock);
dev = __dev_get_by_index(&init_net, ifindex);
if (dev)
- return dev->name;
+ strcpy(result, dev->name);
+ else
+ strcpy(result, "???");
+ read_unlock(&dev_base_lock);
- return "???";
+ return result;
}
static int bcm_proc_show(struct seq_file *m, void *v)
{
+ char ifname[IFNAMSIZ];
struct sock *sk = (struct sock *)m->private;
struct bcm_sock *bo = bcm_sk(sk);
struct bcm_op *op;
@@ -157,7 +161,7 @@ static int bcm_proc_show(struct seq_file *m, void *v)
seq_printf(m, " / sk %p", sk);
seq_printf(m, " / bo %p", bo);
seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
- seq_printf(m, " / bound %s", bcm_proc_getifname(bo->ifindex));
+ seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
seq_printf(m, " <<<\n");
list_for_each_entry(op, &bo->rx_ops, list) {
@@ -169,7 +173,7 @@ static int bcm_proc_show(struct seq_file *m, void *v)
continue;
seq_printf(m, "rx_op: %03X %-5s ",
- op->can_id, bcm_proc_getifname(op->ifindex));
+ op->can_id, bcm_proc_getifname(ifname, op->ifindex));
seq_printf(m, "[%d]%c ", op->nframes,
(op->flags & RX_CHECK_DLC)?'d':' ');
if (op->kt_ival1.tv64)
@@ -194,7 +198,8 @@ static int bcm_proc_show(struct seq_file *m, void *v)
list_for_each_entry(op, &bo->tx_ops, list) {
seq_printf(m, "tx_op: %03X %s [%d] ",
- op->can_id, bcm_proc_getifname(op->ifindex),
+ op->can_id,
+ bcm_proc_getifname(ifname, op->ifindex),
op->nframes);
if (op->kt_ival1.tv64)