{"id":"CVE-2026-98025","published":"2026-09-25T11:17:31.110","lastModified":"2026-09-25T11:17:31.110","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: cx82310_eth: drop URB after 0xffff reboot sentinel to prevent partial_data heap overflow\n\nThe 0xffff length sentinel detects a router reboot and schedules\nre-enabling of ethernet mode, but then falls through to the rest\nof the loop body.  The next check is\n\n\t} else if (len > CX82310_MTU) {\n\nwhich is the else of the just-matched if -- it never fires for\nlen == 0xffff.  The MTU bound that normally caps the\nincomplete-packet save path is silently bypassed.\n\nWith 0xffff > skb->len always true (rx_urb_size is 4096), the\nincomplete-packet branch saves dev->partial_len = skb->len bytes\ninto dev->partial_data.  partial_data is kmalloc(hard_mtu) =\nkmalloc(CX82310_MTU + 2) = 1516 bytes, but skb->len after the\n2-byte header pull can be up to 4094.  A device that sends a\n4096-byte URB starting with [0xff 0xff] therefore copies 4094\ndevice-provided bytes into a buffer allocated for 1516 bytes,\nexceeding its requested size by 2578 bytes.\n\nThe next URB then reads dev->partial_len (4094) back from the same\n1516-byte buffer and dev->partial_rem (65535 - 4094 = 61441) from\nthe new URB's ~4KB skb, both well past their allocations, and\ndelivers the spliced result as a 64KB \"frame\" to the network\nstack.\n\nBail out of rx_fixup after scheduling the re-enable work; the\nremainder of a reboot-marker URB is not meaningful packet data.\nThis restores the invariant that partial_len < CX82310_MTU + 2 on\nthe save path, since every other route there has already passed\nthe MTU check.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/237c9ae7145772af147e4665f158938350fa5658","tags":[]},{"url":"https://git.kernel.org/stable/c/3bd689409bb1c93bdc6dd8ec6cbf5161bc4f0287","tags":[]},{"url":"https://git.kernel.org/stable/c/5d50e90add8b4a978395e893e81954d19d58a7c5","tags":[]},{"url":"https://git.kernel.org/stable/c/659654654eb140851467af41d610473c100c7975","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}