Bug 2546543 (CVE-2026-98238) - CVE-2026-98238 kernel: net: wwan: t7xx: validate the netif index in t7xx_ccmni_recv_skb()
Summary: CVE-2026-98238 kernel: net: wwan: t7xx: validate the netif index in t7xx_ccmn...
Keywords:
Status: NEW
Alias: CVE-2026-98238
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-06 09:41 UTC by OSIDB Bzimport
Modified: 2026-10-09 11:37 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
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Description OSIDB Bzimport 2026-10-06 09:41:55 UTC
In the Linux kernel, the following vulnerability has been resolved:

net: wwan: t7xx: validate the netif index in t7xx_ccmni_recv_skb()

The netif index carried in the DPMAIF PIT header is five bits wide,
but ccmni_inst[] only has room for NIC_DEV_MAX (21) entries.
t7xx_ccmni_recv_skb() indexes the array without a bounds check, so
indexes 21 to 31 read past it.  The out-of-bounds value lands in the
callback table that follows the array, which is never NULL, so the
existing !ccmni check does not catch it and the driver dereferences
whatever sits there as a struct t7xx_ccmni.

Drop the skb when the index is out of range.


Verified in a QEMU guest with a fault injector setting the netif
index to 25: the unpatched driver reads a value past ccmni_inst[],
which lands in the callback table, and dereferences it far enough to
queue the skb.  With this check the packet is dropped.  Well-formed
traffic on index 0 is unaffected.

Changes in v2: none.


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