CVE-2024-36009

ax25: Fix netdev refcount issue

State: Published
Severity: 7.8 High
Published: May 20, 2024
Updated: Aug 5, 2026
Reserved: May 17, 2024

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	feef318c855a361a1eccd880f33e88c460eb63b4 to before 0d14f104027e30720582448706c7d6b43065c851Affected feef318c855a361a1eccd880f33e88c460eb63b4 to before 4fee8fa86a15d7790268eea458b1aec69c695530Affected feef318c855a361a1eccd880f33e88c460eb63b4 to before c42b073d9af4a5329b25b17390c63ab3847f30e8Affected feef318c855a361a1eccd880f33e88c460eb63b4 to before 467324bcfe1a31ec65d0cf4aa59421d6b7a7d52bAffected b8c07f33aa35dacf5444e7053ed9662d1869f536Affected b1e0a6fc7f17500484c402ad1cd018c24dfc14b3Affected 7528d0f2210c3a1154186175516ed37aa970f2b1Affected 57cc15f5fd550316e4104eaf84b90fbc640fd7a5Affected b982492ec3a115e0a136856a1b2dbe32f2d21a0eAffected 4.14.277 to before 4.15Affected 4.19.240 to before 4.20Affected 5.4.190 to before 5.5Affected 5.10.112 to before 5.11Affected 5.15.35 to before 5.16Affected
LinuxLinux	5.17Affected before 5.17Not affected 6.1.90 through 6.1.Not affected 6.6.30 through 6.6.Not affected 6.8.9 through 6.8.*Not affected 6.9 and laterNot affected

Product

Versions

LinuxLinux

feef318c855a361a1eccd880f33e88c460eb63b4 to before 0d14f104027e30720582448706c7d6b43065c851Affected
feef318c855a361a1eccd880f33e88c460eb63b4 to before 4fee8fa86a15d7790268eea458b1aec69c695530Affected
feef318c855a361a1eccd880f33e88c460eb63b4 to before c42b073d9af4a5329b25b17390c63ab3847f30e8Affected
feef318c855a361a1eccd880f33e88c460eb63b4 to before 467324bcfe1a31ec65d0cf4aa59421d6b7a7d52bAffected
b8c07f33aa35dacf5444e7053ed9662d1869f536Affected
b1e0a6fc7f17500484c402ad1cd018c24dfc14b3Affected
7528d0f2210c3a1154186175516ed37aa970f2b1Affected
57cc15f5fd550316e4104eaf84b90fbc640fd7a5Affected
b982492ec3a115e0a136856a1b2dbe32f2d21a0eAffected
4.14.277 to before 4.15Affected
4.19.240 to before 4.20Affected
5.4.190 to before 5.5Affected
5.10.112 to before 5.11Affected
5.15.35 to before 5.16Affected

LinuxLinux

5.17Affected
before 5.17Not affected
6.1.90 through 6.1.*Not affected
6.6.30 through 6.6.*Not affected
6.8.9 through 6.8.*Not affected
6.9 and laterNot affected

References

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