CVE-2024-40961: ipv6: prevent possible NULL deref in fib6_nh_init()

Published Jul 12, 2024
·
Updated

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

ipv6: prevent possible NULL deref in fib6nhinit()

syzbot reminds us that in6devget() can return NULL.

fib6nhinit() ip6validategw( &idev ) ip6routechecknh( idev ) idev = in6devget(dev); // can be NULL

Oops: general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7] CPU: 0 PID: 11237 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:fib6nhinit+0x640/0x2160 net/ipv6/route.c:3606 Code: 00 00 fc ff df 4c 8b 64 24 58 48 8b 44 24 28 4c 8b 74 24 30 48 89 c1 48 89 44 24 28 48 8d 98 e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 b3 17 00 00 8b 1b 31 ff 89 de e8 b8 8b RSP: 0018:ffffc900032775a0 EFLAGS: 00010202 RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffffc90003277a54 RDI: ffff88802b3a08d8 RBP: ffffc900032778b0 R08: 00000000000002fc R09: 0000000000000000 R10: 00000000000002fc R11: 0000000000000000 R12: ffff88802b3a08b8 R13: 1ffff9200064eec8 R14: ffffc90003277a00 R15: dffffc0000000000 FS: 00007f940feb06c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000245e8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip6routeinfocreate+0x99e/0x12b0 net/ipv6/route.c:3809 ip6routeadd+0x28/0x160 net/ipv6/route.c:3853 ipv6routeioctl+0x588/0x870 net/ipv6/route.c:4483 inet6ioctl+0x21a/0x280 net/ipv6/afinet6.c:579 sockdoioctl+0x158/0x460 net/socket.c:1222 sockioctl+0x629/0x8e0 net/socket.c:1341 vfsioctl fs/ioctl.c:51 [inline] dosysioctl fs/ioctl.c:907 [inline] sesysioctl+0xfc/0x170 fs/ioctl.c:893 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xf3/0x230 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x77/0x7f RIP: 0033:0x7f940f07cea9

Other sources

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

ipv6: prevent possible NULL deref in fib6nhinit()

syzbot reminds us that in6devget() can return NULL.

fib6nhinit() ip6validategw( &idev ) ip6routechecknh( idev ) idev = in6devget(dev); // can be NULL

Oops: general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7] CPU: 0 PID: 11237 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:fib6nhinit+0x640/0x2160 net/ipv6/route.c:3606 Code: 00 00 fc ff df 4c 8b 64 24 58 48 8b 44 24 28 4c 8b 74 24 30 48 89 c1 48 89 44 24 28 48 8d 98 e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 b3 17 00 00 8b 1b 31 ff 89 de e8 b8 8b RSP: 0018:ffffc900032775a0 EFLAGS: 00010202 RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffffc90003277a54 RDI: ffff88802b3a08d8 RBP: ffffc900032778b0 R08: 00000000000002fc R09: 0000000000000000 R10: 00000000000002fc R11: 0000000000000000 R12: ffff88802b3a08b8 R13: 1ffff9200064eec8 R14: ffffc90003277a00 R15: dffffc0000000000 FS: 00007f940feb06c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000245e8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ip6routeinfocreate+0x99e/0x12b0 net/ipv6/route.c:3809 ip6routeadd+0x28/0x160 net/ipv6/route.c:3853 ipv6routeioctl+0x588/0x870 net/ipv6/route.c:4483 inet6ioctl+0x21a/0x280 net/ipv6/afinet6.c:579 sockdoioctl+0x158/0x460 net/socket.c:1222 sockioctl+0x629/0x8e0 net/socket.c:1341 vfsioctl fs/ioctl.c:51 [inline] dosysioctl fs/ioctl.c:907 [inline] sesysioctl+0xfc/0x170 fs/ioctl.c:893 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xf3/0x230 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x77/0x7f RIP: 0033:0x7f940f07cea9

Red Hat

Affected Software

23 affected componentsFixes available
redhat/kernel<5.4.279
5.4.279
redhat/kernel<5.10.221
5.10.221
redhat/kernel<5.15.162
5.15.162
redhat/kernel<6.1.96
6.1.96
redhat/kernel<6.6.36
6.6.36
redhat/kernel<6.9.7
6.9.7
redhat/kernel<6.10
6.10
Linux Linux kernel>=4.17<5.4.279
Linux Linux kernel>=5.5<5.10.221
Linux Linux kernel>=5.11<5.15.162
Linux Linux kernel>=5.16<6.1.96
Linux Linux kernel>=6.2<6.6.36
Linux Linux kernel>=6.7<6.9.7
Linux Linux kernel=6.10-rc1
Linux Linux kernel=6.10-rc2
Linux Linux kernel=6.10-rc3
Linux Linux kernel=6.10-rc4
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.25-1
debian/linux-6.1
6.1.129-1~deb11u1
IBM Security Verify Governance<=ISVG 10.0.2
IBM Security Verify Governance - Identity Manager virtual appliance component<=ISVG 10.0.2
Microsoft azl3 kernel 6.6.47.1-1
Microsoft azl3 kernel 6.6.35.1-5

Event History

Jul 12, 2024
CVE Published
via MITRE·12:32 PM
Data Sourced
via MITRE·12:32 PM
Description
Data Sourced
via NVD·01:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Sep 11, 2024
Data Sourced
via Microsoft·07:00 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·07:00 AM
Affected Software
Updated
via Microsoft·07:00 AM
DescriptionSeverity
Apr 27, 2025
Data Sourced
via Ubuntu·06:15 PM
RemedyDescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2024-40961?

CVE-2024-40961 has a medium severity rating due to the potential NULL dereference issue in the Linux kernel.

2

How do I fix CVE-2024-40961?

To fix CVE-2024-40961, update the Linux kernel to one of the following versions: 5.4.279, 5.10.221, 5.15.162, 6.1.96, 6.6.36, 6.9.7, or 6.10.

3

Which Linux kernel versions are affected by CVE-2024-40961?

CVE-2024-40961 affects Linux kernel versions prior to 5.4.279, 5.10.221, 5.15.162, 6.1.96, 6.6.36, 6.9.7, and 6.10.

4

What is the impact of CVE-2024-40961?

The impact of CVE-2024-40961 could lead to potential crashes or instability in systems using the affected Linux kernel versions.

5

Are there any mitigations for CVE-2024-40961 before applying a fix?

Currently, there are no known mitigations for CVE-2024-40961, so applying the kernel update is the best course of action.

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CVE-2024-40961 - ipv6: prevent possible NULL deref in fib6_nh_init() - SecAlerts