Linux Kernel up to 5.10.176/5.15.104/6.1.22/6.2.7 tty lpuart32_shutdown null pointer dereference

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 5.10.176/5.15.104/6.1.22/6.2.7. Impacted is the function lpuart32_shutdown of the component tty. Such manipulation leads to null pointer dereference. This vulnerability is listed as CVE-2023-53094. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.10.176/5.15.104/6.1.22/6.2.7. It has been rated as critical. Affected by this issue is the function lpuart32_shutdown of the component tty. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

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 advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2023-53094 since 05/02/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 240793 (SUSE SLES12 Security Update : kernel (SUSE-SU-2025:01983-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.177, 5.15.105, 6.1.23 or 6.2.8 eliminates this vulnerability. Applying the patch 19a98d56dfedafb25652bdb9cd48a4e73ceba702/90530e7214c8a04dcdde57502d93fa96af288c38/954fc9931f0aabf272b5674cf468affdd88d3a36/2a36b444cace9580380467fd1183bb5e85bcc80a/1be6f2b15f902c02e055ae0b419ca789200473c9 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (240793). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.176
• 5.15.104
• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.2.0
• 6.2.1
• 6.2.2
• 6.2.3
• 6.2.4
• 6.2.5
• 6.2.6
• 6.2.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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