Commit d2848c77 authored by Wei Fang's avatar Wei Fang Committed by Wentao Guan
Browse files

net: enetc: fix the off-by-one issue in enetc_map_tx_buffs() 

stable inclusion
from stable-v6.6.81
commit 9561b0550c496aecc21f20261ea8d0d388fe69c4
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBYZED

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9561b0550c496aecc21f20261ea8d0d388fe69c4



--------------------------------

commit 39ab773e4c120f7f98d759415ccc2aca706bbc10 upstream.

When a DMA mapping error occurs while processing skb frags, it will free
one more tx_swbd than expected, so fix this off-by-one issue.

Fixes: d4fd0404 ("enetc: Introduce basic PF and VF ENETC ethernet drivers")
Cc: stable@vger.kernel.org
Suggested-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Suggested-by: default avatarMichal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: default avatarWei Fang <wei.fang@nxp.com>
Reviewed-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarClaudiu Manoil <claudiu.manoil@nxp.com>
Link: https://patch.msgid.link/20250224111251.1061098-2-wei.fang@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 9561b0550c496aecc21f20261ea8d0d388fe69c4)
Signed-off-by: default avatarWentao Guan <guanwentao@uniontech.com>
parent ec9492bc

drivers/net/ethernet/freescale/enetc/enetc.c

+19 −7
Original line number Diff line number Diff line
@@ -145,6 +145,24 @@ static int enetc_ptp_parse(struct sk_buff *skb, u8 *udp, 
	return 0;

}



/**

 * enetc_unwind_tx_frame() - Unwind the DMA mappings of a multi-buffer Tx frame

 * @tx_ring: Pointer to the Tx ring on which the buffer descriptors are located

 * @count: Number of Tx buffer descriptors which need to be unmapped

 * @i: Index of the last successfully mapped Tx buffer descriptor

 */

static void enetc_unwind_tx_frame(struct enetc_bdr *tx_ring, int count, int i)

{

	while (count--) {

		struct enetc_tx_swbd *tx_swbd = &tx_ring->tx_swbd[i];



		enetc_free_tx_frame(tx_ring, tx_swbd);

		if (i == 0)

			i = tx_ring->bd_count;

		i--;

	}

}



static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)

{

	bool do_vlan, do_onestep_tstamp = false, do_twostep_tstamp = false;
@@ -328,13 +346,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb) 
dma_err:

	dev_err(tx_ring->dev, "DMA map error");



	do {

		tx_swbd = &tx_ring->tx_swbd[i];

		enetc_free_tx_frame(tx_ring, tx_swbd);

		if (i == 0)

			i = tx_ring->bd_count;

		i--;

	} while (count--);

	enetc_unwind_tx_frame(tx_ring, count, i);



	return 0;

}