On Thu, Apr 30, 2026 at 09:38:44AM -0700, Jacob Keller wrote: > On 4/29/2026 12:42 AM, Larysa Zaremba wrote: > > Based on the following feedback from Sashiko (received for iXD phase 1 > > patchset, but valid for the net tree): > > > > "Is the bounds check xn_params.recv_mem.iov_len < lut_buf_size sufficient? > > Since lut_buf_size only represents the size of the array elements, should > > this check instead verify that the payload is at least > > sizeof(struct virtchnl2_rss_lut) + lut_buf_size? > > > > [...] > > > > Does memcpy copy the correct amount of data here? rss_lut_size stores the > > number of 32-bit entries, not the size in bytes. Should it use > > lut_buf_size or rss_data->rss_lut_size * sizeof(u32) instead?" > > > > After inspecting the code, it was concluded that RSS memcpy size is in fact > > 4 times smaller than it has to be, since a single array entry in a u32, and > > rss_data->rss_lut_size is clearly used as an array size. Required Rx buffer > > size is also too small, but this is a common issue in the idpf code. > > > > Use a full buffer size (lut_buf_size) instead of the array length > > (rss_data->rss_lut_size) when doing memcpy of RSS lookup table. > > While at it, increase required Rx buffer size to a whole flex-array > > containing structure instead of just the array. > > > > Link: > > https://sashiko.dev/#/patchset/20260323174052.5355-1-larysa.zaremba%40intel.com?part=8 > > Fixes: 95af467d9a4e ("idpf: configure resources for RX queues") > > Reviewed-by: Aleksandr Loktionov <[email protected]> > > Signed-off-by: Larysa Zaremba <[email protected]> > > --- > > drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c > > b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c > > index be66f9b2e101..a97d2e9b54d4 100644 > > --- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c > > +++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c > > @@ -2916,7 +2916,7 @@ int idpf_send_get_set_rss_lut_msg(struct idpf_adapter > > *adapter, > > return -EIO; > > > > lut_buf_size = le16_to_cpu(recv_rl->lut_entries) * sizeof(u32); > > - if (reply_sz < lut_buf_size) > > + if (reply_sz < lut_buf_size + sizeof(struct virtchnl2_rss_lut)) > > This feels like it should be using struct_size or flex_array_size... >
struct_size() does not really fit here, as lut_buf_size is needed later for flex-array-only memcpy, but flex_array_size() I can use. > > return -EIO; > > > > /* size didn't change, we can reuse existing lut buf */ > > @@ -2933,7 +2933,7 @@ int idpf_send_get_set_rss_lut_msg(struct idpf_adapter > > *adapter, > > } > > > > do_memcpy: > > - memcpy(rss_data->rss_lut, recv_rl->lut, rss_data->rss_lut_size); > > + memcpy(rss_data->rss_lut, recv_rl->lut, lut_buf_size); > > > > return 0; > > } >
