Subject: CVE-2024-36886: tipc: fix UAF in error path

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

tipc: fix UAF in error path

Sam Page (sam4k) working with Trend Micro Zero Day Initiative reported
a UAF in the tipc_buf_append() error path:

BUG: KASAN: slab-use-after-free in kfree_skb_list_reason+0x47e/0x4c0
linux/net/core/skbuff.c:1183
Read of size 8 at addr ffff88804d2a7c80 by task poc/8034

CPU: 1 PID: 8034 Comm: poc Not tainted 6.8.2 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.0-debian-1.16.0-5 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack linux/lib/dump_stack.c:88
 dump_stack_lvl+0xd9/0x1b0 linux/lib/dump_stack.c:106
 print_address_description linux/mm/kasan/report.c:377
 print_report+0xc4/0x620 linux/mm/kasan/report.c:488
 kasan_report+0xda/0x110 linux/mm/kasan/report.c:601
 kfree_skb_list_reason+0x47e/0x4c0 linux/net/core/skbuff.c:1183
 skb_release_data+0x5af/0x880 linux/net/core/skbuff.c:1026
 skb_release_all linux/net/core/skbuff.c:1094
 __kfree_skb linux/net/core/skbuff.c:1108
 kfree_skb_reason+0x12d/0x210 linux/net/core/skbuff.c:1144
 kfree_skb linux/./include/linux/skbuff.h:1244
 tipc_buf_append+0x425/0xb50 linux/net/tipc/msg.c:186
 tipc_link_input+0x224/0x7c0 linux/net/tipc/link.c:1324
 tipc_link_rcv+0x76e/0x2d70 linux/net/tipc/link.c:1824
 tipc_rcv+0x45f/0x10f0 linux/net/tipc/node.c:2159
 tipc_udp_recv+0x73b/0x8f0 linux/net/tipc/udp_media.c:390
 udp_queue_rcv_one_skb+0xad2/0x1850 linux/net/ipv4/udp.c:2108
 udp_queue_rcv_skb+0x131/0xb00 linux/net/ipv4/udp.c:2186
 udp_unicast_rcv_skb+0x165/0x3b0 linux/net/ipv4/udp.c:2346
 __udp4_lib_rcv+0x2594/0x3400 linux/net/ipv4/udp.c:2422
 ip_protocol_deliver_rcu+0x30c/0x4e0 linux/net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2e4/0x520 linux/net/ipv4/ip_input.c:233
 NF_HOOK linux/./include/linux/netfilter.h:314
 NF_HOOK linux/./include/linux/netfilter.h:308
 ip_local_deliver+0x18e/0x1f0 linux/net/ipv4/ip_input.c:254
 dst_input linux/./include/net/dst.h:461
 ip_rcv_finish linux/net/ipv4/ip_input.c:449
 NF_HOOK linux/./include/linux/netfilter.h:314
 NF_HOOK linux/./include/linux/netfilter.h:308
 ip_rcv+0x2c5/0x5d0 linux/net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core+0x199/0x1e0 linux/net/core/dev.c:5534
 __netif_receive_skb+0x1f/0x1c0 linux/net/core/dev.c:5648
 process_backlog+0x101/0x6b0 linux/net/core/dev.c:5976
 __napi_poll.constprop.0+0xba/0x550 linux/net/core/dev.c:6576
 napi_poll linux/net/core/dev.c:6645
 net_rx_action+0x95a/0xe90 linux/net/core/dev.c:6781
 __do_softirq+0x21f/0x8e7 linux/kernel/softirq.c:553
 do_softirq linux/kernel/softirq.c:454
 do_softirq+0xb2/0xf0 linux/kernel/softirq.c:441
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 linux/kernel/softirq.c:381
 local_bh_enable linux/./include/linux/bottom_half.h:33
 rcu_read_unlock_bh linux/./include/linux/rcupdate.h:851
 __dev_queue_xmit+0x871/0x3ee0 linux/net/core/dev.c:4378
 dev_queue_xmit linux/./include/linux/netdevice.h:3169
 neigh_hh_output linux/./include/net/neighbour.h:526
 neigh_output linux/./include/net/neighbour.h:540
 ip_finish_output2+0x169f/0x2550 linux/net/ipv4/ip_output.c:235
 __ip_finish_output linux/net/ipv4/ip_output.c:313
 __ip_finish_output+0x49e/0x950 linux/net/ipv4/ip_output.c:295
 ip_finish_output+0x31/0x310 linux/net/ipv4/ip_output.c:323
 NF_HOOK_COND linux/./include/linux/netfilter.h:303
 ip_output+0x13b/0x2a0 linux/net/ipv4/ip_output.c:433
 dst_output linux/./include/net/dst.h:451
 ip_local_out linux/net/ipv4/ip_output.c:129
 ip_send_skb+0x3e5/0x560 linux/net/ipv4/ip_output.c:1492
 udp_send_skb+0x73f/0x1530 linux/net/ipv4/udp.c:963
 udp_sendmsg+0x1a36/0x2b40 linux/net/ipv4/udp.c:1250
 inet_sendmsg+0x105/0x140 linux/net/ipv4/af_inet.c:850
 sock_sendmsg_nosec linux/net/socket.c:730
 __sock_sendmsg linux/net/socket.c:745
 __sys_sendto+0x42c/0x4e0 linux/net/socket.c:2191
 __do_sys_sendto linux/net/socket.c:2203
 __se_sys_sendto linux/net/socket.c:2199
 __x64_sys_sendto+0xe0/0x1c0 linux/net/socket.c:2199
 do_syscall_x64 linux/arch/x86/entry/common.c:52
 do_syscall_64+0xd8/0x270 linux/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6f/0x77 linux/arch/x86/entry/entry_64.S:120
RIP: 0033:0x7f3434974f29
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48
89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
01 f0 ff ff 73 01 c3 48 8b 0d 37 8f 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007fff9154f2b8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3434974f29
RDX: 00000000000032c8 RSI: 00007fff9154f300 RDI: 0000000000000003
RBP: 00007fff915532e0 R08: 00007fff91553360 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000212 R12: 000055ed86d261d0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

