lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [day] [month] [year] [list]
Message-ID: <2024051949-CVE-2024-35892-0f0c@gregkh>
Date: Sun, 19 May 2024 10:35:06 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: CVE-2024-35892: net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()

qdisc_tree_reduce_backlog() is called with the qdisc lock held,
not RTNL.

We must use qdisc_lookup_rcu() instead of qdisc_lookup()

syzbot reported:

WARNING: suspicious RCU usage
6.1.74-syzkaller #0 Not tainted
-----------------------------
net/sched/sch_api.c:305 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by udevd/1142:
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: net_tx_action+0x64a/0x970 net/core/dev.c:5282
  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: net_tx_action+0x754/0x970 net/core/dev.c:5297
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: qdisc_tree_reduce_backlog+0x84/0x580 net/sched/sch_api.c:792

stack backtrace:
CPU: 1 PID: 1142 Comm: udevd Not tainted 6.1.74-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
  [<ffffffff85b85f14>] __dump_stack lib/dump_stack.c:88 [inline]
  [<ffffffff85b85f14>] dump_stack_lvl+0x1b1/0x28f lib/dump_stack.c:106
  [<ffffffff85b86007>] dump_stack+0x15/0x1e lib/dump_stack.c:113
  [<ffffffff81802299>] lockdep_rcu_suspicious+0x1b9/0x260 kernel/locking/lockdep.c:6592
  [<ffffffff84f0054c>] qdisc_lookup+0xac/0x6f0 net/sched/sch_api.c:305
  [<ffffffff84f037c3>] qdisc_tree_reduce_backlog+0x243/0x580 net/sched/sch_api.c:811
  [<ffffffff84f5b78c>] pfifo_tail_enqueue+0x32c/0x4b0 net/sched/sch_fifo.c:51
  [<ffffffff84fbcf63>] qdisc_enqueue include/net/sch_generic.h:833 [inline]
  [<ffffffff84fbcf63>] netem_dequeue+0xeb3/0x15d0 net/sched/sch_netem.c:723
  [<ffffffff84eecab9>] dequeue_skb net/sched/sch_generic.c:292 [inline]
  [<ffffffff84eecab9>] qdisc_restart net/sched/sch_generic.c:397 [inline]
  [<ffffffff84eecab9>] __qdisc_run+0x249/0x1e60 net/sched/sch_generic.c:415
  [<ffffffff84d7aa96>] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125
  [<ffffffff84d85d29>] net_tx_action+0x7c9/0x970 net/core/dev.c:5313
  [<ffffffff85e002bd>] __do_softirq+0x2bd/0x9bd kernel/softirq.c:616
  [<ffffffff81568bca>] invoke_softirq kernel/softirq.c:447 [inline]
  [<ffffffff81568bca>] __irq_exit_rcu+0xca/0x230 kernel/softirq.c:700
  [<ffffffff81568ae9>] irq_exit_rcu+0x9/0x20 kernel/softirq.c:712
  [<ffffffff85b89f52>] sysvec_apic_timer_interrupt+0x42/0x90 arch/x86/kernel/apic/apic.c:1107
  [<ffffffff85c00ccb>] asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:656

The Linux kernel CVE team has assigned CVE-2024-35892 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.1.34 with commit 9d9a38b5639f and fixed in 6.1.85 with commit b7d1ce2cc719
	Issue introduced in 6.4 with commit d636fc5dd692 and fixed in 6.6.26 with commit c040b99461a5
	Issue introduced in 6.4 with commit d636fc5dd692 and fixed in 6.8.5 with commit 07696415526b
	Issue introduced in 6.4 with commit d636fc5dd692 and fixed in 6.9 with commit 7eb322360b02
	Issue introduced in 6.3.8 with commit 3a4741bb13ca

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-35892
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	net/sched/sch_api.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/b7d1ce2cc7192e8a037faa3f5d3ba72c25976460
	https://git.kernel.org/stable/c/c040b99461a5bfc14c2d0cbb1780fcc3a4706c7e
	https://git.kernel.org/stable/c/07696415526bee0607e495017369c7303a4792e1
	https://git.kernel.org/stable/c/7eb322360b0266481e560d1807ee79e0cef5742b

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