From 87563a043cef044fed5db7967a75741cc16ad2b1 Mon Sep 17 00:00:00 2001 From: Duoming Zhou Date: Thu, 3 Feb 2022 23:08:11 +0800 Subject: ax25: fix reference count leaks of ax25_dev 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 Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/20220203150811.42256-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski --- net/ax25/af_ax25.c | 12 ++++++++---- net/ax25/ax25_dev.c | 24 +++++++++++++++++------- net/ax25/ax25_route.c | 16 +++++++++++----- 3 files changed, 36 insertions(+), 16 deletions(-) (limited to 'net/ax25') diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 32f61978ff29..3e49d28824ed 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 770b787fb7bb..d2a244e1c260 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 1e32693833e5..9751207f7757 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; } -- cgit