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/netprio_cgroup.h | 54 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 include/net/netprio_cgroup.h (limited to 'include/net/netprio_cgroup.h') diff --git a/include/net/netprio_cgroup.h b/include/net/netprio_cgroup.h new file mode 100644 index 000000000..dec7522b6 --- /dev/null +++ b/include/net/netprio_cgroup.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * netprio_cgroup.h Control Group Priority set + * + * Authors: Neil Horman + */ + +#ifndef _NETPRIO_CGROUP_H +#define _NETPRIO_CGROUP_H + +#include +#include +#include + +#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO) +struct netprio_map { + struct rcu_head rcu; + u32 priomap_len; + u32 priomap[]; +}; + +static inline u32 task_netprioidx(struct task_struct *p) +{ + struct cgroup_subsys_state *css; + u32 idx; + + rcu_read_lock(); + css = task_css(p, net_prio_cgrp_id); + idx = css->id; + rcu_read_unlock(); + return idx; +} + +static inline void sock_update_netprioidx(struct sock_cgroup_data *skcd) +{ + if (in_interrupt()) + return; + + sock_cgroup_set_prioidx(skcd, task_netprioidx(current)); +} + +#else /* !CONFIG_CGROUP_NET_PRIO */ + +static inline u32 task_netprioidx(struct task_struct *p) +{ + return 0; +} + +static inline void sock_update_netprioidx(struct sock_cgroup_data *skcd) +{ +} + +#endif /* CONFIG_CGROUP_NET_PRIO */ +#endif /* _NET_CLS_CGROUP_H */ -- cgit v1.3.1