diff options
author | Duoming Zhou <duoming@zju.edu.cn> | 2022-04-05 21:22:06 +0800 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2022-04-06 23:00:16 -0700 |
commit | ec4eb8a86ade4d22633e1da2a7d85a846b7d1798 (patch) | |
tree | 83177045d62c3294479a81517c3a3ca68636b7a2 /tools/bpf/bpftool | |
parent | 8e9d0d7a76c556e8b73289555950917db13d2077 (diff) | |
download | linux-ec4eb8a86ade4d22633e1da2a7d85a846b7d1798.tar.bz2 |
drivers: net: slip: fix NPD bug in sl_tx_timeout()
When a slip driver is detaching, the slip_close() will act to
cleanup necessary resources and sl->tty is set to NULL in
slip_close(). Meanwhile, the packet we transmit is blocked,
sl_tx_timeout() will be called. Although slip_close() and
sl_tx_timeout() use sl->lock to synchronize, we don`t judge
whether sl->tty equals to NULL in sl_tx_timeout() and the
null pointer dereference bug will happen.
(Thread 1) | (Thread 2)
| slip_close()
| spin_lock_bh(&sl->lock)
| ...
... | sl->tty = NULL //(1)
sl_tx_timeout() | spin_unlock_bh(&sl->lock)
spin_lock(&sl->lock); |
... | ...
tty_chars_in_buffer(sl->tty)|
if (tty->ops->..) //(2) |
... | synchronize_rcu()
We set NULL to sl->tty in position (1) and dereference sl->tty
in position (2).
This patch adds check in sl_tx_timeout(). If sl->tty equals to
NULL, sl_tx_timeout() will goto out.
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20220405132206.55291-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools/bpf/bpftool')
0 files changed, 0 insertions, 0 deletions