In the Linux kernel, the following vulnerability has been resolved:
ax25: Fix netdev refcount issue
The dev_tracker is added to ax25_cb in ax25_bind(). When the ax25 device is detaching, the dev_tracker of ax25_cb should be deallocated in ax25_kill_by_device() instead of the dev_tracker of ax25_dev. The log reported by ref_tracker is shown below:
[ 80.884935] ref_tracker: reference already released. [ 80.885150] ref_tracker: allocated in: [ 80.885349] ax25_dev_device_up+0x105/0x540 [ 80.885730] ax25_device_event+0xa4/0x420 [ 80.885730] notifier_call_chain+0xc9/0x1e0 [ 80.885730] __dev_notify_flags+0x138/0x280 [ 80.885730] dev_change_flags+0xd7/0x180 [ 80.885730] dev_ifsioc+0x6a9/0xa30 [ 80.885730] dev_ioctl+0x4d8/0xd90 [ 80.885730] sock_do_ioctl+0x1c2/0x2d0 [ 80.885730] sock_ioctl+0x38b/0x4f0 [ 80.885730] __se_sys_ioctl+0xad/0xf0 [ 80.885730] do_syscall_64+0xc4/0x1b0 [ 80.885730] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 80.885730] ref_tracker: freed in: [ 80.885730] ax25_device_event+0x272/0x420 [ 80.885730] notifier_call_chain+0xc9/0x1e0 [ 80.885730] dev_close_many+0x272/0x370 [ 80.885730] unregister_netdevice_many_notify+0x3b5/0x1180 [ 80.885730] unregister_netdev+0xcf/0x120 [ 80.885730] sixpack_close+0x11f/0x1b0 [ 80.885730] tty_ldisc_kill+0xcb/0x190 [ 80.885730] tty_ldisc_hangup+0x338/0x3d0 [ 80.885730] __tty_hangup+0x504/0x740 [ 80.885730] tty_release+0x46e/0xd80 [ 80.885730] __fput+0x37f/0x770 [ 80.885730] __x64_sys_close+0x7b/0xb0 [ 80.885730] do_syscall_64+0xc4/0x1b0 [ 80.885730] entry_SYSCALL_64_after_hwframe+0x67/0x6f [ 80.893739] ------------[ cut here ]------------ [ 80.894030] WARNING: CPU: 2 PID: 140 at lib/ref_tracker.c:255 ref_tracker_free+0x47b/0x6b0 [ 80.894297] Modules linked in: [ 80.894929] CPU: 2 PID: 140 Comm: ax25_conn_rel_6 Not tainted 6.9.0-rc4-g8cd26fd90c1a #11 [ 80.895190] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qem4 [ 80.895514] RIP: 0010:ref_tracker_free+0x47b/0x6b0 [ 80.895808] Code: 83 c5 18 4c 89 eb 48 c1 eb 03 8a 04 13 84 c0 0f 85 df 01 00 00 41 83 7d 00 00 75 4b 4c 89 ff 9 [ 80.896171] RSP: 0018:ffff888009edf8c0 EFLAGS: 00000286 [ 80.896339] RAX: 1ffff1100141ac00 RBX: 1ffff1100149463b RCX: dffffc0000000000 [ 80.896502] RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffff88800a0d6518 [ 80.896925] RBP: ffff888009edf9b0 R08: ffff88806d3288d3 R09: 1ffff1100da6511a [ 80.897212] R10: dffffc0000000000 R11: ffffed100da6511b R12: ffff88800a4a31d4 [ 80.897859] R13: ffff88800a4a31d8 R14: dffffc0000000000 R15: ffff88800a0d6518 [ 80.898279] FS: 00007fd88b7fe700(0000) GS:ffff88806d300000(0000) knlGS:0000000000000000 [ 80.899436] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 80.900181] CR2: 00007fd88c001d48 CR3: 000000000993e000 CR4: 00000000000006f0 ... [ 80.935774] ref_tracker: sp%d@000000000bb9df3d has 1/1 users at [ 80.935774] ax25_bind+0x424/0x4e0 [ 80.935774] __sys_bind+0x1d9/0x270 [ 80.935774] __x64_sys_bind+0x75/0x80 [ 80.935774] do_syscall_64+0xc4/0x1b0 [ 80.935774] entry_SYSCALL_64_after_hwframe+0x67/0x6f
Change ax25_dev->dev_tracker to the dev_tracker of ax25_cb in order to mitigate the bug.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Jul 30, 2024 | May 20, 2024 |
