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/packet/internal.h | 159 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 net/packet/internal.h (limited to 'net/packet/internal.h') diff --git a/net/packet/internal.h b/net/packet/internal.h new file mode 100644 index 000000000..b76e645cd --- /dev/null +++ b/net/packet/internal.h @@ -0,0 +1,159 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PACKET_INTERNAL_H__ +#define __PACKET_INTERNAL_H__ + +#include + +struct packet_mclist { + struct packet_mclist *next; + int ifindex; + int count; + unsigned short type; + unsigned short alen; + unsigned char addr[MAX_ADDR_LEN]; + struct list_head remove_list; +}; + +/* kbdq - kernel block descriptor queue */ +struct tpacket_kbdq_core { + struct pgv *pkbdq; + unsigned int feature_req_word; + unsigned int hdrlen; + unsigned char reset_pending_on_curr_blk; + unsigned short kactive_blk_num; + unsigned short blk_sizeof_priv; + + unsigned short version; + + char *pkblk_start; + char *pkblk_end; + int kblk_size; + unsigned int max_frame_len; + unsigned int knum_blocks; + uint64_t knxt_seq_num; + char *prev; + char *nxt_offset; + + struct sk_buff *skb; + + rwlock_t blk_fill_in_prog_lock; + + /* Default is set to 8ms */ +#define DEFAULT_PRB_RETIRE_TOV (8) + + ktime_t interval_ktime; + + /* timer to retire an outstanding block */ + struct hrtimer retire_blk_timer; +}; + +struct pgv { + char *buffer; +}; + +struct packet_ring_buffer { + struct pgv *pg_vec; + + unsigned int head; + unsigned int frames_per_block; + unsigned int frame_size; + unsigned int frame_max; + + unsigned int pg_vec_order; + unsigned int pg_vec_pages; + unsigned int pg_vec_len; + + unsigned int __percpu *pending_refcnt; + + union { + unsigned long *rx_owner_map; + struct tpacket_kbdq_core prb_bdqc; + }; +}; + +extern struct mutex fanout_mutex; +#define PACKET_FANOUT_MAX (1 << 16) + +struct packet_fanout { + possible_net_t net; + unsigned int num_members; + u32 max_num_members; + u16 id; + u8 type; + u8 flags; + union { + atomic_t rr_cur; + struct bpf_prog __rcu *bpf_prog; + }; + struct list_head list; + spinlock_t lock; + refcount_t sk_ref; + struct packet_type prot_hook ____cacheline_aligned_in_smp; + struct sock __rcu *arr[] __counted_by(max_num_members); +}; + +struct packet_rollover { + int sock; + atomic_long_t num; + atomic_long_t num_huge; + atomic_long_t num_failed; +#define ROLLOVER_HLEN (L1_CACHE_BYTES / sizeof(u32)) + u32 history[ROLLOVER_HLEN] ____cacheline_aligned; +} ____cacheline_aligned_in_smp; + +struct packet_sock { + /* struct sock has to be the first member of packet_sock */ + struct sock sk; + struct packet_fanout *fanout; + union tpacket_stats_u stats; + struct packet_ring_buffer rx_ring; + struct packet_ring_buffer tx_ring; + int copy_thresh; + spinlock_t bind_lock; + struct mutex pg_vec_lock; + unsigned long flags; + int ifindex; /* bound device */ + u8 vnet_hdr_sz; + __be16 num; + struct packet_rollover *rollover; + struct packet_mclist *mclist; + atomic_long_t mapped; + enum tpacket_versions tp_version; + unsigned int tp_hdrlen; + unsigned int tp_reserve; + unsigned int tp_tstamp; + struct completion skb_completion; + struct net_device __rcu *cached_dev; + struct packet_type prot_hook ____cacheline_aligned_in_smp; + atomic_t tp_drops ____cacheline_aligned_in_smp; +}; + +#define pkt_sk(ptr) container_of_const(ptr, struct packet_sock, sk) + +enum packet_sock_flags { + PACKET_SOCK_ORIGDEV, + PACKET_SOCK_AUXDATA, + PACKET_SOCK_TX_HAS_OFF, + PACKET_SOCK_TP_LOSS, + PACKET_SOCK_RUNNING, + PACKET_SOCK_PRESSURE, + PACKET_SOCK_QDISC_BYPASS, +}; + +static inline void packet_sock_flag_set(struct packet_sock *po, + enum packet_sock_flags flag, + bool val) +{ + if (val) + set_bit(flag, &po->flags); + else + clear_bit(flag, &po->flags); +} + +static inline bool packet_sock_flag(const struct packet_sock *po, + enum packet_sock_flags flag) +{ + return test_bit(flag, &po->flags); +} + +#endif -- cgit v1.3.1