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From: coverity-bot <>
To: Sasha Neftin <>
Cc: Jeff Kirsher <>,
	Aaron Brown <>,
	"Gustavo A. R. Silva" <>,
Subject: Coverity: igc_hash_mc_addr(): Integer handling issues
Date: Mon, 28 Oct 2019 16:06:15 -0700
Message-ID: <201910281606.99B58CD542@keescook> (raw)


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:

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     	}
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)));
854     	return hash_value;
855     }

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

Reported-by: coverity-bot <>
Addresses-Coverity-ID: 1487361 ("Integer handling issues")
Fixes: 7f839684c5c4 ("igc: Add set_rx_mode support")

Thanks for your attention!


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Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-28 23:06 coverity-bot [this message]
2019-10-30 16:17 ` Neftin, Sasha

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