CVE-2024-40958: netns: Make get_net_ns() handle zero refcount net
First published: Fri Jul 12 2024(Updated: )
In the Linux kernel, the following vulnerability has been resolved: netns: Make get_net_ns() handle zero refcount net Syzkaller hit a warning: refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 7890 at lib/refcount.c:25 refcount_warn_saturate+0xdf/0x1d0 Modules linked in: CPU: 3 PID: 7890 Comm: tun Not tainted 6.10.0-rc3-00100-gcaa4f9578aba-dirty #310 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:refcount_warn_saturate+0xdf/0x1d0 Code: 41 49 04 31 ff 89 de e8 9f 1e cd fe 84 db 75 9c e8 76 26 cd fe c6 05 b6 41 49 04 01 90 48 c7 c7 b8 8e 25 86 e8 d2 05 b5 fe 90 <0f> 0b 90 90 e9 79 ff ff ff e8 53 26 cd fe 0f b6 1 RSP: 0018:ffff8881067b7da0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811c72ac RDX: ffff8881026a2140 RSI: ffffffff811c72b5 RDI: 0000000000000001 RBP: ffff8881067b7db0 R08: 0000000000000000 R09: 205b5d3730353139 R10: 0000000000000000 R11: 205d303938375420 R12: ffff8881086500c4 R13: ffff8881086500c4 R14: ffff8881086500b0 R15: ffff888108650040 FS: 00007f5b2961a4c0(0000) GS:ffff88823bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d7ed36fd18 CR3: 00000001482f6000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? show_regs+0xa3/0xc0 ? __warn+0xa5/0x1c0 ? refcount_warn_saturate+0xdf/0x1d0 ? report_bug+0x1fc/0x2d0 ? refcount_warn_saturate+0xdf/0x1d0 ? handle_bug+0xa1/0x110 ? exc_invalid_op+0x3c/0xb0 ? asm_exc_invalid_op+0x1f/0x30 ? __warn_printk+0xcc/0x140 ? __warn_printk+0xd5/0x140 ? refcount_warn_saturate+0xdf/0x1d0 get_net_ns+0xa4/0xc0 ? __pfx_get_net_ns+0x10/0x10 open_related_ns+0x5a/0x130 __tun_chr_ioctl+0x1616/0x2370 ? __sanitizer_cov_trace_switch+0x58/0xa0 ? __sanitizer_cov_trace_const_cmp2+0x1c/0x30 ? __pfx_tun_chr_ioctl+0x10/0x10 tun_chr_ioctl+0x2f/0x40 __x64_sys_ioctl+0x11b/0x160 x64_sys_call+0x1211/0x20d0 do_syscall_64+0x9e/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b28f165d7 Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 8 RSP: 002b:00007ffc2b59c5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b28f165d7 RDX: 0000000000000000 RSI: 00000000000054e3 RDI: 0000000000000003 RBP: 00007ffc2b59c650 R08: 00007f5b291ed8c0 R09: 00007f5b2961a4c0 R10: 0000000029690010 R11: 0000000000000246 R12: 0000000000400730 R13: 00007ffc2b59cf40 R14: 0000000000000000 R15: 0000000000000000 </TASK> Kernel panic - not syncing: kernel: panic_on_warn set ... This is trigger as below: ns0 ns1 tun_set_iff() //dev is tun0 tun->dev = dev //ip link set tun0 netns ns1 put_net() //ref is 0 __tun_chr_ioctl() //TUNGETDEVNETNS net = dev_net(tun->dev); open_related_ns(&net->ns, get_net_ns); //ns1 get_net_ns() get_net() //addition on 0 Use maybe_get_net() in get_net_ns in case net's ref is zero to fix this
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Linux kernel | >=5.2<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 | |
| 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 |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.11.10-1 6.12.5-1 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- https://git.kernel.org/stable/c/1b631bffcb2c09551888f3c723f4365c91fe05ef
- https://git.kernel.org/stable/c/2b82028a1f5ee3a8e04090776b10c534144ae77b
- https://git.kernel.org/stable/c/3a6cd326ead7c8bb1f64486789a01974a9f1ad55
- https://git.kernel.org/stable/c/3af28df0d883e8c89a29ac31bc65f9023485743b
- https://git.kernel.org/stable/c/cb7f811f638a14590ff98f53c6dd1fb54627d940
- https://git.kernel.org/stable/c/ef0394ca25953ea0eddcc82feae1f750451f1876
- https://git.kernel.org/stable/c/ff960f9d3edbe08a736b5a224d91a305ccc946b0
- https://git.kernel.org/linus/ff960f9d3edbe08a736b5a224d91a305ccc946b0
- https://security-tracker.debian.org/tracker/CVE-2024-40958
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-40958
- https://nvd.nist.gov/vuln/detail/CVE-2024-40958
- https://launchpad.net/bugs/cve/CVE-2024-40958
- https://ubuntu.com/security/CVE-2024-40958
- https://access.redhat.com/errata/RHSA-2024:5363
- https://access.redhat.com/errata/RHSA-2024:7001
- https://access.redhat.com/errata/RHSA-2024:7000
- https://bugzilla.redhat.com/show_bug.cgi?id=2297542
- agent/title
- agent/type
- collector/nvd-api
- source/NVD
- agent/software-canonical-lookup
- agent/severity
- agent/remedy
- agent/author
- agent/first-publish-date
- agent/weakness
- agent/references
- collector/redhat-bugzilla
- source/Red Hat
- alias/CVE-2024-40958
- agent/tags
- collector/usn-cve
- source/Ubuntu
- agent/description
- collector/nvd-cve
- agent/event
- collector/security-tracker-debian
- source/Debian
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/trending
- vendor/linux
- canonical/linux linux kernel
- version/linux linux kernel/5.2
- version/linux linux kernel/5.5
- version/linux linux kernel/5.11
- version/linux linux kernel/5.16
- version/linux linux kernel/6.2
- version/linux linux kernel/6.7
- version/linux linux kernel/6.10-rc1
- version/linux linux kernel/6.10-rc2
- version/linux linux kernel/6.10-rc3
- version/linux linux kernel/6.10-rc4
- package-manager/redhat
- package-manager/debian