DEBIAN-CVE-2026-89783

In the Linux kernel, the following vulnerability has been resolved:  xfrm6: fix out-of-bounds write in xfrm6inputaddr() when secpath is full  The depth check in xfrm6inputaddr() is off by one:    if (1 + sp->len == XFRMMAXDEPTH)           goto drop;   ...   sp->xvec[sp->len++] = x;  xfrminput() can leave sp->len == XFRMMAXDEPTH, and the transport-mode receive path re-enters IPv6 input via xfrmtransreinject() with that secpath preserved. If the inner packet carries a destination-options HAO option or a type-2 routing header, xfrm6inputaddr() is called with sp->len == XFRMMAXDEPTH; the check (1 + 6 == 6) is false, so sp->xvec[sp->len++] writes one slot past the 6-element xvec[]. The write stays within the secpath allocation (invisible to KASAN); UBSANBOUNDS flags it and panics under paniconwarn.  Use "sp->len >= XFRMMAXDEPTH", matching xfrminput(). This also restores one chain level the old check rejected at sp->len == 5.    UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6input.c:309:10   index 6 is out of range for type 'xfrmstate *[6]'