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/rxrpc/sysctl.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 net/rxrpc/sysctl.c (limited to 'net/rxrpc/sysctl.c') diff --git a/net/rxrpc/sysctl.c b/net/rxrpc/sysctl.c new file mode 100644 index 000000000..46a20cf4c --- /dev/null +++ b/net/rxrpc/sysctl.c @@ -0,0 +1,147 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* sysctls for configuring RxRPC operating parameters + * + * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include "ar-internal.h" + +static struct ctl_table_header *rxrpc_sysctl_reg_table; +static const unsigned int rxrpc_rx_mtu_min = 500; +static const unsigned int rxrpc_jumbo_max = RXRPC_MAX_NR_JUMBO; +static const unsigned int four = 4; +static const unsigned int max_backlog = RXRPC_BACKLOG_MAX - 1; +static const unsigned int n_65535 = 65535; +static const unsigned int n_max_acks = 255; +static const unsigned long one_ms = 1; +static const unsigned long max_ms = 1000; +static const unsigned long one_jiffy = 1; +static const unsigned long max_jiffies = MAX_JIFFY_OFFSET; +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY +static const unsigned long max_500 = 500; +#endif + +/* + * RxRPC operating parameters. + * + * See Documentation/networking/rxrpc.rst and the variable definitions for more + * information on the individual parameters. + */ +static struct ctl_table rxrpc_sysctl_table[] = { + /* Values measured in milliseconds */ + { + .procname = "soft_ack_delay", + .data = &rxrpc_soft_ack_delay, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + .extra1 = (void *)&one_ms, + .extra2 = (void *)&max_ms, + }, + { + .procname = "idle_ack_delay", + .data = &rxrpc_idle_ack_delay, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + .extra1 = (void *)&one_ms, + .extra2 = (void *)&max_ms, + }, + { + .procname = "idle_conn_expiry", + .data = &rxrpc_conn_idle_client_expiry, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_ms_jiffies_minmax, + .extra1 = (void *)&one_jiffy, + .extra2 = (void *)&max_jiffies, + }, + { + .procname = "idle_conn_fast_expiry", + .data = &rxrpc_conn_idle_client_fast_expiry, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_ms_jiffies_minmax, + .extra1 = (void *)&one_jiffy, + .extra2 = (void *)&max_jiffies, + }, + + /* Values used in milliseconds */ +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY + { + .procname = "inject_rx_delay", + .data = &rxrpc_inject_rx_delay, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + .extra1 = (void *)SYSCTL_LONG_ZERO, + .extra2 = (void *)&max_500, + }, +#endif + + /* Non-time values */ + { + .procname = "reap_client_conns", + .data = &rxrpc_reap_client_connections, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)SYSCTL_ONE, + .extra2 = (void *)&n_65535, + }, + { + .procname = "max_backlog", + .data = &rxrpc_max_backlog, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&four, + .extra2 = (void *)&max_backlog, + }, + { + .procname = "rx_window_size", + .data = &rxrpc_rx_window_size, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)SYSCTL_ONE, + .extra2 = (void *)&n_max_acks, + }, + { + .procname = "rx_mtu", + .data = &rxrpc_rx_mtu, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&rxrpc_rx_mtu_min, + .extra2 = (void *)&n_65535, + }, + { + .procname = "rx_jumbo_max", + .data = &rxrpc_rx_jumbo_max, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)SYSCTL_ONE, + .extra2 = (void *)&rxrpc_jumbo_max, + }, +}; + +int __init rxrpc_sysctl_init(void) +{ + rxrpc_sysctl_reg_table = register_net_sysctl(&init_net, "net/rxrpc", + rxrpc_sysctl_table); + if (!rxrpc_sysctl_reg_table) + return -ENOMEM; + return 0; +} + +void rxrpc_sysctl_exit(void) +{ + if (rxrpc_sysctl_reg_table) + unregister_net_sysctl_table(rxrpc_sysctl_reg_table); +} -- cgit v1.3.1