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| author | Duoming Zhou <duoming@zju.edu.cn> | 2022-02-03 16:08:11 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-02-03 23:20:36 +0100 |
| commit | 87563a043cef044fed5db7967a75741cc16ad2b1 (patch) | |
| tree | 4afe345736b9d1e946ddd4ad5fdbc349b046900f /net/ax25/ax25_dev.c | |
| parent | net: stmmac: ensure PTP time register reads are consistent (diff) | |
| download | linux-87563a043cef044fed5db7967a75741cc16ad2b1.tar.xz linux-87563a043cef044fed5db7967a75741cc16ad2b1.zip | |
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 <duoming@zju.edu.cn>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220203150811.42256-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ax25/ax25_dev.c')
| -rw-r--r-- | net/ax25/ax25_dev.c | 24 |
1 files changed, 17 insertions, 7 deletions
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; } |