In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
xfrm: reject optional IPTFS templates in outbound policies<\/p>\n
syzbot reported a stack-out-of-bounds read in xfrm_state_find()
\nwhich flows from xfrm_tmpl_resolve_one().<\/p>\n
Commit 3d776e31c841 (“xfrm: Reject optional tunnel\/BEET mode
\ntemplates in outbound policies”) disallowed optional tunnel and
\nBEET in outbound policies to prevent this. Later when IPTFS
\nadded, it was not covered by that fix and can still trigger
\nthe out-of-bounds read;<\/p>\n
Extend the check to disallow optional IPTFS in outbound policies
\nas well. IPTFS should be identical to tunnel mode.
\nIN and FWD policies are not affected: xfrm_tmpl_resolve_one()
\nis only reachable via the outbound path.<\/p>\n
Reproducer, before:<\/p>\n
ip link add dummy0 type dummy
\nip link set dummy0 up
\nip addr add 10.1.1.1\/24 dev dummy0
\nip xfrm policy add src 10.1.1.1\/32 dst 10.1.1.2\/32 dir out tmpl
\n src fc00::dead:1 dst fc00::dead:2 proto esp reqid 1 mode iptfs
\n level use tmpl src fc00::dead:1 dst fc00::dead:2 proto esp reqid
\n 2 mode transport
\nping -W 1 -c 1 10.1.1.2
\nPING 10.1.1.2 (10.1.1.2) 56(84) bytes of data.<\/p>\n
[ 64.168420] ==================================================================
\n[ 64.169977] BUG: KASAN: stack-out-of-bounds in __xfrm6_addr_hash+0x11e\/0x170
\n[ 64.169977] Read of size 4 at addr ffff88800e1ffd20 by task ping\/2844<\/p>\n
[ 64.169977] CPU: 2 UID: 0 PID: 2844 Comm: ping Not tainted 7.1.0-rc7-00180-geb23b588430a #98 PREEMPT(full)
\n[ 64.169977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04\/01\/2014
\n[ 64.169977] Call Trace:
\n[ 64.169977]
\n[ 64.169977] dump_stack_lvl+0x47\/0x70
\n[ 64.169977] ? __xfrm6_addr_hash+0x11e\/0x170
\n[ 64.169977] print_report+0x152\/0x4b0
\n[ 64.169977] ? ksys_mmap_pgoff+0x6d\/0xa0
\n[ 64.169977] ? entry_SYSCALL_64_after_hwframe+0x76\/0x7e
\n[ 64.169977] ? rcu_read_unlock_sched+0xa\/0x20
\n[ 64.169977] ? __virt_addr_valid+0x21b\/0x230
\n[ 64.169977] ? __xfrm6_addr_hash+0x11e\/0x170
\n[ 64.169977] kasan_report+0xa8\/0xd0
\n[ 64.169977] ? __xfrm6_addr_hash+0x11e\/0x170
\n[ 64.169977] __xfrm6_addr_hash+0x11e\/0x170
\n[ 64.169977] __xfrm_dst_hash+0x24\/0xc0
\n[ 64.169977] xfrm_state_find+0xa2d\/0x2f90
\n[ 64.169977] ? __pfx_xfrm_state_find+0x10\/0x10
\n[ 64.169977] ? __pfx_ftrace_graph_ret_addr+0x10\/0x10
\n[ 64.169977] ? __pfx_ftrace_graph_ret_addr+0x10\/0x10
\n[ 64.169977] xfrm_tmpl_resolve_one+0x210\/0x570
\n[ 64.169977] ? __pfx_xfrm_tmpl_resolve_one+0x10\/0x10
\n[ 64.169977] ? __pfx_stack_trace_consume_entry+0x10\/0x10
\n[ 64.169977] ? kernel_text_address+0x5b\/0x80
\n[ 64.169977] ? __kernel_text_address+0xe\/0x30
\n[ 64.169977] ? unwind_get_return_address+0x5e\/0x90
\n[ 64.169977] ? arch_stack_walk+0x8c\/0xe0
\n[ 64.169977] xfrm_tmpl_resolve+0x130\/0x200
\n[ 64.169977] ? __pfx_xfrm_tmpl_resolve+0x10\/0x10
\n[ 64.169977] ? __pfx_xfrm_policy_inexact_lookup_rcu+0x10\/0x10
\n[ 64.169977] ? __refcount_add_not_zero.constprop.0+0xb2\/0x110
\n[ 64.169977] ? __pfx___refcount_add_not_zero.constprop.0+0x10\/0x10
\n[ 64.169977] xfrm_resolve_and_create_bundle+0xd5\/0x310
\n[ 64.169977] ? __pfx_xfrm_resolve_and_create_bundle+0x10\/0x10
\n[ 64.169977] ? __pfx_xfrm_policy_lookup_bytype+0x10\/0x10
\n[ 64.169977] ? __pfx_xfrm_policy_lookup_bytype+0x10\/0x10
\n[ 64.169977] xfrm_lookup_with_ifid+0x3d8\/0xb80
\n[ 64.169977] ? __pfx_xfrm_lookup_with_ifid+0x10\/0x10
\n[ 64.169977] ? ip_route_output_key_hash+0xc6\/0x110
\n[ 64.169977] ? kasan_save_track+0x10\/0x30
\n[ 64.169977] xfrm_lookup_route+0x18\/0xe0
\n[ 64.169977] ip4_datagram_release_cb+0x4c9\/0x530
\n[ 64.169977] ? __pfx_ip4_datagram_release_cb+0x10\/0x10
\n[ 64.169977] ? do_raw_spin_lock+0x71\/0xc0
\n[ 64.169977] ? __pfx_do_raw_spin_lock+0x10\/0x10
\n[ 64.169977] release_sock+0xb0\/0x170
\n[ 64.169977] udp_connect+0x43\/0x50
\n[ 64.169977] __sys_connect+0xa6\/0x100
\n[ 64.169977] ? alloc_fd+0x2e9\/0x300
\n[ 64.169977] ? __pfx___sys_connect+0x10\/0x10
\n[ 64.169977] ? preempt_latency
\n—truncated—<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
xfrm: reject optional IPTFS templates in outbound policies<\/p>\n
syzbot reported a stack-out-of-bounds read in xfrm_state_find()
\nwhich f<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5471","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5471","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=5471"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5471"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5471"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}