Messages in this thread | | | Date | Fri, 3 Nov 2023 11:23:16 -0700 | Subject | Re: [PATCH] Prevent out-of-bounds read/write in bcmasp_netfilt_rd and bcmasp_netfilt_wr | From | Justin Chen <> |
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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.
Thanks, Justin [unhandled content-type:application/pkcs7-signature]
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