Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Duoming Zhou 418993bbaa ax25: add refcount in ax25_dev to avoid UAF bugs ... commit d01ffb9eee4af165d83b08dd73ebdf9fe94a519b upstream. If we dereference ax25_dev after we call kfree(ax25_dev) in ax25_dev_device_down(), it will lead to concurrency UAF bugs. There are eight syscall functions suffer from UAF bugs, include ax25_bind(), ax25_release(), ax25_connect(), ax25_ioctl(), ax25_getname(), ax25_sendmsg(), ax25_getsockopt() and ax25_info_show(). One of the concurrency UAF can be shown as below: (USE) | (FREE) | ax25_device_event | ax25_dev_device_down ax25_bind | ... ... | kfree(ax25_dev) ax25_fillin_cb() | ... ax25_fillin_cb_from_dev() | ... | The root cause of UAF bugs is that kfree(ax25_dev) in ax25_dev_device_down() is not protected by any locks. When ax25_dev, which there are still pointers point to, is released, the concurrency UAF bug will happen. This patch introduces refcount into ax25_dev in order to guarantee that there are no pointers point to it when ax25_dev is released. Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> [OP: backport to 5.4: adjusted context] Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-04-20 09:19:39 +02:00
..
af_ax25.c	ax25: add refcount in ax25_dev to avoid UAF bugs	2022-04-20 09:19:39 +02:00
ax25_addr.c
ax25_dev.c	ax25: add refcount in ax25_dev to avoid UAF bugs	2022-04-20 09:19:39 +02:00
ax25_ds_in.c
ax25_ds_subr.c
ax25_ds_timer.c
ax25_iface.c
ax25_in.c
ax25_ip.c
ax25_out.c
ax25_route.c	ax25: add refcount in ax25_dev to avoid UAF bugs	2022-04-20 09:19:39 +02:00
ax25_std_in.c
ax25_std_subr.c
ax25_std_timer.c
ax25_subr.c
ax25_timer.c
ax25_uid.c
Kconfig
Makefile
sysctl_net_ax25.c
TODO