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 --- include/net/hotdata.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 include/net/hotdata.h (limited to 'include/net/hotdata.h') diff --git a/include/net/hotdata.h b/include/net/hotdata.h new file mode 100644 index 000000000..62534d1f3 --- /dev/null +++ b/include/net/hotdata.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _NET_HOTDATA_H +#define _NET_HOTDATA_H + +#include +#include +#include +#include +#ifdef CONFIG_RPS +#include +#endif + +struct skb_defer_node { + struct llist_head defer_list; + atomic_long_t defer_count; +} ____cacheline_aligned_in_smp; + +/* Read mostly data used in network fast paths. */ +struct net_hotdata { +#if IS_ENABLED(CONFIG_INET) + struct packet_offload ip_packet_offload; + struct net_offload tcpv4_offload; + struct net_protocol tcp_protocol; + struct net_offload udpv4_offload; + struct net_protocol udp_protocol; + struct packet_offload ipv6_packet_offload; + struct net_offload tcpv6_offload; +#if IS_ENABLED(CONFIG_IPV6) + struct inet6_protocol tcpv6_protocol; + struct inet6_protocol udpv6_protocol; +#endif + struct net_offload udpv6_offload; +#endif + struct list_head offload_base; + struct kmem_cache *skbuff_cache; + struct kmem_cache *skbuff_fclone_cache; + struct kmem_cache *skb_small_head_cache; +#ifdef CONFIG_RPS + rps_tag_ptr rps_sock_flow_table; + u32 rps_cpu_mask; +#endif + struct skb_defer_node __percpu *skb_defer_nodes; + int gro_normal_batch; + int netdev_budget; + int netdev_budget_usecs; + int tstamp_prequeue; + int max_backlog; + int qdisc_max_burst; + int dev_tx_weight; + int dev_rx_weight; + int sysctl_max_skb_frags; + int sysctl_skb_defer_max; + int sysctl_mem_pcpu_rsv; +}; + +#define inet_ehash_secret net_hotdata.tcp_protocol.secret +#define udp_ehash_secret net_hotdata.udp_protocol.secret +#define inet6_ehash_secret net_hotdata.tcpv6_protocol.secret +#define tcp_ipv6_hash_secret net_hotdata.tcpv6_offload.secret +#define udp6_ehash_secret net_hotdata.udpv6_protocol.secret +#define udp_ipv6_hash_secret net_hotdata.udpv6_offload.secret + +extern struct net_hotdata net_hotdata; + +#endif /* _NET_HOTDATA_H */ -- cgit v1.3.1