Linux Kernel prior 6.12.35/6.15.4/6.16-rc1 can alloc_candev array index

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.34/6.15.3/f14512f3ee09cda986191c8dd7f54972afa2c763. It has been rated as problematic. The impacted element is the function alloc_candev of the component can. Performing a manipulation results in array index. This vulnerability is reported as CVE-2025-38224. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.12.34/6.15.3/f14512f3ee09cda986191c8dd7f54972afa2c763. This affects the function alloc_candev of the component can. The manipulation with an unknown input leads to a array index vulnerability. CWE is classifying the issue as CWE-129. The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: can: kvaser_pciefd: refine error prone echo_skb_max handling logic echo_skb_max should define the supported upper limit of echo_skb[] allocated inside the netdevice's priv. The corresponding size value provided by this driver to alloc_candev() is KVASER_PCIEFD_CAN_TX_MAX_COUNT which is 17. But later echo_skb_max is rounded up to the nearest power of two (for the max case, that would be 32) and the tx/ack indices calculated further during tx/rx may exceed the upper array boundary. Kasan reported this for the ack case inside kvaser_pciefd_handle_ack_packet(), though the xmit function has actually caught the same thing earlier. BUG: KASAN: slab-out-of-bounds in kvaser_pciefd_handle_ack_packet+0x2d7/0x92a drivers/net/can/kvaser_pciefd.c:1528 Read of size 8 at addr ffff888105e4f078 by task swapper/4/0 CPU: 4 UID: 0 PID: 0 Comm: swapper/4 Not tainted 6.15.0 #12 PREEMPT(voluntary) Call Trace: <IRQ> dump_stack_lvl lib/dump_stack.c:122 print_report mm/kasan/report.c:521 kasan_report mm/kasan/report.c:634 kvaser_pciefd_handle_ack_packet drivers/net/can/kvaser_pciefd.c:1528 kvaser_pciefd_read_packet drivers/net/can/kvaser_pciefd.c:1605 kvaser_pciefd_read_buffer drivers/net/can/kvaser_pciefd.c:1656 kvaser_pciefd_receive_irq drivers/net/can/kvaser_pciefd.c:1684 kvaser_pciefd_irq_handler drivers/net/can/kvaser_pciefd.c:1733 __handle_irq_event_percpu kernel/irq/handle.c:158 handle_irq_event kernel/irq/handle.c:210 handle_edge_irq kernel/irq/chip.c:833 __common_interrupt arch/x86/kernel/irq.c:296 common_interrupt arch/x86/kernel/irq.c:286 </IRQ> Tx max count definitely matters for kvaser_pciefd_tx_avail(), but for seq numbers' generation that's not the case - we're free to calculate them as would be more convenient, not taking tx max count into account. The only downside is that the size of echo_skb[] should correspond to the max seq number (not tx max count), so in some situations a bit more memory would be consumed than could be. Thus make the size of the underlying echo_skb[] sufficient for the rounded max tx value. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-38224 since 04/16/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 12/14/2025).

The vulnerability scanner Nessus provides a plugin with the ID 243387 (Linux Distros Unpatched Vulnerability : CVE-2025-38224), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.35, 6.15.4 or 6.16-rc1 eliminates this vulnerability. Applying the patch d8a054b6e6824a8b52c3977ebd38c9583a63efac/a6550c9aa11e2f57f9cdaa6249cdd44d446be874/54ec8b08216f3be2cc98b33633d3c8ea79749895 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 databases at Tenable (243387), EUVD (EUVD-2025-20032) and CERT Bund (WID-SEC-2025-1465). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IBM QRadar SIEM
• SUSE openSUSE
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• Dell NetWorker
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.15.0
• 6.15.1
• 6.15.2
• 6.15.3
• f14512f3ee09cda986191c8dd7f54972afa2c763

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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