| Message ID | tencent_8D19734F828DA6A5938DF1122F5DDC5DBC07@qq.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | wifi: ath6kl: Check that the read operation returns a data length of 0 | expand |
On Sun, Aug 25, 2024 at 03:10:03PM +0800, Edward Adam Davis wrote: > If the data length returned by the device is 0, the read operation > should be considered a failure. > > Reported-and-tested-by: syzbot+92c6dd14aaa230be6855@syzkaller.appspotmail.com > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > --- > drivers/net/wireless/ath/ath6kl/usb.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > index 5220809841a6..2a89bab81b24 100644 > --- a/drivers/net/wireless/ath/ath6kl/usb.c > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > @@ -1034,6 +1034,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) > ath6kl_err("Unable to read the bmi data from the device: %d\n", > ret); > return ret; > + } else { > + ath6kl_err("Actual read the bmi data length is 0 from the device\n"); > + return -EIO; Close, but not quite there. ath6kl_usb_submit_ctrl_in() needs to verify that the actual amount of data was read that was asked for. If a short read happens (or a long one), then an error needs to propagate out, not just 0. See the "note:" line in that function for what needs to be properly checked. hope this helps, greg k-h
On Sun, 25 Aug 2024 09:25:37 +0200, Greg KH wrote: > > If the data length returned by the device is 0, the read operation > > should be considered a failure. > > > > Reported-and-tested-by: syzbot+92c6dd14aaa230be6855@syzkaller.appspotmail.com > > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > > --- > > drivers/net/wireless/ath/ath6kl/usb.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > index 5220809841a6..2a89bab81b24 100644 > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > @@ -1034,6 +1034,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) > > ath6kl_err("Unable to read the bmi data from the device: %d\n", > > ret); > > return ret; > > + } else { > > + ath6kl_err("Actual read the bmi data length is 0 from the device\n"); > > + return -EIO; > > Close, but not quite there. ath6kl_usb_submit_ctrl_in() needs to verify > that the actual amount of data was read that was asked for. If a short > read happens (or a long one), then an error needs to propagate out, not > just 0. See the "note:" line in that function for what needs to be > properly checked. > > hope this helps, Thanks for your analysis. I have carefully read your analysis and I am not sure if the following understanding is appropriate: diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c index 2a89bab81b24..35884316a8c8 100644 --- a/drivers/net/wireless/ath/ath6kl/usb.c +++ b/drivers/net/wireless/ath/ath6kl/usb.c @@ -932,6 +932,15 @@ static int ath6kl_usb_submit_ctrl_in(struct ath6kl_usb *ar_usb, kfree(buf); + /* There are two types of read failure situations that need to be captured: + * 1. short read: ret < size && ret >= 0 + * 2. long read: ret > size + * */ + if (req == ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP && ret != size) { + ath6kl_warn("Actual read the data length is: %d, but input size is %d\n", ret, size); + return -EIO; + } + return 0; } BR, Edward
On Sun, Aug 25, 2024 at 04:14:17PM +0800, Edward Adam Davis wrote: > On Sun, 25 Aug 2024 09:25:37 +0200, Greg KH wrote: > > > If the data length returned by the device is 0, the read operation > > > should be considered a failure. > > > > > > Reported-and-tested-by: syzbot+92c6dd14aaa230be6855@syzkaller.appspotmail.com > > > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > > > --- > > > drivers/net/wireless/ath/ath6kl/usb.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > > index 5220809841a6..2a89bab81b24 100644 > > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > > @@ -1034,6 +1034,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) > > > ath6kl_err("Unable to read the bmi data from the device: %d\n", > > > ret); > > > return ret; > > > + } else { > > > + ath6kl_err("Actual read the bmi data length is 0 from the device\n"); > > > + return -EIO; > > > > Close, but not quite there. ath6kl_usb_submit_ctrl_in() needs to verify > > that the actual amount of data was read that was asked for. If a short > > read happens (or a long one), then an error needs to propagate out, not > > just 0. See the "note:" line in that function