CVE-2021-47082 Affecting kernel-default package, versions <5.14.21-150400.24.116.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-SLES154-KERNELDEFAULT-6618361
- published18 Apr 2024
- disclosed16 Apr 2024
Introduced: 16 Apr 2024
CVE-2021-47082 (opens in a new tab)How to fix?
Upgrade SLES:15.4 kernel-default to version 5.14.21-150400.24.116.1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-default package and not the kernel-default package as distributed by SLES.
See How to fix? for SLES:15.4 relevant fixed versions and status.
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
References
- https://www.suse.com/security/cve/CVE-2021-47082.html
- https://bugzilla.suse.com/1220969
- https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681
- https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df
- https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5
- https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757
- https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904