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 --- net/ethtool/debug.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 net/ethtool/debug.c (limited to 'net/ethtool/debug.c') diff --git a/net/ethtool/debug.c b/net/ethtool/debug.c new file mode 100644 index 000000000..6043916b4 --- /dev/null +++ b/net/ethtool/debug.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "bitset.h" +#include "common.h" +#include "netlink.h" + +struct debug_req_info { + struct ethnl_req_info base; +}; + +struct debug_reply_data { + struct ethnl_reply_data base; + u32 msg_mask; +}; + +#define DEBUG_REPDATA(__reply_base) \ + container_of(__reply_base, struct debug_reply_data, base) + +const struct nla_policy ethnl_debug_get_policy[] = { + [ETHTOOL_A_DEBUG_HEADER] = + NLA_POLICY_NESTED(ethnl_header_policy), +}; + +static int debug_prepare_data(const struct ethnl_req_info *req_base, + struct ethnl_reply_data *reply_base, + const struct genl_info *info) +{ + struct debug_reply_data *data = DEBUG_REPDATA(reply_base); + struct net_device *dev = reply_base->dev; + int ret; + + if (!dev->ethtool_ops->get_msglevel) + return -EOPNOTSUPP; + + ret = ethnl_ops_begin(dev); + if (ret < 0) + return ret; + data->msg_mask = dev->ethtool_ops->get_msglevel(dev); + ethnl_ops_complete(dev); + + return 0; +} + +static int debug_reply_size(const struct ethnl_req_info *req_base, + const struct ethnl_reply_data *reply_base) +{ + const struct debug_reply_data *data = DEBUG_REPDATA(reply_base); + bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS; + + return ethnl_bitset32_size(&data->msg_mask, NULL, NETIF_MSG_CLASS_COUNT, + netif_msg_class_names, compact); +} + +static int debug_fill_reply(struct sk_buff *skb, + const struct ethnl_req_info *req_base, + const struct ethnl_reply_data *reply_base) +{ + const struct debug_reply_data *data = DEBUG_REPDATA(reply_base); + bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS; + + return ethnl_put_bitset32(skb, ETHTOOL_A_DEBUG_MSGMASK, &data->msg_mask, + NULL, NETIF_MSG_CLASS_COUNT, + netif_msg_class_names, compact); +} + +/* DEBUG_SET */ + +const struct nla_policy ethnl_debug_set_policy[] = { + [ETHTOOL_A_DEBUG_HEADER] = + NLA_POLICY_NESTED(ethnl_header_policy), + [ETHTOOL_A_DEBUG_MSGMASK] = { .type = NLA_NESTED }, +}; + +static int +ethnl_set_debug_validate(struct ethnl_req_info *req_info, + struct genl_info *info) +{ + const struct ethtool_ops *ops = req_info->dev->ethtool_ops; + + return ops->get_msglevel && ops->set_msglevel ? 1 : -EOPNOTSUPP; +} + +static int +ethnl_set_debug(struct ethnl_req_info *req_info, struct genl_info *info) +{ + struct net_device *dev = req_info->dev; + struct nlattr **tb = info->attrs; + bool mod = false; + u32 msg_mask; + int ret; + + msg_mask = dev->ethtool_ops->get_msglevel(dev); + ret = ethnl_update_bitset32(&msg_mask, NETIF_MSG_CLASS_COUNT, + tb[ETHTOOL_A_DEBUG_MSGMASK], + netif_msg_class_names, info->extack, &mod); + if (ret < 0 || !mod) + return ret; + + dev->ethtool_ops->set_msglevel(dev, msg_mask); + return 1; +} + +const struct ethnl_request_ops ethnl_debug_request_ops = { + .request_cmd = ETHTOOL_MSG_DEBUG_GET, + .reply_cmd = ETHTOOL_MSG_DEBUG_GET_REPLY, + .hdr_attr = ETHTOOL_A_DEBUG_HEADER, + .req_info_size = sizeof(struct debug_req_info), + .reply_data_size = sizeof(struct debug_reply_data), + + .prepare_data = debug_prepare_data, + .reply_size = debug_reply_size, + .fill_reply = debug_fill_reply, + + .set_validate = ethnl_set_debug_validate, + .set = ethnl_set_debug, + .set_ntf_cmd = ETHTOOL_MSG_DEBUG_NTF, +}; -- cgit v1.3.1