CVE-2026-64132
Gravedad CVSS v3.1:
CRÍTICA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
19/07/2026
Última modificación:
30/07/2026
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
ipv6: ioam: refresh hdr pointer before ioam6_event()<br />
<br />
Reported by Sashiko:<br />
<br />
In ipv6_hop_ioam(), the hdr pointer is initialized to point into the<br />
skb&#39;s linear data buffer. Later, the code calls skb_ensure_writable(),<br />
which might reallocate the buffer:<br />
<br />
if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len))<br />
goto drop;<br />
<br />
/* Trace pointer may have changed */<br />
trace = (struct ioam6_trace_hdr *)(skb_network_header(skb)<br />
+ optoff + sizeof(*hdr));<br />
<br />
ioam6_fill_trace_data(skb, ns, trace, true);<br />
<br />
ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev),<br />
GFP_ATOMIC, (void *)trace, hdr->opt_len - 2);<br />
<br />
If the skb is cloned or lacks sufficient linear headroom,<br />
skb_ensure_writable() will invoke pskb_expand_head(), which reallocates<br />
the skb&#39;s data buffer and frees the old one, invalidating pointers to<br />
it. While the code recalculates the trace pointer immediately after the<br />
call to skb_ensure_writable(), it fails to recalculate the hdr pointer.<br />
<br />
This patch fixes the above by recalculating the hdr pointer before<br />
passing hdr->opt_len to ioam6_event(), so that we avoid any UaF.
Impacto
Puntuación base 3.x
9.80
Gravedad 3.x
CRÍTICA



