CVE-2026-98025

NameCVE-2026-98025
DescriptionIn the Linux kernel, the following vulnerability has been resolved: net: usb: cx82310_eth: drop URB after 0xffff reboot sentinel to prevent partial_data heap overflow The 0xffff length sentinel detects a router reboot and schedules re-enabling of ethernet mode, but then falls through to the rest of the loop body. The next check is } else if (len > CX82310_MTU) { which is the else of the just-matched if -- it never fires for len == 0xffff. The MTU bound that normally caps the incomplete-packet save path is silently bypassed. With 0xffff > skb->len always true (rx_urb_size is 4096), the incomplete-packet branch saves dev->partial_len = skb->len bytes into dev->partial_data. partial_data is kmalloc(hard_mtu) = kmalloc(CX82310_MTU + 2) = 1516 bytes, but skb->len after the 2-byte header pull can be up to 4094. A device that sends a 4096-byte URB starting with [0xff 0xff] therefore copies 4094 device-provided bytes into a buffer allocated for 1516 bytes, exceeding its requested size by 2578 bytes. The next URB then reads dev->partial_len (4094) back from the same 1516-byte buffer and dev->partial_rem (65535 - 4094 = 61441) from the new URB's ~4KB skb, both well past their allocations, and delivers the spliced result as a 64KB "frame" to the network stack. Bail out of rx_fixup after scheduling the re-enable work; the remainder of a reboot-marker URB is not meaningful packet data. This restores the invariant that partial_len < CX82310_MTU + 2 on the save path, since every other route there has already passed the MTU check.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-4817-1, DSA-6528-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bookworm6.1.176-1vulnerable
bookworm (security)6.1.187-1vulnerable
trixie6.12.107-1vulnerable
trixie (security)6.12.111-1fixed
forky7.2.9-1fixed
sid7.2.10-1fixed
linux-6.12 (PTS)bookworm (security)6.12.111-1~deb12u1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcetrixie6.12.111-1DSA-6528-1
linuxsource(unstable)7.2.7-1
linux-6.12sourcebookworm6.12.111-1~deb12u1DLA-4817-1

Notes

https://git.kernel.org/linus/5d50e90add8b4a978395e893e81954d19d58a7c5 (7.3-rc3)

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