Messages in this thread | | | Date | Fri, 3 Nov 2023 19:33:34 +0100 | From | Greg KH <> | Subject | Re: [PATCH] Prevent out-of-bounds read/write in bcmasp_netfilt_rd and bcmasp_netfilt_wr |
| |
On Fri, Nov 03, 2023 at 11:23:16AM -0700, Justin Chen wrote: > > > On 11/3/23 5:57 AM, Greg KH wrote: > > On Fri, Nov 03, 2023 at 05:57:48PM +0530, Yuran Pereira wrote: > > > The functions `bcmasp_netfilt_rd` and `bcmasp_netfilt_wr` both call > > > `bcmasp_netfilt_get_reg_offset` which, when it fails, returns `-EINVAL`. > > > This could lead to an out-of-bounds read or write when `rx_filter_core_rl` > > > or `rx_filter_core_wl` is called. > > > > > > This patch adds a check in both functions to return immediately if > > > `bcmasp_netfilt_get_reg_offset` fails. This prevents potential out-of-bounds read > > > or writes, and ensures that no undefined or buggy behavior would originate from > > > the failure of `bcmasp_netfilt_get_reg_offset`. > > > > > > Addresses-Coverity-IDs: 1544536 ("Out-of-bounds access") > > > Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com> > > > --- > > > drivers/net/ethernet/broadcom/asp2/bcmasp.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/net/ethernet/broadcom/asp2/bcmasp.c b/drivers/net/ethernet/broadcom/asp2/bcmasp.c > > > index 29b04a274d07..8b90b761bdec 100644 > > > --- a/drivers/net/ethernet/broadcom/asp2/bcmasp.c > > > +++ b/drivers/net/ethernet/broadcom/asp2/bcmasp.c > > > @@ -227,6 +227,8 @@ static void bcmasp_netfilt_wr(struct bcmasp_priv *priv, > > > reg_offset = bcmasp_netfilt_get_reg_offset(priv, nfilt, reg_type, > > > offset); > > > + if (reg_offset < 0) > > > + return; > > > rx_filter_core_wl(priv, val, reg_offset); > > > } > > > @@ -244,6 +246,8 @@ static u32 bcmasp_netfilt_rd(struct bcmasp_priv *priv, > > > reg_offset = bcmasp_netfilt_get_reg_offset(priv, nfilt, reg_type, > > > offset); > > > + if (reg_offset < 0) > > > + return 0; > > > > Shouldn't you return an error here? > > > > thanks > > > > greg k-h > > As long as offset is less than MAX_WAKE_FILTER_SIZE we don't need to worry > about error checking. This is already checked before we call > netfilt_get_reg_offset() in both cases. Instead of returning -EINVAL in > neffilt_get_reg_offset() lets return 0. This will silence the coverity > check. In practice we will never hit this logic.
Then don't change it, coverity is incorrect here.
greg k-h
| |