diff mbox series

ax25: fix reference count leaks of ax25_dev

Message ID 20220203150811.42256-1-duoming@zju.edu.cn (mailing list archive)
State Accepted
Commit 87563a043cef044fed5db7967a75741cc16ad2b1
Delegated to: Netdev Maintainers
Headers show
Series ax25: fix reference count leaks of ax25_dev | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Duoming Zhou Feb. 3, 2022, 3:08 p.m. UTC 
The previous commit d01ffb9eee4a ("ax25: add refcount in ax25_dev
to avoid UAF bugs") introduces refcount into ax25_dev, but there
are reference leak paths in ax25_ctl_ioctl(), ax25_fwd_ioctl(),
ax25_rt_add(), ax25_rt_del() and ax25_rt_opt().

This patch uses ax25_dev_put() and adjusts the position of
ax25_addr_ax25dev() to fix reference cout leaks of ax25_dev.

Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
---
 include/net/ax25.h    |  8 +++++---
 net/ax25/af_ax25.c    | 12 ++++++++----
 net/ax25/ax25_dev.c   | 24 +++++++++++++++++-------
 net/ax25/ax25_route.c | 16 +++++++++++-----
 4 files changed, 41 insertions(+), 19 deletions(-)

Comments

Dan Carpenter Feb. 3, 2022, 5:14 p.m. UTC | #1 
On Thu, Feb 03, 2022 at 11:08:11PM +0800, Duoming Zhou wrote:
> The previous commit d01ffb9eee4a ("ax25: add refcount in ax25_dev
> to avoid UAF bugs") introduces refcount into ax25_dev, but there
> are reference leak paths in ax25_ctl_ioctl(), ax25_fwd_ioctl(),
> ax25_rt_add(), ax25_rt_del() and ax25_rt_opt().
> 
> This patch uses ax25_dev_put() and adjusts the position of
> ax25_addr_ax25dev() to fix reference cout leaks of ax25_dev.
> 
> Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs")
> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
> ---

Much better, thanks!

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter
patchwork-bot+netdevbpf@kernel.org Feb. 3, 2022, 11 p.m. UTC | #2 
Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu,  3 Feb 2022 23:08:11 +0800 you wrote:
> The previous commit d01ffb9eee4a ("ax25: add refcount in ax25_dev
> to avoid UAF bugs") introduces refcount into ax25_dev, but there
> are reference leak paths in ax25_ctl_ioctl(), ax25_fwd_ioctl(),
> ax25_rt_add(), ax25_rt_del() and ax25_rt_opt().
> 
> This patch uses ax25_dev_put() and adjusts the position of
> ax25_addr_ax25dev() to fix reference cout leaks of ax25_dev.
> 
> [...]

Here is the summary with links:
  - ax25: fix reference count leaks of ax25_dev
    https://git.kernel.org/netdev/net/c/87563a043cef

You are awesome, thank you!
diff mbox series

Patch

diff --git a/include/net/ax25.h b/include/net/ax25.h
index 50b417df622..8221af1811d 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -294,10 +294,12 @@  static __inline__ void ax25_cb_put(ax25_cb *ax25)
 	}
 }
 
-#define ax25_dev_hold(__ax25_dev) \
-	refcount_inc(&((__ax25_dev)->refcount))
+static inline void ax25_dev_hold(ax25_dev *ax25_dev)
+{
+	refcount_inc(&ax25_dev->refcount);
+}
 
-static __inline__ void ax25_dev_put(ax25_dev *ax25_dev)
+static inline void ax25_dev_put(ax25_dev *ax25_dev)
 {
 	if (refcount_dec_and_test(&ax25_dev->refcount)) {
 		kfree(ax25_dev);
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 32f61978ff2..3e49d28824e 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -359,21 +359,25 @@  static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg)
 	if (copy_from_user(&ax25_ctl, arg, sizeof(ax25_ctl)))
 		return -EFAULT;
 
-	if ((ax25_dev = ax25_addr_ax25dev(&ax25_ctl.port_addr)) == NULL)
-		return -ENODEV;
-
 	if (ax25_ctl.digi_count > AX25_MAX_DIGIS)
 		return -EINVAL;
 
 	if (ax25_ctl.arg > ULONG_MAX / HZ && ax25_ctl.cmd != AX25_KILL)
 		return -EINVAL;
 
+	ax25_dev = ax25_addr_ax25dev(&ax25_ctl.port_addr);
+	if (!ax25_dev)
+		return -ENODEV;
+
 	digi.ndigi = ax25_ctl.digi_count;
 	for (k = 0; k < digi.ndigi; k++)
 		digi.calls[k] = ax25_ctl.digi_addr[k];
 
-	if ((ax25 = ax25_find_cb(&ax25_ctl.source_addr, &ax25_ctl.dest_addr, &digi, ax25_dev->dev)) == NULL)
+	ax25 = ax25_find_cb(&ax25_ctl.source_addr, &ax25_ctl.dest_addr, &digi, ax25_dev->dev);
+	if (!ax25) {
+		ax25_dev_put(ax25_dev);
 		return -ENOTCONN;
+	}
 
 	switch (ax25_ctl.cmd) {
 	case AX25_KILL:
diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c
index 770b787fb7b..d2a244e1c26 100644
--- a/net/ax25/ax25_dev.c
+++ b/net/ax25/ax25_dev.c
@@ -85,8 +85,8 @@  void ax25_dev_device_up(struct net_device *dev)
 	spin_lock_bh(&ax25_dev_lock);
 	ax25_dev->next = ax25_dev_list;
 	ax25_dev_list  = ax25_dev;
-	ax25_dev_hold(ax25_dev);
 	spin_unlock_bh(&ax25_dev_lock);
+	ax25_dev_hold(ax25_dev);
 
