On 10/29/2019 01:06, coverity-bot wrote:
Hello!
This is an experimental automated report about issues detected by Coverity
from a scan of next-20191025 as part of the linux-next weekly scan project:
https://scan.coverity.com/projects/linux-next-weekly-scan
You're getting this email because you were associated with the identified
lines of code (noted below) that were touched by recent commits:
7f839684c5c4 ("igc: Add set_rx_mode support")
Coverity reported the following:
*** CID 1487361: Integer handling issues (BAD_SHIFT)
/drivers/net/ethernet/intel/igc/igc_mac.c: 851 in igc_hash_mc_addr()
845 break;
846 case 3:
847 bit_shift += 4;
848 break;
849 }
850
vvv CID 1487361: Integer handling issues (BAD_SHIFT)
vvv In expression "mc_addr[4] >> 8 - bit_shift", right shifting "mc_addr[4]" by more than 7 bits always yields zero. The shift amount, "8 - bit_shift", is 8.
851 hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) |
852 (((u16)mc_addr[5]) << bit_shift)));
853
854 return hash_value;
855 }
856
If this is a false positive, please let us know so we can mark it as
such, or teach the Coverity rules to be smarter. If not, please make
sure fixes get into linux-next. :) For patches fixing this, please
include:
We will provide a fix for multicast table array hashing.
Thanks,
Sasha
Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx>
Addresses-Coverity-ID: 1487361 ("Integer handling issues")
Fixes: 7f839684c5c4 ("igc: Add set_rx_mode support")
Thanks for your attention!
