In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack()<\/p>\n
When tcp_send_synack() replaces the cloned SYN skb at the head of the
\nretransmit queue with a copy, it frees the original with
\ntcp_rtx_queue_unlink_and_free() and only repairs tp->highest_sack.
\ntp->retransmit_skb_hint keeps pointing at the freed
\nskbuff_fclone_cache object.<\/p>\n
The dangling hint is read in tcp_verify_retransmit_hint() and used as
\nthe root of the rbtree walk in tcp_xmit_retransmit_queue(). An
\nunprivileged TFO client (sendmsg(MSG_FASTOPEN)) can arm the hint with
\nan attacker-supplied ICMP fragmentation-needed message, after which a
\nsimultaneous open frees the armed SYN skb:<\/p>\n
BUG: KASAN: slab-use-after-free in tcp_mark_skb_lost (net\/ipv4\/tcp_input.c:1316)
\n Read of size 4 at addr ffff88800604d928 by task swapper\/1\/0
\n Call Trace:
\n tcp_mark_skb_lost (net\/ipv4\/tcp_input.c:1316)
\n tcp_simple_retransmit (net\/ipv4\/tcp_input.c:3158)
\n tcp_v4_err (net\/ipv4\/tcp_ipv4.c:587)<\/p>\n
Sync the hint to the copy.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack()<\/p>\n
When tcp_send_synack() replaces the cloned SYN skb at the head<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-34177","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/34177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=34177"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34177"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}