for what needs to be > > properly checked. > > > > hope this helps, > Thanks for your analysis. > I have carefully read your analysis and I am not sure if the following > understanding is appropriate: > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > index 2a89bab81b24..35884316a8c8 100644 > --- a/drivers/net/wireless/ath/ath6kl/usb.c > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > @@ -932,6 +932,15 @@ static int ath6kl_usb_submit_ctrl_in(struct ath6kl_usb *ar_usb, > > kfree(buf); First off, this should be using usb_control_msg_send() instead of having to roll their own buffer handling, right? > + /* There are two types of read failure situations that need to be captured: > + * 1. short read: ret < size && ret >= 0 > + * 2. long read: ret > size > + * */ > + if (req == ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP && ret != size) { > + ath6kl_warn("Actual read the data length is: %d, but input size is %d\n", ret, size); > + return -EIO; > + } If you switch to usb_control_msg_send() this logic gets a lot simpler. Perhaps do that instead? If not, then you need to check for "short writes" or zero writes, see the documentation for usb_control_msg() for what it returns. Your comment is not correct here, there are 3 different return "states" that you need to handle. And why are you caring about what the req type is? thanks, greg k-h
On Sun, 25 Aug 2024 10:34:00 +0200, Greg KH wrote: > On Sun, Aug 25, 2024 at 04:14:17PM +0800, Edward Adam Davis wrote: > > On Sun, 25 Aug 2024 09:25:37 +0200, Greg KH wrote: > > > > If the data length returned by the device is 0, the read operation > > > > should be considered a failure. > > > > > > > > Reported-and-tested-by: syzbot+92c6dd14aaa230be6855@syzkaller.appspotmail.com > > > > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > > > > --- > > > > drivers/net/wireless/ath/ath6kl/usb.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > > > index 5220809841a6..2a89bab81b24 100644 > > > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > > > @@ -1034,6 +1034,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) > > > > ath6kl_err("Unable to read the bmi data from the device: %d\n", > > > > ret); > > > > return ret; > > > > + } else { > > > > + ath6kl_err("Actual read the bmi data length is 0 from the device\n"); > > > > + return -EIO; > > > > > > Close, but not quite there. ath6kl_usb_submit_ctrl_in() needs to verify > > > that the actual amount of data was read that was asked for. If a short > > > read happens (or a long one), then an error needs to propagate out, not > > > just 0. See the "note:" line in that function for what needs to be > > > properly checked. > > > > > > hope this helps, > > Thanks for your analysis. > > I have carefully read your analysis and I am not sure if the following > > understanding is appropriate: > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > index 2a89bab81b24..35884316a8c8 100644 > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > @@ -932,6 +932,15 @@ static int ath6kl_usb_submit_ctrl_in(struct ath6kl_usb *ar_usb, > > > > kfree(buf); > > First off, this should be using usb_control_msg_send() instead of having > to roll their own buffer handling, right? I couldn't figure it out with what you said. ath6kl_usb_submit_ctrl_in() is similar to usb_control_msg_send(), both calling usb_control_msg() to communicate with USB devices. In the current issue, when executing an ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP read request, the length of the data returned from the device is 0, which is different from the expected length of the data to be read, resulting in a warning. ath6kl_usb_submit_ctrl_in()---> usb_control_msg()---> usb_internal_control_msg() usb_internal_control_msg() will return the length of the data returned from the device, usb_control_msg() return the length too, so in ath6kl_usb_submit_ctrl_in(), we can filter out incorrect data lengths by judging the value of ret, such as ret != Size situation. > > > + /* There are two types of read failure situations that need to be captured: > > + * 1. short read: ret < size && ret >= 0 > > + * 2. long read: ret > size > > + * */ > > + if (req == ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP && ret != size) { > > + ath6kl_warn("Actual read the data length is: %d, but input size is %d\n", ret, size); > > + return -EIO; > > + } > > If you switch to usb_control_msg_send() this logic gets a lot simpler. > Perhaps do that instead? > > If not, then you need to check for "short writes" or zero writes, see > the documentation for usb_control_msg() for what it returns. Your > comment is not correct here, there are 3 different return "states" that > you need to handle. > > And why are you caring about what the req type is? BR, Edward
