Bug 1227813 (CVE-2024-40960)

Summary:	VUL-0: CVE-2024-40960: kernel: ipv6: prevent possible NULL dereference in rt6_probe()
Product:	[Novell Products] SUSE Security Incidents	Reporter:	SMASH SMASH <smash_bz>
Component:	Incidents	Assignee:	CVE kernel patch monkeys <cve-kpm>
Status:	NEW ---	QA Contact:	Security Team bot <security-team>
Severity:	Normal
Priority:	P3 - Medium	CC:	davide.benini, denis.kirjanov, gianluca.gabrielli, miroslav.franc, mkubecek
Version:	unspecified
Target Milestone:	---
Hardware:	Other
OS:	Other
URL:	https://smash.suse.de/issue/413887/
Whiteboard:	CVSSv3.1:SUSE:CVE-2024-40960:5.5:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Found By:	Security Response Team	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description SMASH SMASH 2024-07-15 13:16:50 UTC

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

ipv6: prevent possible NULL dereference in rt6_probe()

syzbot caught a NULL dereference in rt6_probe() [1]

Bail out if  __in6_dev_get() returns NULL.

[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cb: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000658-0x000000000000065f]
CPU: 1 PID: 22444 Comm: syz-executor.0 Not tainted 6.10.0-rc2-syzkaller-00383-gb8481381d4e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
 RIP: 0010:rt6_probe net/ipv6/route.c:656 [inline]
 RIP: 0010:find_match+0x8c4/0xf50 net/ipv6/route.c:758
Code: 14 fd f7 48 8b 85 38 ff ff ff 48 c7 45 b0 00 00 00 00 48 8d b8 5c 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 19
RSP: 0018:ffffc900034af070 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90004521000
RDX: 00000000000000cb RSI: ffffffff8990d0cd RDI: 000000000000065c
RBP: ffffc900034af150 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000002 R12: 000000000000000a
R13: 1ffff92000695e18 R14: ffff8880244a1d20 R15: 0000000000000000
FS:  00007f4844a5a6c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31b27000 CR3: 000000002d42c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  rt6_nh_find_match+0xfa/0x1a0 net/ipv6/route.c:784
  nexthop_for_each_fib6_nh+0x26d/0x4a0 net/ipv4/nexthop.c:1496
  __find_rr_leaf+0x6e7/0xe00 net/ipv6/route.c:825
  find_rr_leaf net/ipv6/route.c:853 [inline]
  rt6_select net/ipv6/route.c:897 [inline]
  fib6_table_lookup+0x57e/0xa30 net/ipv6/route.c:2195
  ip6_pol_route+0x1cd/0x1150 net/ipv6/route.c:2231
  pol_lookup_func include/net/ip6_fib.h:616 [inline]
  fib6_rule_lookup+0x386/0x720 net/ipv6/fib6_rules.c:121
  ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline]
  ip6_route_output_flags+0x1d0/0x640 net/ipv6/route.c:2651
  ip6_dst_lookup_tail.constprop.0+0x961/0x1760 net/ipv6/ip6_output.c:1147
  ip6_dst_lookup_flow+0x99/0x1d0 net/ipv6/ip6_output.c:1250
  rawv6_sendmsg+0xdab/0x4340 net/ipv6/raw.c:898
  inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg net/socket.c:745 [inline]
  sock_write_iter+0x4b8/0x5c0 net/socket.c:1160
  new_sync_write fs/read_write.c:497 [inline]
  vfs_write+0x6b6/0x1140 fs/read_write.c:590
  ksys_write+0x1f8/0x260 fs/read_write.c:643
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-40960
https://www.cve.org/CVERecord?id=CVE-2024-40960
https://git.kernel.org/stable/c/1ed9849fdf9a1a617129346b11d2094ca26828dc
https://git.kernel.org/stable/c/51ee2f7c30790799d0ec30c0ce0c743e58f046f2
https://git.kernel.org/stable/c/569c9d9ea6648d099187527b93982f406ddcebc0
https://git.kernel.org/stable/c/6eed6d3cd19ff3cfa83aeceed86da14abaf7417b
https://git.kernel.org/stable/c/73e7c8ca6ad76f29b2c99c20845a6f3b203ff0c6
https://git.kernel.org/stable/c/b86762dbe19a62e785c189f313cda5b989931f37
https://git.kernel.org/stable/c/d66fc4826127c82f99c4033380f8e93833d331c7
https://git.kernel.org/stable/c/f0cda984e4e634b221dbf9642b8ecc5b4806b41e
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-40960.mbox