sfc: fix use after free when disabling sriov
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: sfc: fix use after free when disabling sriov Use after free is detected by kfence when disabling sriov. What was read after being freed was vf->pci_dev: it was freed from pci_disable_sriov and later read in efx_ef10_sriov_free_vf_vports, called from efx_ef10_sriov_free_vf_vswitching. Set the pointer to NULL at release time to not trying to read it later. Reproducer and dmesg log (note that kfence doesn't detect it every time): $ echo 1 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs $ echo 0 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs BUG: KFENCE: use-after-free read in efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc] Use-after-free read at 0x00000000ff3c1ba5 (in kfence-#224): efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc] efx_ef10_pci_sriov_disable+0x38/0x70 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xfe/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae kfence-#224: 0x00000000edb8ef95-0x00000000671f5ce1, size=2792, cache=kmalloc-4k allocated by task 6771 on cpu 10 at 3137.860196s: pci_alloc_dev+0x21/0x60 pci_iov_add_virtfn+0x2a2/0x320 sriov_enable+0x212/0x3e0 efx_ef10_sriov_configure+0x67/0x80 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xba/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae freed by task 6771 on cpu 12 at 3170.991309s: device_release+0x34/0x90 kobject_cleanup+0x3a/0x130 pci_iov_remove_virtfn+0xd9/0x120 sriov_disable+0x30/0xe0 efx_ef10_pci_sriov_disable+0x57/0x70 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xfe/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.2 and later | 4.9.324, 4.14.289, 4.19.253, 5.4.207, 5.10.132, 5.15.56, 5.18.13, 5.19 | Patch available | CNA |
- Linux VendorLinux Affected 4.2 and later Fixed in 4.9.324, 4.14.289, 4.19.253, 5.4.207, 5.10.132, 5.15.56, 5.18.13, 5.19 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.2 to before 4.9.324; 4.10 to before 4.14.289; 4.15 to before 4.19.253; 4.20 to before 5.4.207; 5.5 to before 5.10.132; 5.11 to before 5.15.56; 5.16 to before 5.18.13 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.19:rc1:*:*:*:*:*:* | 5.19 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.19:rc2:*:*:*:*:*:* | 5.19 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.19:rc3:*:*:*:*:*:* | 5.19 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.19:rc4:*:*:*:*:*:* | 5.19 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.19:rc5:*:*:*:*:*:* | 5.19 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.19:rc6:*:*:*:*:*:* | 5.19 rc6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.2 to before 4.9.324; 4.10 to before 4.14.289; 4.15 to before 4.19.253; 4.20 to before 5.4.207; 5.5 to before 5.10.132; 5.11 to before 5.15.56; 5.16 to before 5.18.13 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.19:rc1:*:*:*:*:*:* Versions 5.19 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.19:rc2:*:*:*:*:*:* Versions 5.19 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.19:rc3:*:*:*:*:*:* Versions 5.19 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.19:rc4:*:*:*:*:*:* Versions 5.19 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.19:rc5:*:*:*:*:*:* Versions 5.19 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.19:rc6:*:*:*:*:*:* Versions 5.19 rc6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.9.324, 4.14.289, 4.19.253, 5.4.207, 5.10.132, 5.15.56, 5.18.13, 5.19
Red Hat 2 advisories
- RHSA-2022:8267 Released 2022-11-15 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-162.6.1.el9_1
- Red Hat Enterprise Linux AppStream (v. 9) kernel-debug-devel-5.14.0-162.6.1.el9_1, kernel-debug-devel-matched-5.14.0-162.6.1.el9_1, kernel-devel-5.14.0-162.6.1.el9_1 +5
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-5.14.0-162.6.1.el9_1, kernel-5.14.0-162.6.1.el9_1, kernel-abi-stablelists-5.14.0-162.6.1.el9_1 +14
- RHSA-2022:7683 Released 2022-11-08 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-425.3.1.el8
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-425.3.1.el8, kernel-4.18.0-425.3.1.el8, kernel-abi-stablelists-4.18.0-425.3.1.el8 +19
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2022:7683 |
| Red Hat CodeReady Linux Builder (v. 9) | Fixed | RHSA-2022:8267 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2022:8267 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2022:7683 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2022:8267 |
Not affected: 2 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2022-49626
- 2026-10-03 Alias added: GHSA-fv97-qmwg-89pj
References
Patch 8
- https://git.kernel.org/stable/c/3199e34912d84cdfb8a93a984c5ae5c73fb13e84
- https://git.kernel.org/stable/c/c9e75bb22a26e391f189f5a5133dd63dcb57fdaa
- https://git.kernel.org/stable/c/9c854ae512b89229aeee93849e9bd4c115b37909
- https://git.kernel.org/stable/c/bcad880865bfb421885364b1f0c7351280fe2b97
- https://git.kernel.org/stable/c/c2240500817b3b4b996cdf2a461a3a5679f49b94
- https://git.kernel.org/stable/c/58d93e9d160c0de6d867c7eb4c2206671a351eb1
- https://git.kernel.org/stable/c/e435c4aeeaa073091f7f3b7735af2ef5c97d63f2
- https://git.kernel.org/stable/c/ebe41da5d47ac0fff877e57bd14c54dccf168827
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2022-49626 · CVE Program
- CVE-2022-49626 · NVD
- FIRST EPSS
- GHSA-fv97-qmwg-89pj · GitHub Advisory Database · CC BY 4.0
- CVE-2022-49626 · Red Hat security data · CC BY 4.0
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