Bug 2439924 (CVE-2026-23172)
| Summary: | CVE-2026-23172 kernel: Linux kernel t7xx WWAN driver: Denial of Service via buffer overflow | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | rhel-process-autobot, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's t7xx WWAN driver. A malicious, buggy, or compromised modem firmware can exploit this by sending packets with excessive fragments. This leads to a buffer overflow in the `skb_shinfo(skb)->frags[]` array, corrupting adjacent memory. This can result in kernel crashes or other undefined behavior, effectively causing a Denial of Service (DoS).
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
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Upstream advisory: https://lore.kernel.org/linux-cve-announce/2026021421-CVE-2026-23172-acf0@gregkh/T This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2026:68507 https://access.redhat.com/errata/RHSA-2026:68507 This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2026:68570 https://access.redhat.com/errata/RHSA-2026:68570 |
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.