{"id":"CVE-2021-47082","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntun: avoid double free in tun_free_netdev\n\nAvoid double free in tun_free_netdev() by moving the\ndev-\u003etstats and tun-\u003esecurity allocs to a new ndo_init routine\n(tun_net_init()) that will be called by register_netdevice().\nndo_init is paired with the desctructor (tun_free_netdev()),\nso if there's an error in register_netdevice() the destructor\nwill handle the frees.\n\nBUG: KASAN: double-free or invalid-free in selinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605\n\nCPU: 0 PID: 25750 Comm: syz-executor416 Not tainted 5.16.0-rc2-syzk #1\nHardware name: Red Hat KVM, BIOS\nCall Trace:\n\u003cTASK\u003e\n__dump_stack lib/dump_stack.c:88 [inline]\ndump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106\nprint_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:247\nkasan_report_invalid_free+0x55/0x80 mm/kasan/report.c:372\n____kasan_slab_free mm/kasan/common.c:346 [inline]\n__kasan_slab_free+0x107/0x120 mm/kasan/common.c:374\nkasan_slab_free include/linux/kasan.h:235 [inline]\nslab_free_hook mm/slub.c:1723 [inline]\nslab_free_freelist_hook mm/slub.c:1749 [inline]\nslab_free mm/slub.c:3513 [inline]\nkfree+0xac/0x2d0 mm/slub.c:4561\nselinux_tun_dev_free_security+0x1a/0x20 security/selinux/hooks.c:5605\nsecurity_tun_dev_free_security+0x4f/0x90 security/security.c:2342\ntun_free_netdev+0xe6/0x150 drivers/net/tun.c:2215\nnetdev_run_todo+0x4df/0x840 net/core/dev.c:10627\nrtnl_unlock+0x13/0x20 net/core/rtnetlink.c:112\n__tun_chr_ioctl+0x80c/0x2870 drivers/net/tun.c:3302\ntun_chr_ioctl+0x2f/0x40 drivers/net/tun.c:3311\nvfs_ioctl fs/ioctl.c:51 [inline]\n__do_sys_ioctl fs/ioctl.c:874 [inline]\n__se_sys_ioctl fs/ioctl.c:860 [inline]\n__x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860\ndo_syscall_x64 arch/x86/entry/common.c:50 [inline]\ndo_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80\nentry_SYSCALL_64_after_hwframe+0x44/0xae","modified":"2026-03-15T14:45:41.561341Z","published":"2024-03-04T18:15:07.120Z","related":["SUSE-SU-2024:1320-1","SUSE-SU-2024:1321-1","SUSE-SU-2024:1454-1","SUSE-SU-2024:1465-1","SUSE-SU-2024:1466-1","SUSE-SU-2024:1480-1","SUSE-SU-2024:1489-1","SUSE-SU-2024:1490-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/0c0e566f0387490d16f166808c72e9c772027681"},{"type":"FIX","url":"https://git.kernel.org/stable/c/158b515f703e75e7d68289bf4d98c664e1d632df"},{"type":"FIX","url":"https://git.kernel.org/stable/c/3cb5ae77799e8ed6ec3fec0b6b4cd07f01650cc5"},{"type":"FIX","url":"https://git.kernel.org/stable/c/8eb43d635950e27c29f1e9e49a23b31637f37757"},{"type":"FIX","url":"https://git.kernel.org/stable/c/a01a4e9f5dc93335c716fa4023b1901956e8c904"}],"affected":[{"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"0"},{"fixed":"4.19.280"}]},{"events":[{"introduced":"4.20"},{"fixed":"5.4.240"}]},{"events":[{"introduced":"5.5"},{"fixed":"5.10.136"}]},{"events":[{"introduced":"5.11"},{"fixed":"5.15.12"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc1"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc2"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc3"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc4"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc5"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc6"}]}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47082.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}