From: Wei Fang Date: Wed, 24 Jun 2026 07:27:26 +0000 (+0800) Subject: net: enetc: fix potential divide-by-zero when num_vsi is zero X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=5da65537792b68b6052ffcab65e04c27aea6dfe4;p=thirdparty%2Fkernel%2Fstable.git net: enetc: fix potential divide-by-zero when num_vsi is zero For i.MX94 series, all the standalone ENETCs do not support SR-IOV, so pf->caps.num_vsi is zero. This leads to a divide-by-zero in enetc4_default_rings_allocation() when distributing rings among PF and VFs. Division by zero is undefined behavior in C. On ARM64, the UDIV/SDIV instructions silently return zero rather than raising an exception, so the issue does not cause a visible crash. However, relying on this behavior is incorrect and poses a cross-platform compatibility risk. Add an explicit check for num_vsi == 0 and return early after the PF's rings have been configured. Fixes: 2d673b0e2f8d ("net: enetc: add standalone ENETC support for i.MX94") Signed-off-by: Wei Fang Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20260624072726.1238903-1-wei.fang@oss.nxp.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/freescale/enetc/enetc4_pf.c b/drivers/net/ethernet/freescale/enetc/enetc4_pf.c index 4e771f852358..437a15bbb47b 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc4_pf.c +++ b/drivers/net/ethernet/freescale/enetc/enetc4_pf.c @@ -322,6 +322,9 @@ static void enetc4_default_rings_allocation(struct enetc_pf *pf) val = enetc4_psicfgr0_val_construct(false, num_tx_bdr, num_rx_bdr); enetc_port_wr(hw, ENETC4_PSICFGR0(0), val); + if (!pf->caps.num_vsi) + return; + num_rx_bdr = pf->caps.num_rx_bdr - num_rx_bdr; rx_rem = num_rx_bdr % pf->caps.num_vsi; num_rx_bdr = num_rx_bdr / pf->caps.num_vsi;