Linux: Out-of-bounds Read
CVE-2025-38224 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions d8a054b6e6824a8b52c3977ebd38c9583a63efac, a6550c9aa11e2f57f9cdaa6249cdd44d446be874, 54ec8b08216f3be2cc98b33633d3c8ea79749895 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d8a054b6e6824a8b52c3977ebd38c9583a63efac or a6550c9aa11e2f57f9cdaa6249cdd44d446be874 or 54ec8b08216f3be2cc98b33633d3c8ea79749895 or 6.12.35, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.35 or 6.15 or 6.15.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 352fbde14177d608a54120b6ff559ce5b3cf6238 up to, but not including, d8a054b6e6824a8b52c3977ebd38c9583a63efac; 8256e0ca601051933e9395746817f3801fa9a6bf up to, but not including, a6550c9aa11e2f57f9cdaa6249cdd44d446be874; 8256e0ca601051933e9395746817f3801fa9a6bf up to, but not including, 54ec8b08216f3be2cc98b33633d3c8ea79749895; f14512f3ee09cda986191c8dd7f54972afa2c763; 6.12.31 up to, but not including, 6.12.35; 6.14.9 up to, but not including, 6.15; 6.15 | d8a054b6e6824a8b52c3977ebd38c9583a63efac, a6550c9aa11e2f57f9cdaa6249cdd44d446be874, 54ec8b08216f3be2cc98b33633d3c8ea79749895, 6.12.35, 6.15 |
| Linux | Linux Kernel | 6.12.31 up to, but not including, 6.12.35; 6.14.9 up to, but not including, 6.15; 6.15.1 up to, but not including, 6.15.4; 6.15 | 6.12.35, 6.15, 6.15.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 8.4 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
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