On Sun, Aug 25, 2024 at 06:09:45PM +0800, Edward Adam Davis wrote: > On Sun, 25 Aug 2024 10:34:00 +0200, Greg KH wrote: > > On Sun, Aug 25, 2024 at 04:14:17PM +0800, Edward Adam Davis wrote: > > > On Sun, 25 Aug 2024 09:25:37 +0200, Greg KH wrote: > > > > > If the data length returned by the device is 0, the read operation > > > > > should be considered a failure. > > > > > > > > > > Reported-and-tested-by: syzbot+92c6dd14aaa230be6855@syzkaller.appspotmail.com > > > > > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > > > > > --- > > > > > drivers/net/wireless/ath/ath6kl/usb.c | 3 +++ > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > > > > index 5220809841a6..2a89bab81b24 100644 > > > > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > > > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > > > > @@ -1034,6 +1034,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) > > > > > ath6kl_err("Unable to read the bmi data from the device: %d\n", > > > > > ret); > > > > > return ret; > > > > > + } else { > > > > > + ath6kl_err("Actual read the bmi data length is 0 from the device\n"); > > > > > + return -EIO; > > > > > > > > Close, but not quite there. ath6kl_usb_submit_ctrl_in() needs to verify > > > > that the actual amount of data was read that was asked for. If a short > > > > read happens (or a long one), then an error needs to propagate out, not > > > > just 0. See the "note:" line in that function for what needs to be > > > > properly checked. > > > > > > > > hope this helps, > > > Thanks for your analysis. > > > I have carefully read your analysis and I am not sure if the following > > > understanding is appropriate: > > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > > index 2a89bab81b24..35884316a8c8 100644 > > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > > @@ -932,6 +932,15 @@ static int ath6kl_usb_submit_ctrl_in(struct ath6kl_usb *ar_usb, > > > > > > kfree(buf); > > > > First off, this should be using usb_control_msg_send() instead of having > > to roll their own buffer handling, right? > I couldn't figure it out with what you said. Meaning this kfree() should not be needed if you use usb_control_msg_send() (nor the allocation above it.) > ath6kl_usb_submit_ctrl_in() is similar to usb_control_msg_send(), > both calling usb_control_msg() to communicate with USB devices. Yes, it's close, but not quite the same. > In the current issue, when executing an ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP > read request, the length of the data returned from the device is 0, which > is different from the expected length of the data to be read, resulting in > a warning. > > ath6kl_usb_submit_ctrl_in()---> > usb_control_msg()---> > usb_internal_control_msg() > > usb_internal_control_msg() will return the length of the data returned from > the device, usb_control_msg() return the length too, so in ath6kl_usb_submit_ctrl_in(), > we can filter out incorrect data lengths by judging the value of ret, such > as ret != Size situation. Then just do that type of check for that type of read request in the code that does that call, not 2-3 layers deeper, no need for making this more complex than needed. Try removing both of these functions and just call usb functions directly. thanks, greg k-h
On Sun, 25 Aug 2024 13:25:56 +0200, Greg KH wrote: > On Sun, Aug 25, 2024 at 06:09:45PM +0800, Edward Adam Davis wrote: > > On Sun, 25 Aug 2024 10:34:00 +0200, Greg KH wrote: > > > On Sun, Aug 25, 2024 at 04:14:17PM +0800, Edward Adam Davis wrote: > > > > On Sun, 25 Aug 2024 09:25:37 +0200, Greg KH wrote: > > > > > > If the data length returned by the device is 0, the read operation > > > > > > should be considered a failure. > > > > > > > > > > > > Reported-and-tested-by: syzbot+92c6dd14aaa230be6855@syzkaller.appspotmail.com > > > > > > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > > > > > > --- > > > > > > drivers/net/wireless/ath/ath6kl/usb.c | 3 +++ > > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > > > > > index 