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/phonet/sysctl.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 net/phonet/sysctl.c (limited to 'net/phonet/sysctl.c') diff --git a/net/phonet/sysctl.c b/net/phonet/sysctl.c new file mode 100644 index 000000000..463a74a27 --- /dev/null +++ b/net/phonet/sysctl.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * File: sysctl.c + * + * Phonet /proc/sys/net/phonet interface implementation + * + * Copyright (C) 2008 Nokia Corporation. + * + * Author: Rémi Denis-Courmont + */ + +#include +#include +#include +#include + +#include +#include +#include + +#define DYNAMIC_PORT_MIN 0x40 +#define DYNAMIC_PORT_MAX 0x7f + +static DEFINE_SEQLOCK(local_port_range_lock); +static int local_port_range_min[2] = {0, 0}; +static int local_port_range_max[2] = {1023, 1023}; +static int local_port_range[2] = {DYNAMIC_PORT_MIN, DYNAMIC_PORT_MAX}; +static struct ctl_table_header *phonet_table_hrd; + +static void set_local_port_range(int range[2]) +{ + write_seqlock(&local_port_range_lock); + local_port_range[0] = range[0]; + local_port_range[1] = range[1]; + write_sequnlock(&local_port_range_lock); +} + +void phonet_get_local_port_range(int *min, int *max) +{ + unsigned int seq; + + do { + seq = read_seqbegin(&local_port_range_lock); + if (min) + *min = local_port_range[0]; + if (max) + *max = local_port_range[1]; + } while (read_seqretry(&local_port_range_lock, seq)); +} + +static int proc_local_port_range(const struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + int ret; + int range[2] = {local_port_range[0], local_port_range[1]}; + struct ctl_table tmp = { + .data = &range, + .maxlen = sizeof(range), + .mode = table->mode, + .extra1 = &local_port_range_min, + .extra2 = &local_port_range_max, + }; + + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + + if (write && ret == 0) { + if (range[1] < range[0]) + ret = -EINVAL; + else + set_local_port_range(range); + } + + return ret; +} + +static struct ctl_table phonet_table[] = { + { + .procname = "local_port_range", + .data = &local_port_range, + .maxlen = sizeof(local_port_range), + .mode = 0644, + .proc_handler = proc_local_port_range, + }, +}; + +int __init phonet_sysctl_init(void) +{ + phonet_table_hrd = register_net_sysctl(&init_net, "net/phonet", phonet_table); + return phonet_table_hrd == NULL ? -ENOMEM : 0; +} + +void phonet_sysctl_exit(void) +{ + unregister_net_sysctl_table(phonet_table_hrd); +} -- cgit v1.3.1