PT-2026-65215 · Linux · Linux
CVE-2026-64540
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Published
2026-07-27
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Updated
2026-07-27
None
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In the Linux kernel, the following vulnerability has been resolved:
usbnet: gl620a: fix out-of-bounds read in genelink rx fixup()
genelink rx fixup() splits an aggregated RX frame into its individual
packets, using a per-packet length taken from device-supplied data. That
length is only bounded by GL MAX PACKET LEN (1514); it is never compared
against how many bytes were actually received.
A malicious GeneLink (GL620A) device can therefore send a short URB whose
header claims packet count > 1 and a first packet of up to 1514 bytes.
skb put data(gl skb, packet->packet data, size);then copies past the end of the receive buffer and hands the adjacent slab
contents up the network stack, an out-of-bounds read that leaks kernel heap.
No privilege is required: the path runs in the usbnet RX softirq as soon as
the interface is up.
BUG: KASAN: slab-out-of-bounds in genelink rx fixup (drivers/net/usb/gl620a.c:112)
Read of size 1514 at addr ffff888011309708 by task ksoftirqd/0/14
Call Trace:
...
asan memcpy (mm/kasan/shadow.c:105)
genelink rx fixup (include/linux/skbuff.h:2814 drivers/net/usb/gl620a.c:112)
usbnet bh (drivers/net/usb/usbnet.c:572 drivers/net/usb/usbnet.c:1589)
process one work (kernel/workqueue.c:3322)
bh worker (kernel/workqueue.c:3405)
tasklet action (kernel/softirq.c:965)
handle softirqs (kernel/softirq.c:622)
run ksoftirqd (kernel/softirq.c:1076)
...
skb pull() already verifies that the requested length fits the buffer and
returns NULL otherwise. Move it ahead of the copy and check its result, so
a packet that overruns the received data is rejected before it is read.
Well-formed frames, whose packets are fully present, are unaffected.
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Related Identifiers
Affected Products
Linux