5220809841a6..2a89bab81b24 100644 > > > > > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > > > > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > > > > > @@ -1034,6 +1034,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) > > > > > > ath6kl_err("Unable to read the bmi data from the device: %d\n", > > > > > > ret); > > > > > > return ret; > > > > > > + } else { > > > > > > + ath6kl_err("Actual read the bmi data length is 0 from the device\n"); > > > > > > + return -EIO; > > > > > > > > > > Close, but not quite there. ath6kl_usb_submit_ctrl_in() needs to verify > > > > > that the actual amount of data was read that was asked for. If a short > > > > > read happens (or a long one), then an error needs to propagate out, not > > > > > just 0. See the "note:" line in that function for what needs to be > > > > > properly checked. > > > > > > > > > > hope this helps, > > > > Thanks for your analysis. > > > > I have carefully read your analysis and I am not sure if the following > > > > understanding is appropriate: > > > > diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c > > > > index 2a89bab81b24..35884316a8c8 100644 > > > > --- a/drivers/net/wireless/ath/ath6kl/usb.c > > > > +++ b/drivers/net/wireless/ath/ath6kl/usb.c > > > > @@ -932,6 +932,15 @@ static int ath6kl_usb_submit_ctrl_in(struct ath6kl_usb *ar_usb, > > > > > > > > kfree(buf); > > > > > > First off, this should be using usb_control_msg_send() instead of having > > > to roll their own buffer handling, right? > > I couldn't figure it out with what you said. > > Meaning this kfree() should not be needed if you use > usb_control_msg_send() (nor the allocation above it.) > > > ath6kl_usb_submit_ctrl_in() is similar to usb_control_msg_send(), > > both calling usb_control_msg() to communicate with USB devices. > > Yes, it's close, but not quite the same. > > > In the current issue, when executing an ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP > > read request, the length of the data returned from the device is 0, which > > is different from the expected length of the data to be read, resulting in > > a warning. > > > > ath6kl_usb_submit_ctrl_in()---> > > usb_control_msg()---> > > usb_internal_control_msg() > > > > usb_internal_control_msg() will return the length of the data returned from > > the device, usb_control_msg() return the length too, so in ath6kl_usb_submit_ctrl_in(), > > we can filter out incorrect data lengths by judging the value of ret, such > > as ret != Size situation. > > Then just do that type of check for that type of read request in the > code that does that call, not 2-3 layers deeper, no need for making this > more complex than needed. > > Try removing both of these functions and just call usb functions > directly. I have tried following fix: diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c index 5220809841a6..dc1f89ebb740 100644 --- a/drivers/net/wireless/ath/ath6kl/usb.c +++ b/drivers/net/wireless/ath/ath6kl/usb.c @@ -1027,9 +1027,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) int ret; /* get response */ - ret = ath6kl_usb_submit_ctrl_in(ar_usb, - ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP, - 0, 0, buf, len); + ret = usb_control_msg_recv(ar_usb->udev, 0, ATH6KL_USB_CONTROL_REQ_RECV_BMI_RESP, + USB_DIR_IN | USB_TYPE_VENDOR | + USB_RECIP_DEVICE, 0, 0, buf, len, 2000, GFP_KERNEL); if (ret) { ath6kl_err("Unable to read the bmi data from the device: %d\n", ret); I researched usb_control_msg_recv(), It handles the abnormal length of the returned data, so using it directly can fix this warning. BR, Edward
diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c index 5220809841a6..2a89bab81b24 100644 --- a/drivers/net/wireless/ath/ath6kl/usb.c +++ b/drivers/net/wireless/ath/ath6kl/usb.c @@ -1034,6 +1034,9 @@ static int ath6kl_usb_bmi_read(struct ath6kl *ar, u8 *buf, u32 len) ath6kl_err("Unable to read the bmi data from the device: %d\n", ret); return ret; + } else { + ath6kl_err("Actual read the bmi data length is 0 from the device\n"); + return -EIO; } return 0;
If the data length returned by the device is 0, the read operation should be considered a failure. Reported-and-tested-by: syzbot+92c6dd14aaa230be6855@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> --- drivers/net/wireless/ath/ath6kl/usb.c | 3 +++ 1 file changed, 3 insertions(+)