CVE-2024-40958netns: Make get_net_ns() handle zero refcount net
- 7.8HighCVSS base score
- 0.27%Exploitation in 30 daysEPSS · top 81% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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
Timeline
ID reserved
By Linux
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.27% · top 81% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f – < 3a6cd326ead7c8bb1f64486789a01974a9f1ad55
- affected 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f – < 2b82028a1f5ee3a8e04090776b10c534144ae77b
- affected 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f – < cb7f811f638a14590ff98f53c6dd1fb54627d940
- affected 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f – < 1b631bffcb2c09551888f3c723f4365c91fe05ef
- affected 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f – < ef0394ca25953ea0eddcc82feae1f750451f1876
- affected 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f – < 3af28df0d883e8c89a29ac31bc65f9023485743b
- affected 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f – < ff960f9d3edbe08a736b5a224d91a305ccc946b0
- affected 5.2
- unaffected < 5.2
- unaffected 5.4.279 – ≤ 5.4.*
- unaffected 5.10.221 – ≤ 5.10.*
- unaffected 5.15.162 – ≤ 5.15.*
- unaffected 6.1.96 – ≤ 6.1.*
- unaffected 6.6.36 – ≤ 6.6.*
- unaffected 6.9.7 – ≤ 6.9.*
- unaffected 6.10 – ≤ *
References
References11
- https://git.kernel.org/stable/c/3a6cd326ead7c8bb1f64486789a01974a9f1ad55 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/2b82028a1f5ee3a8e04090776b10c534144ae77b (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/cb7f811f638a14590ff98f53c6dd1fb54627d940 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/1b631bffcb2c09551888f3c723f4365c91fe05ef (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/ef0394ca25953ea0eddcc82feae1f750451f1876 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/3af28df0d883e8c89a29ac31bc65f9023485743b (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/ff960f9d3edbe08a736b5a224d91a305ccc946b0 (opens in a new tab)x_transferred
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-613116.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-355557.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2024-38755 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2024-40958)Record last updated .