From: Junrui Luo Date: Wed, 28 Jan 2026 08:07:34 +0000 (+0800) Subject: dpaa2-switch: prevent ZERO_SIZE_PTR dereference when num_ifs is zero X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ed48a84a72fefb20a82dd90a7caa7807e90c6f66;p=thirdparty%2Fkernel%2Flinux.git dpaa2-switch: prevent ZERO_SIZE_PTR dereference when num_ifs is zero The driver allocates arrays for ports, FDBs, and filter blocks using kcalloc() with ethsw->sw_attr.num_ifs as the element count. When the device reports zero interfaces (either due to hardware configuration or firmware issues), kcalloc(0, ...) returns ZERO_SIZE_PTR (0x10) instead of NULL. Later in dpaa2_switch_probe(), the NAPI initialization unconditionally accesses ethsw->ports[0]->netdev, which attempts to dereference ZERO_SIZE_PTR (address 0x10), resulting in a kernel panic. Add a check to ensure num_ifs is greater than zero after retrieving device attributes. This prevents the zero-sized allocations and subsequent invalid pointer dereference. Reported-by: Yuhao Jiang Reported-by: Junrui Luo Fixes: 0b1b71370458 ("staging: dpaa2-switch: handle Rx path on control interface") Signed-off-by: Junrui Luo Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/SYBPR01MB7881BEABA8DA896947962470AF91A@SYBPR01MB7881.ausprd01.prod.outlook.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c index b1e1ad9e4b48..0ff234f6a3ed 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c @@ -3024,6 +3024,12 @@ static int dpaa2_switch_init(struct fsl_mc_device *sw_dev) goto err_close; } + if (!ethsw->sw_attr.num_ifs) { + dev_err(dev, "DPSW device has no interfaces\n"); + err = -ENODEV; + goto err_close; + } + err = dpsw_get_api_version(ethsw->mc_io, 0, ðsw->major, ðsw->minor);