7.8
HIGH
CVE-2021-47082
Linux tun Security Enhanced Linux Double Free
Description

In the Linux kernel, the following vulnerability has been resolved: tun: avoid double free in tun_free_netdev Avoid double free in tun_free_netdev() by moving the dev->tstats and tun->security allocs to a new ndo_init routine (tun_net_init()) that will be called by register_netdevice(). ndo_init is paired with the desctructor (tun_free_netdev()), so if there's an error in register_netdevice() the destructor will handle the frees. BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605 CPU: 0 PID: 25750 Comm: syz-executor416 Not tainted 5.16.0-rc2-syzk #1 Hardware name: Red Hat KVM, BIOS Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106 print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:247 kasan_report_invalid_free+0x55/0x80 mm/kasan/report.c:372 ____kasan_slab_free mm/kasan/common.c:346 [inline] __kasan_slab_free+0x107/0x120 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook mm/slub.c:1749 [inline] slab_free mm/slub.c:3513 [inline] kfree+0xac/0x2d0 mm/slub.c:4561 selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605 security_tun_dev_free_security+0x4f/0x90 security/security.c:2342 tun_free_netdev+0xe6/0x150 drivers/net/tun.c:2215 netdev_run_todo+0x4df/0x840 net/core/dev.c:10627 rtnl_unlock+0x13/0x20 net/core/rtnetlink.c:112 __tun_chr_ioctl+0x80c/0x2870 drivers/net/tun.c:3302 tun_chr_ioctl+0x2f/0x40 drivers/net/tun.c:3311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae

INFO

Published Date :

March 4, 2024, 6:15 p.m.

Last Modified :

Jan. 14, 2025, 3 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

5.9

Exploitability Score :

1.8
Affected Products

The following products are affected by CVE-2021-47082 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-47082.

URL Resource
https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681 Patch
https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df Patch
https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5 Patch
https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757 Patch
https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904 Patch
https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681 Patch
https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df Patch
https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5 Patch
https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757 Patch
https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904 Patch

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-47082 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-47082 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jan. 14, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE NIST CWE-415
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 4.19.280 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.240 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.136 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.12 *cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.16:rc6:*:*:*:*:*:*
    Changed Reference Type https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681 No Types Assigned https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681 Patch
    Changed Reference Type https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681 No Types Assigned https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681 Patch
    Changed Reference Type https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df No Types Assigned https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df Patch
    Changed Reference Type https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df No Types Assigned https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df Patch
    Changed Reference Type https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5 No Types Assigned https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5 Patch
    Changed Reference Type https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5 No Types Assigned https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5 Patch
    Changed Reference Type https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757 No Types Assigned https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757 Patch
    Changed Reference Type https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757 No Types Assigned https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757 Patch
    Changed Reference Type https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904 No Types Assigned https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904 Patch
    Changed Reference Type https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904 No Types Assigned https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904 Patch
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681
    Added Reference https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df
    Added Reference https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5
    Added Reference https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757
    Added Reference https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 28, 2024

    Action Type Old Value New Value
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Mar. 04, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: tun: avoid double free in tun_free_netdev Avoid double free in tun_free_netdev() by moving the dev->tstats and tun->security allocs to a new ndo_init routine (tun_net_init()) that will be called by register_netdevice(). ndo_init is paired with the desctructor (tun_free_netdev()), so if there's an error in register_netdevice() the destructor will handle the frees. BUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605 CPU: 0 PID: 25750 Comm: syz-executor416 Not tainted 5.16.0-rc2-syzk #1 Hardware name: Red Hat KVM, BIOS Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106 print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:247 kasan_report_invalid_free+0x55/0x80 mm/kasan/report.c:372 ____kasan_slab_free mm/kasan/common.c:346 [inline] __kasan_slab_free+0x107/0x120 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook mm/slub.c:1749 [inline] slab_free mm/slub.c:3513 [inline] kfree+0xac/0x2d0 mm/slub.c:4561 selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605 security_tun_dev_free_security+0x4f/0x90 security/security.c:2342 tun_free_netdev+0xe6/0x150 drivers/net/tun.c:2215 netdev_run_todo+0x4df/0x840 net/core/dev.c:10627 rtnl_unlock+0x13/0x20 net/core/rtnetlink.c:112 __tun_chr_ioctl+0x80c/0x2870 drivers/net/tun.c:3302 tun_chr_ioctl+0x2f/0x40 drivers/net/tun.c:3311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
    Added Reference Linux https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757 [No types assigned]
    Added Reference Linux https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681 [No types assigned]
    Added Reference Linux https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904 [No types assigned]
    Added Reference Linux https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5 [No types assigned]
    Added Reference Linux https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-47082 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-47082 weaknesses.

CVSS31 - Vulnerability Scoring System
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Latest DB Update: Jul. 14, 2025 16:44