diff options
| author | Christoph Hellwig | 2020-07-30 18:09:00 +0200 |
|---|---|---|
| committer | Daniel Borkmann | 2020-07-31 01:07:32 +0200 |
| commit | 4f010246b4087ab931b060481014ec110e6a8a46 (patch) | |
| tree | e454d2a5f3dad27c81eaaba95127c681cdb6cce4 | |
| parent | 0ba58348414eb10249480635545758b40b3c33b6 (diff) | |
net/bpfilter: Initialize pos in __bpfilter_process_sockopt
__bpfilter_process_sockopt never initialized the pos variable passed
to the pipe write. This has been mostly harmless in the past as pipes
ignore the offset, but the switch to kernel_write now verified the
position, which can lead to a failure depending on the exact stack
initialization pattern. Initialize the variable to zero to make
rw_verify_area happy.
Fixes: 6955a76fbcd5 ("bpfilter: switch to kernel_write")
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Reported-by: Rodrigo Madera <rodrigo.madera@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Rodrigo Madera <rodrigo.madera@gmail.com>
Tested-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/bpf/20200730160900.187157-1-hch@lst.de
| -rw-r--r-- | net/bpfilter/bpfilter_kern.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index c0f0990f30b6..cfb27166bfd7 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -39,7 +39,7 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, { struct mbox_request req; struct mbox_reply reply; - loff_t pos; + loff_t pos = 0; ssize_t n; int ret = -EFAULT; |