[PATCH] cxgb4: Fix unintentional sign extension issues

[PATCH] cxgb4: Fix unintentional sign extension issues

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The shifting of the u8 integers f->fs.nat_lip[] by 24 bits to
the left will be promoted to a 32 bit signed int and then
sign-extended to a u64. In the event that the top bit of the u8
is set then all then all the upper 32 bits of the u64 end up as
also being set because of the sign-extension. Fix this by
casting the u8 values to a u64 before the 24 bit left shift.

Addresses-Coverity: ("Unintended sign extension")
Fixes: 12b276fbf6e0 ("cxgb4: add support to create hash filters")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 .../net/ethernet/chelsio/cxgb4/cxgb4_filter.c | 22 +++++++++----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_filter.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_filter.c
index b1cae5a19839..2f70f02207b2 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_filter.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_filter.c
@@ -174,31 +174,31 @@ static void set_nat_params(struct adapter *adap, struct filter_entry *f,
 				      WORD_MASK, f->fs.nat_lip[15] |
 				      f->fs.nat_lip[14] << 8 |
 				      f->fs.nat_lip[13] << 16 |
-				      f->fs.nat_lip[12] << 24, 1);
+				      (u64)f->fs.nat_lip[12] << 24, 1);
 
 			set_tcb_field(adap, f, tid, TCB_SND_UNA_RAW_W + 1,
 				      WORD_MASK, f->fs.nat_lip[11] |
 				      f->fs.nat_lip[10] << 8 |
 				      f->fs.nat_lip[9] << 16 |
-				      f->fs.nat_lip[8] << 24, 1);
+				      (u64)f->fs.nat_lip[8] << 24, 1);
 
 			set_tcb_field(adap, f, tid, TCB_SND_UNA_RAW_W + 2,
 				      WORD_MASK, f->fs.nat_lip[7] |
 				      f->fs.nat_lip[6] << 8 |
 				      f->fs.nat_lip[5] << 16 |
-				      f->fs.nat_lip[4] << 24, 1);
+				      (u64)f->fs.nat_lip[4] << 24, 1);
 
 			set_tcb_field(adap, f, tid, TCB_SND_UNA_RAW_W + 3,
 				      WORD_MASK, f->fs.nat_lip[3] |
 				      f->fs.nat_lip[2] << 8 |
 				      f->fs.nat_lip[1] << 16 |
-				      f->fs.nat_lip[0] << 24, 1);
+				      (u64)f->fs.nat_lip[0] << 24, 1);
 		} else {
 			set_tcb_field(adap, f, tid, TCB_RX_FRAG3_LEN_RAW_W,
 				      WORD_MASK, f->fs.nat_lip[3] |
 				      f->fs.nat_lip[2] << 8 |
 				      f->fs.nat_lip[1] << 16 |
-				      f->fs.nat_lip[0] << 24, 1);
+				      (u64)f->fs.nat_lip[0] << 25, 1);
 		}
 	}
 
@@ -208,25 +208,25 @@ static void set_nat_params(struct adapter *adap, struct filter_entry *f,
 				      WORD_MASK, f->fs.nat_fip[15] |
 				      f->fs.nat_fip[14] << 8 |
 				      f->fs.nat_fip[13] << 16 |
-				      f->fs.nat_fip[12] << 24, 1);
+				      (u64)f->fs.nat_fip[12] << 24, 1);
 
 			set_tcb_field(adap, f, tid, TCB_RX_FRAG2_PTR_RAW_W + 1,
 				      WORD_MASK, f->fs.nat_fip[11] |
 				      f->fs.nat_fip[10] << 8 |
 				      f->fs.nat_fip[9] << 16 |
-				      f->fs.nat_fip[8] << 24, 1);
+				      (u64)f->fs.nat_fip[8] << 24, 1);
 
 			set_tcb_field(adap, f, tid, TCB_RX_FRAG2_PTR_RAW_W + 2,
 				      WORD_MASK, f->fs.nat_fip[7] |
 				      f->fs.nat_fip[6] << 8 |
 				      f->fs.nat_fip[5] << 16 |
-				      f->fs.nat_fip[4] << 24, 1);
+				      (u64)f->fs.nat_fip[4] << 24, 1);
 
 			set_tcb_field(adap, f, tid, TCB_RX_FRAG2_PTR_RAW_W + 3,
 				      WORD_MASK, f->fs.nat_fip[3] |
 				      f->fs.nat_fip[2] << 8 |
 				      f->fs.nat_fip[1] << 16 |
-				      f->fs.nat_fip[0] << 24, 1);
+				      (u64)f->fs.nat_fip[0] << 24, 1);
 
 		} else {
 			set_tcb_field(adap, f, tid,
@@ -234,13 +234,13 @@ static void set_nat_params(struct adapter *adap, struct filter_entry *f,
 				      WORD_MASK, f->fs.nat_fip[3] |
 				      f->fs.nat_fip[2] << 8 |
 				      f->fs.nat_fip[1] << 16 |
-				      f->fs.nat_fip[0] << 24, 1);
+				      (u64)f->fs.nat_fip[0] << 24, 1);
 		}
 	}
 
 	set_tcb_field(adap, f, tid, TCB_PDU_HDR_LEN_W, WORD_MASK,
 		      (dp ? (nat_lp[1] | nat_lp[0] << 8) : 0) |
-		      (sp ? (nat_fp[1] << 16 | nat_fp[0] << 24) : 0),
+		      (sp ? (nat_fp[1] << 16 | (u64)nat_fp[0] << 24) : 0),
 		      1);
 }
 
-- 
2.30.2

Re: [PATCH] cxgb4: Fix unintentional sign extension issues

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Fri,  9 Apr 2021 12:08:57 +0100 you wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The shifting of the u8 integers f->fs.nat_lip[] by 24 bits to
> the left will be promoted to a 32 bit signed int and then
> sign-extended to a u64. In the event that the top bit of the u8
> is set then all then all the upper 32 bits of the u64 end up as
> also being set because of the sign-extension. Fix this by
> casting the u8 values to a u64 before the 24 bit left shift.
> 
> [...]

Here is the summary with links:
  - cxgb4: Fix unintentional sign extension issues
    https://git.kernel.org/netdev/net-next/c/dd2c79677375

You are awesome, thank you!
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