CVE-2025-21883
HighIn the Linux kernel, the following vulnerability has been resolved: ice: Fix deinitializing VF in error path If ice_ena_vfs() fails after calling ice_create_vf_entries(), it frees all VFs without removing them from snapshot PF-VF mailbox list, leading to list corruption. Reproducer: devlink dev eswitch set $PF1_PCI mode switchdev ip l s $PF1 up ip l s $PF1 promisc on sleep 1 echo 1 > /sys/class/net/$PF1/device/sriov_numvfs sleep 1 echo 1 > /sys/class/net/$PF1/device/sriov_numvfs Trace (minimized): list_add corruption. next->prev should be prev (ffff8882e241c6f0), but was 0000000000000000. (next=ffff888455da1330). kernel BUG at lib/list_debug.c:29! RIP: 0010:__list_add_valid_or_report+0xa6/0x100 ice_mbx_init_vf_info+0xa7/0x180 [ice] ice_initialize_vf_entry+0x1fa/0x250 [ice] ice_sriov_configure+0x8d7/0x1520 [ice] ? __percpu_ref_switch_mode+0x1b1/0x5d0 ? __pfx_ice_sriov_configure+0x10/0x10 [ice] Sometimes a KASAN report can be seen instead with a similar stack trace: BUG: KASAN: use-after-free in __list_add_valid_or_report+0xf1/0x100 VFs are added to this list in ice_mbx_init_vf_info(), but only removed in ice_free_vfs(). Move the removing to ice_free_vf_entries(), which is also being called in other places where VFs are being removed (including ice_free_vfs() itself).
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2025-21883 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
Affected versions
Linux kernel versions
6.4
and later are affected. Fixed in
6.6.81,
6.12.18,
6.13.6,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21883 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/34393fd78d7183a007eaf0090966ebedcc29bd57
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PatchKernel patch commithttps://git.kernel.org/stable/c/3c01102bec9592928e6b155da41cfcd5d25a2066
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PatchKernel patch commithttps://git.kernel.org/stable/c/79990cf5e7aded76d0c092c9f5ed31eb1c75e02c
Frequently asked questions
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What is CVE-2025-21883?
CVE-2025-21883 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 6.4 onward and has been patched in 6.6.81, 6.12.18, 6.13.6 and others. CVE-2025-21883 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-2025-21883?
CVE-2025-21883 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2025-21883?
Yes — CVE-2025-21883 has been patched. Fixed versions include 6.6.81, 6.12.18, 6.13.6 and others. If you are running Linux kernel 6.4 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21883 actively exploited?
No — CVE-2025-21883 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 Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →