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Ziyang Xuan aa95efa187 net: qrtr: Fix a refcount bug in qrtr_recvmsg()
[ Upstream commit 44d8073200 ]

Syzbot reported a bug as following:

refcount_t: addition on 0; use-after-free.
...
RIP: 0010:refcount_warn_saturate+0x17c/0x1f0 lib/refcount.c:25
...
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:199 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 kref_get include/linux/kref.h:45 [inline]
 qrtr_node_acquire net/qrtr/af_qrtr.c:202 [inline]
 qrtr_node_lookup net/qrtr/af_qrtr.c:398 [inline]
 qrtr_send_resume_tx net/qrtr/af_qrtr.c:1003 [inline]
 qrtr_recvmsg+0x85f/0x990 net/qrtr/af_qrtr.c:1070
 sock_recvmsg_nosec net/socket.c:1017 [inline]
 sock_recvmsg+0xe2/0x160 net/socket.c:1038
 qrtr_ns_worker+0x170/0x1700 net/qrtr/ns.c:688
 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
 worker_thread+0x669/0x1090 kernel/workqueue.c:2537

It occurs in the concurrent scenario of qrtr_recvmsg() and
qrtr_endpoint_unregister() as following:

	cpu0					cpu1
qrtr_recvmsg				qrtr_endpoint_unregister
qrtr_send_resume_tx			qrtr_node_release
qrtr_node_lookup			mutex_lock(&qrtr_node_lock)
spin_lock_irqsave(&qrtr_nodes_lock, )	refcount_dec_and_test(&node->ref) [node->ref == 0]
radix_tree_lookup [node != NULL]	__qrtr_node_release
qrtr_node_acquire			spin_lock_irqsave(&qrtr_nodes_lock, )
kref_get(&node->ref) [WARNING]		...
					mutex_unlock(&qrtr_node_lock)

Use qrtr_node_lock to protect qrtr_node_lookup() implementation, this
is actually improving the protection of node reference.

Fixes: 0a7e0d0ef0 ("net: qrtr: Migrate node lookup tree to spinlock")
Reported-by: syzbot+a7492efaa5d61b51db23@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=a7492efaa5d61b51db23
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-13 16:55:20 +02:00
Documentation dt-bindings: mtd: jedec,spi-nor: Document CPOL/CPHA support 2023-04-06 12:10:55 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
arch KVM: s390: pv: fix external interruption loop not always detected 2023-04-13 16:55:19 +02:00
block block: do not reverse request order when flushing plug list 2023-03-22 13:33:46 +01:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: rsa-pkcs1pad - Use akcipher_request_complete 2023-03-10 09:33:03 +01:00
drivers pwm: meson: Explicitly set .polarity in .get_state() 2023-04-13 16:55:19 +02:00
fs NFSv4: Fix hangs when recovering open state after a server reboot 2023-04-06 12:10:54 +02:00
include pwm: Make .get_state() callback return an error code 2023-04-13 16:55:18 +02:00
init gcc: disable -Warray-bounds for gcc-11 too 2023-01-14 10:33:43 +01:00
io_uring io_uring: fix poll/netmsg alloc caches 2023-04-06 12:10:52 +02:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel tracing: Fix wrong return in kprobe_event_gen_test.c 2023-04-06 12:10:41 +02:00
lib zstd: Fix definition of assert() 2023-04-06 12:10:38 +02:00
mm mm/ksm: fix race with VMA iteration and mm_struct teardown 2023-03-30 12:49:29 +02:00
net net: qrtr: Fix a refcount bug in qrtr_recvmsg() 2023-04-13 16:55:20 +02:00
rust rust: print: avoid evaluating arguments in `pr_*` macros in `unsafe` blocks 2023-02-06 08:06:34 +01:00
samples ftrace: Export ftrace_free_filter() to modules 2023-02-01 08:34:37 +01:00
scripts modpost: Fix processing of CRCs on 32-bit build machines 2023-04-06 12:10:53 +02:00
security keys: Do not cache key in task struct if key is requested from kernel thread 2023-03-30 12:49:07 +02:00
sound ASoC: codecs: lpass: fix the order or clks turn off during suspend 2023-04-13 16:55:19 +02:00
tools libbpf: Fix btf_dump's packed struct determination 2023-04-06 12:10:58 +02:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Register /dev/kvm as the _very_ last thing during initialization 2023-03-10 09:34:11 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
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.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
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COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
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Makefile Linux 6.1.23 2023-04-06 12:10:58 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.