CVE-2022-48969
MediumIn the Linux kernel, the following vulnerability has been resolved: xen-netfront: Fix NULL sring after live migration A NAPI is setup for each network sring to poll data to kernel The sring with source host is destroyed before live migration and new sring with target host is setup after live migration. The NAPI for the old sring is not deleted until setup new sring with target host after migration. With busy_poll/busy_read enabled, the NAPI can be polled before got deleted when resume VM. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: xennet_poll+0xae/0xd20 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Call Trace: finish_task_switch+0x71/0x230 timerqueue_del+0x1d/0x40 hrtimer_try_to_cancel+0xb5/0x110 xennet_alloc_rx_buffers+0x2a0/0x2a0 napi_busy_loop+0xdb/0x270 sock_poll+0x87/0x90 do_sys_poll+0x26f/0x580 tracing_map_insert+0x1d4/0x2f0 event_hist_trigger+0x14a/0x260 finish_task_switch+0x71/0x230 __schedule+0x256/0x890 recalc_sigpending+0x1b/0x50 xen_sched_clock+0x15/0x20 __rb_reserve_next+0x12d/0x140 ring_buffer_lock_reserve+0x123/0x3d0 event_triggers_call+0x87/0xb0 trace_event_buffer_commit+0x1c4/0x210 xen_clocksource_get_cycles+0x15/0x20 ktime_get_ts64+0x51/0xf0 SyS_ppoll+0x160/0x1a0 SyS_ppoll+0x160/0x1a0 do_syscall_64+0x73/0x130 entry_SYSCALL_64_after_hwframe+0x41/0xa6 ... RIP: xennet_poll+0xae/0xd20 RSP: ffffb4f041933900 CR2: 0000000000000008 ---[ end trace f8601785b354351c ]--- xen frontend should remove the NAPIs for the old srings before live migration as the bond srings are destroyed There is a tiny window between the srings are set to NULL and the NAPIs are disabled, It is safe as the NAPI threads are still frozen at that time
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-476CVE-2022-48969 is a NULL Pointer Dereference vulnerability
What is NULL Pointer Dereference?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE
Affected versions
Linux kernel versions
2.6.24
and later are affected. Fixed in
4.19.269,
5.4.227,
5.10.159,
5.15.83,
6.0.13,
6.1
and their respective stable series.
References
The following references provide additional information about CVE-2022-48969 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/99859947517e446058ad7243ee81d2f9801fa3dd
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PatchKernel patch commithttps://git.kernel.org/stable/c/d50b7914fae04d840ce36491d22133070b18cca9
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PatchKernel patch commithttps://git.kernel.org/stable/c/e6860c889f4ad50b6ab696f5ea154295d72cf27a
Frequently asked questions
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What is CVE-2022-48969?
CVE-2022-48969 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 2.6.24 onward and has been patched in 4.19.269, 5.4.227, 5.10.159 and others. CVE-2022-48969 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2022-48969?
CVE-2022-48969 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2022-48969?
Yes — CVE-2022-48969 has been patched. Fixed versions include 4.19.269, 5.4.227, 5.10.159 and others. If you are running Linux kernel 2.6.24 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-48969 actively exploited?
No — CVE-2022-48969 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is NULL Pointer Dereference (CWE-476)?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →