Linux Kernel up to 5.18.17/5.19.1 ax25 lib/ref_tracker.c dev_tracker allocation of resources

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.18.17/5.19.1 and classified as problematic. The impacted element is the function dev_tracker in the library lib/ref_tracker.c of the component ax25. Such manipulation leads to allocation of resources. This vulnerability is referenced as CVE-2022-50163. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.18.17/5.19.1. It has been rated as problematic. Affected by this issue is the function dev_tracker in the library lib/ref_tracker.c of the component ax25. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ax25: fix incorrect dev_tracker usage While investigating a separate rose issue [1], and enabling CONFIG_NET_DEV_REFCNT_TRACKER=y, Bernard reported an orthogonal ax25 issue [2] An ax25_dev can be used by one (or many) struct ax25_cb. We thus need different dev_tracker, one per struct ax25_cb. After this patch is applied, we are able to focus on rose. [1] https://lore.kernel.org/netdev/[email protected]/ [2] [ 205.798723] reference already released. [ 205.798732] allocated in: [ 205.798734] ax25_bind+0x1a2/0x230 [ax25] [ 205.798747] __sys_bind+0xea/0x110 [ 205.798753] __x64_sys_bind+0x18/0x20 [ 205.798758] do_syscall_64+0x5c/0x80 [ 205.798763] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 205.798768] freed in: [ 205.798770] ax25_release+0x115/0x370 [ax25] [ 205.798778] __sock_release+0x42/0xb0 [ 205.798782] sock_close+0x15/0x20 [ 205.798785] __fput+0x9f/0x260 [ 205.798789] ____fput+0xe/0x10 [ 205.798792] task_work_run+0x64/0xa0 [ 205.798798] exit_to_user_mode_prepare+0x18b/0x190 [ 205.798804] syscall_exit_to_user_mode+0x26/0x40 [ 205.798808] do_syscall_64+0x69/0x80 [ 205.798812] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 205.798827] ------------[ cut here ]------------ [ 205.798829] WARNING: CPU: 2 PID: 2605 at lib/ref_tracker.c:136 ref_tracker_free.cold+0x60/0x81 [ 205.798837] Modules linked in: rose netrom mkiss ax25 rfcomm cmac algif_hash algif_skcipher af_alg bnep snd_hda_codec_hdmi nls_iso8859_1 i915 rtw88_8821ce rtw88_8821c x86_pkg_temp_thermal rtw88_pci intel_powerclamp rtw88_core snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio coretemp snd_hda_intel kvm_intel snd_intel_dspcfg mac80211 snd_hda_codec kvm i2c_algo_bit drm_buddy drm_dp_helper btusb drm_kms_helper snd_hwdep btrtl snd_hda_core btbcm joydev crct10dif_pclmul btintel crc32_pclmul ghash_clmulni_intel mei_hdcp btmtk intel_rapl_msr aesni_intel bluetooth input_leds snd_pcm crypto_simd syscopyarea processor_thermal_device_pci_legacy sysfillrect cryptd intel_soc_dts_iosf snd_seq sysimgblt ecdh_generic fb_sys_fops rapl libarc4 processor_thermal_device intel_cstate processor_thermal_rfim cec snd_timer ecc snd_seq_device cfg80211 processor_thermal_mbox mei_me processor_thermal_rapl mei rc_core at24 snd intel_pch_thermal intel_rapl_common ttm soundcore int340x_thermal_zone video [ 205.798948] mac_hid acpi_pad sch_fq_codel ipmi_devintf ipmi_msghandler drm msr parport_pc ppdev lp parport ramoops pstore_blk reed_solomon pstore_zone efi_pstore ip_tables x_tables autofs4 hid_generic usbhid hid i2c_i801 i2c_smbus r8169 xhci_pci ahci libahci realtek lpc_ich xhci_pci_renesas [last unloaded: ax25] [ 205.798992] CPU: 2 PID: 2605 Comm: ax25ipd Not tainted 5.18.11-F6BVP #3 [ 205.798996] Hardware name: To be filled by O.E.M. To be filled by O.E.M./CK3, BIOS 5.011 09/16/2020 [ 205.798999] RIP: 0010:ref_tracker_free.cold+0x60/0x81 [ 205.799005] Code: e8 d2 01 9b ff 83 7b 18 00 74 14 48 c7 c7 2f d7 ff 98 e8 10 6e fc ff 8b 7b 18 e8 b8 01 9b ff 4c 89 ee 4c 89 e7 e8 5d fd 07 00 <0f> 0b b8 ea ff ff ff e9 30 05 9b ff 41 0f b6 f7 48 c7 c7 a0 fa 4e [ 205.799008] RSP: 0018:ffffaf5281073958 EFLAGS: 00010286 [ 205.799011] RAX: 0000000080000000 RBX: ffff9a0bd687ebe0 RCX: 0000000000000000 [ 205.799014] RDX: 0000000000000001 RSI: 0000000000000282 RDI: 00000000ffffffff [ 205.799016] RBP: ffffaf5281073a10 R08: 0000000000000003 R09: fffffffffffd5618 [ 205.799019] R10: 0000000000ffff10 R11: 000000000000000f R12: ffff9a0bc53384d0 [ 205.799022] R13: 0000000000000282 R14: 00000000ae000001 R15: 0000000000000001 [ 205.799024] FS: 0000000000000000(0000) GS:ffff9a0d0f300000(0000) knlGS:0000000000000000 [ 205.799028] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 205.799031] CR2: 00007ff6b8311554 CR3: 000000001ac10004 CR4: 00000000001706e0 [ 205.799033] Call Trace: [ 205.799035] <TASK> [ 205.799038] ? ax25_dev_device_down+0xd9/ ---truncated---

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2022-50163 since 06/18/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

Upgrading to version 5.18.18 or 5.19.2 eliminates this vulnerability. Applying the patch d08e3d71e5942f77fbff7f3529ed7fc82fbb3dfa/4294df1374450912b2f64ee3cf575069fc784679/d7c4c9e075f8cc6d88d277bc24e5d99297f03c06 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1350). Once again VulDB remains the best source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Avamar
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.18.0
• 5.18.1
• 5.18.2
• 5.18.3
• 5.18.4
• 5.18.5
• 5.18.6
• 5.18.7
• 5.18.8
• 5.18.9
• 5.18.10
• 5.18.11
• 5.18.12
• 5.18.13
• 5.18.14
• 5.18.15
• 5.18.16
• 5.18.17
• 5.19.0
• 5.19.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

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