CVE-2026-23172
Unknown Unknown - Not Provided
Buffer Overflow in Linux Kernel t7xx_dpmaif RX Path

Publication date: 2026-02-14

Last updated on: 2026-04-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net: wwan: t7xx: fix potential skb->frags overflow in RX path When receiving data in the DPMAIF RX path, the t7xx_dpmaif_set_frag_to_skb() function adds page fragments to an skb without checking if the number of fragments has exceeded MAX_SKB_FRAGS. This could lead to a buffer overflow in skb_shinfo(skb)->frags[] array, corrupting adjacent memory and potentially causing kernel crashes or other undefined behavior. This issue was identified through static code analysis by comparing with a similar vulnerability fixed in the mt76 driver commit b102f0c522cf ("mt76: fix array overflow on receiving too many fragments for a packet"). The vulnerability could be triggered if the modem firmware sends packets with excessive fragments. While under normal protocol conditions (MTU 3080 bytes, BAT buffer 3584 bytes), a single packet should not require additional fragments, the kernel should not blindly trust firmware behavior. Malicious, buggy, or compromised firmware could potentially craft packets with more fragments than the kernel expects. Fix this by adding a bounds check before calling skb_add_rx_frag() to ensure nr_frags does not exceed MAX_SKB_FRAGS. The check must be performed before unmapping to avoid a page leak and double DMA unmap during device teardown.
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Meta Information
Published
2026-02-14
Last Modified
2026-04-03
Generated
2026-05-07
AI Q&A
2026-02-14
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 11 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel From 6.2 (inc) to 6.6.123 (exc)
linux linux_kernel 6.19
linux linux_kernel From 6.7 (inc) to 6.12.69 (exc)
linux linux_kernel From 5.19 (inc) to 6.1.162 (exc)
linux linux_kernel 6.19
linux linux_kernel From 6.13 (inc) to 6.18.9 (exc)
Helpful Resources
Exploitability
CWE
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KEV
KEV Icon
CWE ID Description
CWE-401 The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's network driver for wwan (wireless wide area network) devices, specifically in the t7xx_dpmaif_set_frag_to_skb() function. When receiving data packets, this function adds page fragments to a socket buffer (skb) without verifying if the number of fragments exceeds the maximum allowed (MAX_SKB_FRAGS).

If the number of fragments exceeds this limit, it can cause a buffer overflow in the skb's fragments array, which may corrupt adjacent memory. This memory corruption can lead to kernel crashes or other unpredictable behavior.

The vulnerability could be triggered by malicious, buggy, or compromised modem firmware that sends packets with an excessive number of fragments, beyond what the kernel expects under normal conditions.

The fix involves adding a bounds check before adding fragments to ensure the number does not exceed MAX_SKB_FRAGS, preventing buffer overflow and related issues.


How can this vulnerability impact me? :

This vulnerability can impact you by causing kernel crashes or undefined behavior on systems running the affected Linux kernel with the vulnerable wwan driver.

If exploited, it could lead to system instability or denial of service due to memory corruption triggered by crafted packets with excessive fragments.

Since the issue arises from trusting potentially malicious modem firmware, compromised or buggy firmware could be used as an attack vector to exploit this vulnerability.


How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:

I don't know


How can this vulnerability be detected on my network or system? Can you suggest some commands?

I don't know


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, ensure that your Linux kernel is updated with the fix that adds a bounds check before calling skb_add_rx_frag() in the t7xx_dpmaif_set_frag_to_skb() function.

This fix prevents the skb->frags overflow by verifying that the number of fragments does not exceed MAX_SKB_FRAGS, protecting against buffer overflow and potential kernel crashes.

Since the vulnerability arises from potentially malicious or buggy modem firmware sending packets with excessive fragments, updating the kernel to include this fix is the immediate and effective mitigation step.


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