7.8

CVE-2022-50310

In the Linux kernel, the following vulnerability has been resolved:

ip6mr: fix UAF issue in ip6mr_sk_done() when addrconf_init_net() failed

If the initialization fails in calling addrconf_init_net(), devconf_all is
the pointer that has been released. Then ip6mr_sk_done() is called to
release the net, accessing devconf->mc_forwarding directly causes invalid
pointer access.

The process is as follows:
setup_net()
	ops_init()
		addrconf_init_net()
		all = kmemdup(...)           ---> alloc "all"
		...
		net->ipv6.devconf_all = all;
		__addrconf_sysctl_register() ---> failed
		...
		kfree(all);                  ---> ipv6.devconf_all invalid
		...
	ops_exit_list()
		...
		ip6mr_sk_done()
			devconf = net->ipv6.devconf_all;
			//devconf is invalid pointer
			if (!devconf || !atomic_read(&devconf->mc_forwarding))

The following is the Call Trace information:
BUG: KASAN: use-after-free in ip6mr_sk_done+0x112/0x3a0
Read of size 4 at addr ffff888075508e88 by task ip/14554
Call Trace:
<TASK>
dump_stack_lvl+0x8e/0xd1
print_report+0x155/0x454
kasan_report+0xba/0x1f0
kasan_check_range+0x35/0x1b0
ip6mr_sk_done+0x112/0x3a0
rawv6_close+0x48/0x70
inet_release+0x109/0x230
inet6_release+0x4c/0x70
sock_release+0x87/0x1b0
igmp6_net_exit+0x6b/0x170
ops_exit_list+0xb0/0x170
setup_net+0x7ac/0xbd0
copy_net_ns+0x2e6/0x6b0
create_new_namespaces+0x382/0xa50
unshare_nsproxy_namespaces+0xa6/0x1c0
ksys_unshare+0x3a4/0x7e0
__x64_sys_unshare+0x2d/0x40
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f7963322547

</TASK>
Allocated by task 14554:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0xa1/0xb0
__kmalloc_node_track_caller+0x4a/0xb0
kmemdup+0x28/0x60
addrconf_init_net+0x1be/0x840
ops_init+0xa5/0x410
setup_net+0x5aa/0xbd0
copy_net_ns+0x2e6/0x6b0
create_new_namespaces+0x382/0xa50
unshare_nsproxy_namespaces+0xa6/0x1c0
ksys_unshare+0x3a4/0x7e0
__x64_sys_unshare+0x2d/0x40
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

Freed by task 14554:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x40
____kasan_slab_free+0x155/0x1b0
slab_free_freelist_hook+0x11b/0x220
__kmem_cache_free+0xa4/0x360
addrconf_init_net+0x623/0x840
ops_init+0xa5/0x410
setup_net+0x5aa/0xbd0
copy_net_ns+0x2e6/0x6b0
create_new_namespaces+0x382/0xa50
unshare_nsproxy_namespaces+0xa6/0x1c0
ksys_unshare+0x3a4/0x7e0
__x64_sys_unshare+0x2d/0x40
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
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Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 5.18 < 6.0.6
Linux ≫ Linux Kernel Version6.1 Updaterc1
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.02% 0.042
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.