CVE-2025-21653 in Linux
Sumário
de VulDB • 05/06/2026
No kernel do Linux, a seguinte vulnerabilidade foi resolvida:
net_sched: cls_flow: validar o atributo TCA_FLOW_RSHIFT
O syzbot descobriu que o atributo TCA_FLOW_RSHIFT não estava sendo validado. O deslocamento à direita (right shift) de um inteiro de 32 bits é indefinido para valores grandes de deslocamento.
UBSAN: shift-out-of-bounds em net/sched/cls_flow.c:329:23 expoente do deslocamento 9445 é muito grande para o tipo 'u32' (também conhecido como 'unsigned int') de 32 bits CPU: 1 UID: 0 PID: 54 Comm: kworker/u8:3 Não contaminado 6.13.0-rc3-syzkaller-00180-g4f619d518db9 #0 Nome do hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468 flow_classify+0x24d5/0x25b0 net/sched/cls_flow.c:329 tc_classify include/net/tc_wrapper.h:197 [inline]
__tcf_classify net/sched/cls_api.c:1771 [inline]
tcf_classify+0x420/0x1160 net/sched/cls_api.c:1867 sfb_classify net/sched/sch_sfb.c:260 [inline]
sfb_enqueue+0x3ad/0x18b0 net/sched/sch_sfb.c:318 dev_qdisc_enqueue+0x4b/0x290 net/core/dev.c:3793 __dev_xmit_skb net/core/dev.c:3889 [inline]
__dev_queue_xmit+0xf0e/0x3f50 net/core/dev.c:4400 dev_queue_xmit include/linux/netdevice.h:3168 [inline]
neigh_hh_output include/net/neighbour.h:523 [inline]
neigh_output include/net/neighbour.h:537 [inline]
ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 iptunnel_xmit+0x55d/0x9b0 net/ipv4/ip_tunnel_core.c:82 udp_tunnel_xmit_skb+0x262/0x3b0 net/ipv4/udp_tunnel_core.c:173 geneve_xmit_skb drivers/net/geneve.c:916 [inline]
geneve_xmit+0x21dc/0x2d00 drivers/net/geneve.c:1039 __netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3606 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4434
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