| Message ID | 53C28335.9090902@kristov.de |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
On Sun, Jul 13, 2014 at 3:01 PM, Christoph Schulz <develop@kristov.de> wrote: > From: Christoph Schulz <develop@kristov.de> > > Commit 568f194e8bd16c353ad50f9ab95d98b20578a39d ("net: ppp: use > sk_unattached_filter api") causes sk_chk_filter() to be called twice when > setting a PPP pass or active filter. This applies to both the generic PPP > subsystem implemented by drivers/net/ppp/ppp_generic.c and the ISDN PPP > subsystem implemented by drivers/isdn/i4l/isdn_ppp.c. The first call is from > within get_filter(). The second one is through the call chain > > ppp_ioctl() or isdn_ppp_ioctl() > --> sk_unattached_filter_create() > --> __sk_prepare_filter() > --> sk_chk_filter() > > The first call from within get_filter() should be deleted as get_filter() is > called just before calling sk_unattached_filter_create() later on, which > eventually calls sk_chk_filter() anyway. > > For 3.15.x, this proposed change is a bugfix rather than a pure optimization as > in that branch, sk_chk_filter() may replace filter codes by other codes which > are not recognized when executing sk_chk_filter() a second time. So with > 3.15.x, if sk_chk_filter() is called twice, the second invocation may yield > EINVAL (this depends on the filter codes found in the filter to be set, but > because the replacement is done for frequently used codes, this is almost > always the case). The net effect is that setting pass and/or active PPP filters > does not work anymore, since sk_unattached_filter_create() always returns > EINVAL due to the second call to sk_chk_filter(), regardless whether the filter > was originally sane or not. > > Signed-off-by: Christoph Schulz <develop@kristov.de> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Thank you for fixing it. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 07/13/2014 03:01 PM, Christoph Schulz wrote: > From: Christoph Schulz <develop@kristov.de> > > Commit 568f194e8bd16c353ad50f9ab95d98b20578a39d ("net: ppp: use > sk_unattached_filter api") causes sk_chk_filter() to be called twice when > setting a PPP pass or active filter. This applies to both the generic PPP > subsystem implemented by drivers/net/ppp/ppp_generic.c and the ISDN PPP > subsystem implemented by drivers/isdn/i4l/isdn_ppp.c. The first call is from > within get_filter(). The second one is through the call chain > > ppp_ioctl() or isdn_ppp_ioctl() > --> sk_unattached_filter_create() > --> __sk_prepare_filter() > --> sk_chk_filter() > > The first call from within get_filter() should be deleted as get_filter() is > called just before calling sk_unattached_filter_create() later on, which > eventually calls sk_chk_filter() anyway. > > For 3.15.x, this proposed change is a bugfix rather than a pure optimization as > in that branch, sk_chk_filter() may replace filter codes by other codes which > are not recognized when executing sk_chk_filter() a second time. So with > 3.15.x, if sk_chk_filter() is called twice, the second invocation may yield > EINVAL (this depends on the filter codes found in the filter to be set, but > because the replacement is done for frequently used codes, this is almost > always the case). The net effect is that setting pass and/or active PPP filters > does not work anymore, since sk_unattached_filter_create() always returns > EINVAL due to the second call to sk_chk_filter(), regardless whether the filter > was originally sane or not. > > Signed-off-by: Christoph Schulz <develop@kristov.de> Looking at [1]'s mbox, it seems to me your patch is corrupted by your email client (the last chunk not recognized) ... perhaps try to send it by using git-send-email(1). Other than that, it's fine. [1] http://patchwork.ozlabs.org/patch/369404/ -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c index 61ac632..a333b7f 100644 --- a/drivers/isdn/i4l/isdn_ppp.c +++ b/drivers/isdn/i4l/isdn_ppp.c @@ -442,7 +442,7 @@ static int get_filter(void __user *arg, struct sock_filter **p) { struct sock_fprog uprog; struct sock_filter *code = NULL; - int len, err; + int len; if (copy_from_user(&uprog, arg, sizeof(uprog))) return -EFAULT; @@ -458,12 +458,6 @@ static int get_filter(void __user *arg, struct sock_filter **p) if (IS_ERR(code)) return PTR_ERR(code); - err = sk_chk_filter(code, uprog.len); - if (err) { - kfree(code); - return err; - } - *p = code; return uprog.len; } diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 91d6c12..e2f20f8 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -539,7 +539,7 @@ static int get_filter(void __user *arg, struct sock_filter **p) { struct sock_fprog uprog; struct sock_filter *code = NULL; - int len, err; + int len; if (copy_from_user(&uprog, arg, sizeof(uprog))) return -EFAULT; @@ -554,12 +554,6 @@ static int get_filter(void __user *arg, struct sock_filter **p)