From: Colin King <colin.king@canonical.com>
To: Derek Chickles <dchickles@marvell.com>,
Satanand Burla <sburla@marvell.com>,
Felix Manlunas <fmanlunas@marvell.com>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Raghu Vatsavayi <rvatsavayi@caviumnetworks.com>,
netdev@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] liquidio: Fix unintented sign extension of a left shift of a u16
Date: Wed, 7 Apr 2021 11:12:48 +0100 [thread overview]
Message-ID: <20210407101248.485307-1-colin.king@canonical.com> (raw)
From: Colin Ian King <colin.king@canonical.com>
The macro CN23XX_PEM_BAR1_INDEX_REG is being used to shift oct->pcie_port
(a u16) left 24 places. There are two subtle issues here, first the
shift gets promoted to an signed int and then sign extended to a u64.
If oct->pcie_port is 0x80 or more then the upper bits get sign extended
to 1. Secondly shfiting a u16 24 bits will lead to an overflow so it
needs to be cast to a u64 for all the bits to not overflow.
It is entirely possible that the u16 port value is never large enough
for this to fail, but it is useful to fix unintended overflows such
as this.
Fix this by casting the port parameter to the macro to a u64 before
the shift.
Addresses-Coverity: ("Unintended sign extension")
Fixes: 5bc67f587ba7 ("liquidio: CN23XX register definitions")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/net/ethernet/cavium/liquidio/cn23xx_pf_regs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_regs.h b/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_regs.h
index e6d4ad99cc38..92c27b148176 100644
--- a/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_regs.h
+++ b/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_regs.h
@@ -521,7 +521,7 @@
#define CN23XX_BAR1_INDEX_OFFSET 3
#define CN23XX_PEM_BAR1_INDEX_REG(port, idx) \
- (CN23XX_PEM_BAR1_INDEX_START + ((port) << CN23XX_PEM_OFFSET) + \
+ (CN23XX_PEM_BAR1_INDEX_START + (((u64)port) << CN23XX_PEM_OFFSET) + \
((idx) << CN23XX_BAR1_INDEX_OFFSET))
/*############################ DPI #########################*/
--
2.30.2
next reply other threads:[~2021-04-07 10:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-07 10:12 Colin King [this message]
2021-04-07 22:10 ` [PATCH] liquidio: Fix unintented sign extension of a left shift of a u16 patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210407101248.485307-1-colin.king@canonical.com \
--to=colin.king@canonical.com \
--cc=davem@davemloft.net \
--cc=dchickles@marvell.com \
--cc=fmanlunas@marvell.com \
--cc=kernel-janitors@vger.kernel.org \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=rvatsavayi@caviumnetworks.com \
--cc=sburla@marvell.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).