| Suse | — | Upgrade kernel-zfcpdumpUpgrade kernel-rt_debug-develUpgrade dlm-kmp-azureUpgrade dtb-amdUpgrade kernel-rt_debug-livepatch-develUpgrade dtb-broadcomUpgrade reiserfs-kmp-rtUpgrade ocfs2-kmp-azureUpgrade dtb-apmUpgrade kernel-default-baseUpgrade kernel-develUpgrade dtb-allwinnerUpgrade dtb-lgUpgrade dlm-kmp-defaultUpgrade kernel-devel-rtUpgrade dtb-freescaleUpgrade kernel-default-develUpgrade ocfs2-kmp-defaultUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-rt_debugUpgrade kselftests-kmp-rtUpgrade dtb-caviumUpgrade kernel-64kbUpgrade kernel-docs-htmlUpgrade dtb-amazonUpgrade gfs2-kmp-defaultUpgrade dtb-socionextUpgrade kernel-kvmsmall-develUpgrade dtb-marvellUpgrade ocfs2-kmp-64kbUpgrade kernel-symsUpgrade cluster-md-kmp-azureUpgrade kselftests-kmp-defaultUpgrade reiserfs-kmp-defaultUpgrade ocfs2-kmp-rtUpgrade reiserfs-kmp-64kbUpgrade kernel-source-azureUpgrade gfs2-kmp-azureUpgrade dtb-renesasUpgrade kernel-64kb-optionalUpgrade kernel-default-livepatch-develUpgrade kernel-64kb-extraUpgrade gfs2-kmp-64kbUpgrade kernel-docsUpgrade kernel-64kb-develUpgrade dtb-appleUpgrade kernel-azure-extraUpgrade dlm-kmp-rtUpgrade kernel-default-livepatchUpgrade dtb-hisiliconUpgrade dtb-xilinxUpgrade kernel-64kb-livepatch-develUpgrade kernel-debug-develUpgrade kernel-debugUpgrade kernel-sourceUpgrade kernel-rt-optionalUpgrade kernel-azure-livepatch-develUpgrade dtb-alteraUpgrade kernel-rt_debug-vdsoUpgrade kernel-rtUpgrade kernel-default-base-rebuildUpgrade dtb-nvidiaUpgrade dtb-armUpgrade kernel-rt-vdsoUpgrade kselftests-kmp-azureUpgrade cluster-md-kmp-defaultUpgrade cluster-md-kmp-64kbUpgrade kernel-default-vdsoUpgrade kernel-syms-rtUpgrade kernel-default-extraUpgrade kernel-macrosUpgrade dtb-sprdUpgrade cluster-md-kmp-rtUpgrade kernel-source-rtUpgrade kernel-defaultUpgrade dtb-qcomUpgrade kernel-azureUpgrade kernel-kvmsmall-vdsoUpgrade kernel-rt-develUpgrade kernel-devel-azureUpgrade dlm-kmp-64kbUpgrade kernel-source-vanillaUpgrade dtb-amlogicUpgrade dtb-exynosUpgrade kselftests-kmp-64kbUpgrade dtb-mediatekUpgrade kernel-azure-vdsoUpgrade kernel-syms-azureUpgrade kernel-azure-optionalUpgrade dtb-rockchipUpgrade kernel-default-optionalUpgrade reiserfs-kmp-azureUpgrade kernel-rt-livepatch-develUpgrade gfs2-kmp-rtUpgrade kernel-rt-livepatchUpgrade kernel-obs-buildUpgrade kernel-rt-extraUpgrade kernel-azure-develUpgrade kernel-kvmsmallUpgrade kernel-obs-qaUpgrade kernel-debug-vdsoUpgrade kernel-debug-livepatch-devel | Jun 24, 2024 | May 20, 2024 |
| Ubuntu | — | Upgrade linux-image-6.8.0-40-genericUpgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-1012-azure-fdeUpgrade linux-image-genericUpgrade linux-image-6.8.0-1010-oracle-64kUpgrade linux-image-6.8.0-1008-gkeUpgrade linux-image-6.8.0-1009-raspiUpgrade linux-image-oem-24.04Upgrade linux-image-nvidia-6.8Upgrade linux-image-gkeUpgrade linux-image-6.8.0-1010-oracleUpgrade linux-image-6.8.0-40-lowlatencyUpgrade linux-image-oracleUpgrade linux-image-lowlatency-64kUpgrade linux-image-6.8.0-1011-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-1012-azureUpgrade linux-image-virtualUpgrade linux-image-generic-64kUpgrade linux-image-azure-fdeUpgrade linux-image-oem-24.04aUpgrade linux-image-nvidiaUpgrade linux-image-6.8.0-1012-gcpUpgrade linux-image-6.8.0-40-generic-64kUpgrade linux-image-nvidia-64kUpgrade linux-image-lowlatencyUpgrade linux-image-6.8.0-1011-nvidia-64kUpgrade linux-image-6.8.0-1010-oemUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-awsUpgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-oracle-64kUpgrade linux-image-kvmUpgrade linux-image-ibmUpgrade linux-image-6.8.0-1011-nvidia-lowlatencyUpgrade linux-image-generic-lpaeUpgrade linux-image-nvidia-64k-6.8Upgrade linux-image-nvidia-lowlatencyUpgrade linux-image-6.8.0-1013-awsUpgrade linux-image-gcpUpgrade linux-image-azureUpgrade linux-image-ibm-lts-24.04Upgrade linux-image-6.8.0-1010-ibmUpgrade linux-image-generic-hwe-24.04Upgrade linux-image-6.8.0-1011-nvidiaUpgrade linux-image-raspiUpgrade linux-image-ibm-classicUpgrade linux-image-6.8.0-40-lowlatency-64k | Aug 9, 2024 | May 20, 2024 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 10, 2025 | May 20, 2024 |
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