From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- drivers/net/netdevsim/tc.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 drivers/net/netdevsim/tc.c (limited to 'drivers/net/netdevsim/tc.c') diff --git a/drivers/net/netdevsim/tc.c b/drivers/net/netdevsim/tc.c new file mode 100644 index 000000000..a415e02a6 --- /dev/null +++ b/drivers/net/netdevsim/tc.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include + +#include "netdevsim.h" + +static int +nsim_setup_tc_block_cb(enum tc_setup_type type, void *type_data, void *cb_priv) +{ + struct flow_cls_common_offload *common = type_data; + int err = 0; + + switch (type) { + case TC_SETUP_CLSBPF: + err = nsim_bpf_setup_tc_block_cb(type, type_data, cb_priv); + break; + case TC_SETUP_CLSFLOWER: + break; + default: + NSIM_EA(common->extack, "offload type not supported"); + err = -EOPNOTSUPP; + break; + } + + return err; +} + +static void nsim_taprio_stats(struct tc_taprio_qopt_stats *stats) +{ + stats->window_drops = 0; + stats->tx_overruns = 0; +} + +static int nsim_setup_tc_taprio(struct net_device *dev, + struct tc_taprio_qopt_offload *offload) +{ + int err = 0; + + switch (offload->cmd) { + case TAPRIO_CMD_REPLACE: + case TAPRIO_CMD_DESTROY: + break; + case TAPRIO_CMD_STATS: + nsim_taprio_stats(&offload->stats); + break; + default: + err = -EOPNOTSUPP; + } + + return err; +} + +static int nsim_setup_tc_ets(struct net_device *dev, + struct tc_ets_qopt_offload *offload) +{ + int err = 0; + + switch (offload->command) { + case TC_ETS_REPLACE: + case TC_ETS_DESTROY: + break; + case TC_ETS_STATS: + _bstats_update(offload->stats.bstats, 0, 0); + break; + default: + err = -EOPNOTSUPP; + } + + return err; +} + +static LIST_HEAD(nsim_block_cb_list); + +int +nsim_setup_tc(struct net_device *dev, enum tc_setup_type type, void *type_data) +{ + struct netdevsim *ns = netdev_priv(dev); + + switch (type) { + case TC_SETUP_QDISC_TAPRIO: + return nsim_setup_tc_taprio(dev, type_data); + case TC_SETUP_QDISC_ETS: + return nsim_setup_tc_ets(dev, type_data); + case TC_SETUP_BLOCK: + return flow_block_cb_setup_simple(type_data, + &nsim_block_cb_list, + nsim_setup_tc_block_cb, + ns, ns, true); + case TC_SETUP_FT: + return 0; + default: + return -EOPNOTSUPP; + } +} +ALLOW_ERROR_INJECTION(nsim_setup_tc, ERRNO); -- cgit v1.3.1