linux-cve-announce - CVE-2023-53094: tty: serial: fsl_lpuart: fix race on RX DMA shutdown

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: <2025050221-CVE-2023-53094-a015@gregkh>
Date: Fri,  2 May 2025 17:55:59 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2023-53094: tty: serial: fsl_lpuart: fix race on RX DMA shutdown

From: Greg Kroah-Hartman <gregkh@...nel.org>

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

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

tty: serial: fsl_lpuart: fix race on RX DMA shutdown

>>From time to time DMA completion can come in the middle of DMA shutdown:

<process ctx>:				<IRQ>:
lpuart32_shutdown()
  lpuart_dma_shutdown()
    del_timer_sync()
					lpuart_dma_rx_complete()
					  lpuart_copy_rx_to_tty()
					    mod_timer()
    lpuart_dma_rx_free()

When the timer fires a bit later, sport->dma_rx_desc is NULL:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
pc : lpuart_copy_rx_to_tty+0xcc/0x5bc
lr : lpuart_timer_func+0x1c/0x2c
Call trace:
 lpuart_copy_rx_to_tty
 lpuart_timer_func
 call_timer_fn
 __run_timers.part.0
 run_timer_softirq
 __do_softirq
 __irq_exit_rcu
 irq_exit
 handle_domain_irq
 gic_handle_irq
 call_on_irq_stack
 do_interrupt_handler
 ...

To fix this fold del_timer_sync() into lpuart_dma_rx_free() after
dmaengine_terminate_sync() to make sure timer will not be re-started in
lpuart_copy_rx_to_tty() <= lpuart_dma_rx_complete().

The Linux kernel CVE team has assigned CVE-2023-53094 to this issue.


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

	Issue introduced in 4.0 with commit 4a8588a1cf867333187d9ff071e6fbdab587d194 and fixed in 5.10.177 with commit 19a98d56dfedafb25652bdb9cd48a4e73ceba702
	Issue introduced in 4.0 with commit 4a8588a1cf867333187d9ff071e6fbdab587d194 and fixed in 5.15.105 with commit 90530e7214c8a04dcdde57502d93fa96af288c38
	Issue introduced in 4.0 with commit 4a8588a1cf867333187d9ff071e6fbdab587d194 and fixed in 6.1.23 with commit 954fc9931f0aabf272b5674cf468affdd88d3a36
	Issue introduced in 4.0 with commit 4a8588a1cf867333187d9ff071e6fbdab587d194 and fixed in 6.2.8 with commit 2a36b444cace9580380467fd1183bb5e85bcc80a
	Issue introduced in 4.0 with commit 4a8588a1cf867333187d9ff071e6fbdab587d194 and fixed in 6.3 with commit 1be6f2b15f902c02e055ae0b419ca789200473c9
	Issue introduced in 3.18.9 with commit 5716a781032693d0f812ed06528d98195e9df028
	Issue introduced in 3.19.1 with commit 0d5cb6e8b4b62d8efd1a470615894276341d6db9

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-2023-53094
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:
	drivers/tty/serial/fsl_lpuart.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/19a98d56dfedafb25652bdb9cd48a4e73ceba702
	https://git.kernel.org/stable/c/90530e7214c8a04dcdde57502d93fa96af288c38
	https://git.kernel.org/stable/c/954fc9931f0aabf272b5674cf468affdd88d3a36
	https://git.kernel.org/stable/c/2a36b444cace9580380467fd1183bb5e85bcc80a
	https://git.kernel.org/stable/c/1be6f2b15f902c02e055ae0b419ca789200473c9