 	ax25_register_dev_sysctl(ax25_dev);
 }
@@ -115,8 +115,8 @@  void ax25_dev_device_down(struct net_device *dev)
 
 	if ((s = ax25_dev_list) == ax25_dev) {
 		ax25_dev_list = s->next;
-		ax25_dev_put(ax25_dev);
 		spin_unlock_bh(&ax25_dev_lock);
+		ax25_dev_put(ax25_dev);
 		dev->ax25_ptr = NULL;
 		dev_put_track(dev, &ax25_dev->dev_tracker);
 		ax25_dev_put(ax25_dev);
@@ -126,8 +126,8 @@  void ax25_dev_device_down(struct net_device *dev)
 	while (s != NULL && s->next != NULL) {
 		if (s->next == ax25_dev) {
 			s->next = ax25_dev->next;
-			ax25_dev_put(ax25_dev);
 			spin_unlock_bh(&ax25_dev_lock);
+			ax25_dev_put(ax25_dev);
 			dev->ax25_ptr = NULL;
 			dev_put_track(dev, &ax25_dev->dev_tracker);
 			ax25_dev_put(ax25_dev);
@@ -150,25 +150,35 @@  int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 
 	switch (cmd) {
 	case SIOCAX25ADDFWD:
-		if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
+		fwd_dev = ax25_addr_ax25dev(&fwd->port_to);
+		if (!fwd_dev) {
+			ax25_dev_put(ax25_dev);
 			return -EINVAL;
-		if (ax25_dev->forward != NULL)
+		}
+		if (ax25_dev->forward) {
+			ax25_dev_put(fwd_dev);
+			ax25_dev_put(ax25_dev);
 			return -EINVAL;
+		}
 		ax25_dev->forward = fwd_dev->dev;
 		ax25_dev_put(fwd_dev);
+		ax25_dev_put(ax25_dev);
 		break;
 
 	case SIOCAX25DELFWD:
-		if (ax25_dev->forward == NULL)
+		if (!ax25_dev->forward) {
+			ax25_dev_put(ax25_dev);
 			return -EINVAL;
+		}
 		ax25_dev->forward = NULL;
+		ax25_dev_put(ax25_dev);
 		break;
 
 	default:
+		ax25_dev_put(ax25_dev);
 		return -EINVAL;
 	}
 
-	ax25_dev_put(ax25_dev);
 	return 0;
 }
 
diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
index 1e32693833e..9751207f775 100644
--- a/net/ax25/ax25_route.c
+++ b/net/ax25/ax25_route.c
@@ -75,11 +75,13 @@  static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
 	ax25_dev *ax25_dev;
 	int i;
 
-	if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
-		return -EINVAL;
 	if (route->digi_count > AX25_MAX_DIGIS)
 		return -EINVAL;
 
+	ax25_dev = ax25_addr_ax25dev(&route->port_addr);
+	if (!ax25_dev)
+		return -EINVAL;
+
 	write_lock_bh(&ax25_route_lock);
 
 	ax25_rt = ax25_route_list;
@@ -91,6 +93,7 @@  static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
 			if (route->digi_count != 0) {
 				if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
 					write_unlock_bh(&ax25_route_lock);
+					ax25_dev_put(ax25_dev);
 					return -ENOMEM;
 				}
 				ax25_rt->digipeat->lastrepeat = -1;
@@ -101,6 +104,7 @@  static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
 				}
 			}
 			write_unlock_bh(&ax25_route_lock);
+			ax25_dev_put(ax25_dev);
 			return 0;
 		}
 		ax25_rt = ax25_rt->next;
@@ -108,6 +112,7 @@  static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
 
 	if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {
 		write_unlock_bh(&ax25_route_lock);
+		ax25_dev_put(ax25_dev);
 		return -ENOMEM;
 	}
 
@@ -116,11 +121,11 @@  static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
 	ax25_rt->dev          = ax25_dev->dev;
 	ax25_rt->digipeat     = NULL;
 	ax25_rt->ip_mode      = ' ';
-	ax25_dev_put(ax25_dev);
 	if (route->digi_count != 0) {
 		if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
 			write_unlock_bh(&ax25_route_lock);
 			kfree(ax25_rt);
+			ax25_dev_put(ax25_dev);
 			return -ENOMEM;
 		}
 		ax25_rt->digipeat->lastrepeat = -1;
@@ -133,6 +138,7 @@  static int __must_check ax25_rt_add(struct ax25_routes_struct *route)
 	ax25_rt->next   = ax25_route_list;
 	ax25_route_list = ax25_rt;
 	write_unlock_bh(&ax25_route_lock);
+	ax25_dev_put(ax25_dev);
 
 	return 0;
 }
@@ -173,8 +179,8 @@  static int ax25_rt_del(struct ax25_routes_struct *route)
 			}
 		}
 	}
-	ax25_dev_put(ax25_dev);
 	write_unlock_bh(&ax25_route_lock);
+	ax25_dev_put(ax25_dev);
 
 	return 0;
 }
@@ -216,8 +222,8 @@  static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
 	}
 
 out:
-	ax25_dev_put(ax25_dev);
 	write_unlock_bh(&ax25_route_lock);
+	ax25_dev_put(ax25_dev);
 	return err;
 }