octeontx2-af: initialize lmac_bmap in rvu_mcs_set_lmac_bmap()

[PATCH net] octeontx2-af: initialize lmac_bmap in rvu_mcs_set_lmac_bmap()

Posted by Karl Mehltretter 1 month, 2 weeks ago

rvu_mcs_set_lmac_bmap() declares lmac_bmap without initializing it and
only sets bits for valid lmacs with set_bit(), which ORs into the word
without clearing it first. Bits for invalid or skipped ports keep
whatever was on the stack, and the garbage is stored into
mcs->hw->lmac_bmap.

Initialize lmac_bmap to 0 so only valid lmacs are marked.

Found with Clang's -Wconditional-uninitialized.

Fixes: ca7f49ff8846 ("octeontx2-af: cn10k: Introduce driver for macsec block.")
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
---
 drivers/net/ethernet/marvell/octeontx2/af/mcs_rvu_if.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/af/mcs_rvu_if.c b/drivers/net/ethernet/marvell/octeontx2/af/mcs_rvu_if.c
index d98b49f47970b..fce22e314cac0 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/mcs_rvu_if.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/mcs_rvu_if.c
@@ -856,7 +856,7 @@ int rvu_mbox_handler_mcs_ctrl_pkt_rule_write(struct rvu *rvu,
 static void rvu_mcs_set_lmac_bmap(struct rvu *rvu)
 {
 	struct mcs *mcs = mcs_get_pdata(0);
-	unsigned long lmac_bmap;
+	unsigned long lmac_bmap = 0;
 	int cgx, lmac, port;
 
 	for (port = 0; port < mcs->hw->lmac_cnt; port++) {
-- 
2.53.0

Re: [PATCH net] octeontx2-af: initialize lmac_bmap in rvu_mcs_set_lmac_bmap()

Posted by Jakub Kicinski 1 month, 1 week ago

On Wed, 12 Aug 2026 08:07:30 +0200 Karl Mehltretter wrote:
> rvu_mcs_set_lmac_bmap() declares lmac_bmap without initializing it and
> only sets bits for valid lmacs with set_bit(), which ORs into the word
> without clearing it first. Bits for invalid or skipped ports keep
> whatever was on the stack, and the garbage is stored into
> mcs->hw->lmac_bmap.
> 
> Initialize lmac_bmap to 0 so only valid lmacs are marked.
> 
> Found with Clang's -Wconditional-uninitialized.

Applied, thanks!

Re: [PATCH net] octeontx2-af: initialize lmac_bmap in rvu_mcs_set_lmac_bmap()

Posted by Simon Horman 1 month, 2 weeks ago

On Wed, Aug 12, 2026 at 08:07:30AM +0200, Karl Mehltretter wrote:
> rvu_mcs_set_lmac_bmap() declares lmac_bmap without initializing it and
> only sets bits for valid lmacs with set_bit(), which ORs into the word
> without clearing it first. Bits for invalid or skipped ports keep
> whatever was on the stack, and the garbage is stored into
> mcs->hw->lmac_bmap.
> 
> Initialize lmac_bmap to 0 so only valid lmacs are marked.
> 
> Found with Clang's -Wconditional-uninitialized.
> 
> Fixes: ca7f49ff8846 ("octeontx2-af: cn10k: Introduce driver for macsec block.")
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net] octeontx2-af: initialize lmac_bmap in rvu_mcs_set_lmac_bmap()

Posted by Ratheesh Kannoth 1 month, 2 weeks ago

On 2026-08-12 at 11:37:30, Karl Mehltretter (kmehltretter@gmail.com) wrote:
> rvu_mcs_set_lmac_bmap() declares lmac_bmap without initializing it and
> only sets bits for valid lmacs with set_bit(), which ORs into the word
> without clearing it first. Bits for invalid or skipped ports keep
> whatever was on the stack, and the garbage is stored into
> mcs->hw->lmac_bmap.
>
> Initialize lmac_bmap to 0 so only valid lmacs are marked.
>
> Found with Clang's -Wconditional-uninitialized.
>
> Fixes: ca7f49ff8846 ("octeontx2-af: cn10k: Introduce driver for macsec block.")
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>

Thank you.

Reviewed-by: Ratheesh Kannoth <rkannoth@marvell.com>