In the critical scenario, either the relevant skb is freed or its
ownership is transferred into a frag_lists. In both cases, the cleanup
code must not free it again: we need to clear the skb reference earlier.

The Linux kernel CVE team has assigned CVE-2024-36886 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 4.19.314 with commit e19ec8ab0e25
	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 5.4.276 with commit 93bc2d6d16f2
	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 5.10.217 with commit 367766ff9e40
	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 5.15.159 with commit 66116556076f
	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 6.1.91 with commit 21ea04aad8a0
	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 6.6.31 with commit ffd4917c1edb
	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 6.8.10 with commit a0fbb26f8247
	Issue introduced in 4.1 with commit 1149557d64c9 and fixed in 6.9 with commit 080cbb890286

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-36886
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	net/tipc/msg.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/e19ec8ab0e25bc4803d7cc91c84e84532e2781bd
	https://git.kernel.org/stable/c/93bc2d6d16f2c3178736ba6b845b30475856dc40
	https://git.kernel.org/stable/c/367766ff9e407f8a68409b7ce4dc4d5a72afeab1
	https://git.kernel.org/stable/c/66116556076f0b96bc1aa9844008c743c8c67684
	https://git.kernel.org/stable/c/21ea04aad8a0839b4ec27ef1691ca480620e8e14
	https://git.kernel.org/stable/c/ffd4917c1edb3c3ff334fce3704fbe9c39f35682
	https://git.kernel.org/stable/c/a0fbb26f8247e326a320e2cb4395bfb234332c90
	https://git.kernel.org/stable/c/080cbb890286cd794f1ee788bbc5463e2deb7c2b