Riskcovery

CVE-2022-49626

sfc: fix use after free when disabling sriov

State
Published
Severity
7.8 High
Published
Feb 26, 2025
Updated
May 11, 2026
Reserved
Feb 26, 2025

Read the record on cve.org

Description

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

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCISA-ADP

Weaknesses

Affected Products

ProductVersions
LinuxLinux
  • 3c5eb87605e85146a78de589b5070a37862425db to before 3199e34912d84cdfb8a93a984c5ae5c73fb13e84Affected
  • 3c5eb87605e85146a78de589b5070a37862425db to before c9e75bb22a26e391f189f5a5133dd63dcb57fdaaAffected
  • 3c5eb87605e85146a78de589b5070a37862425db to before 9c854ae512b89229aeee93849e9bd4c115b37909Affected
  • 3c5eb87605e85146a78de589b5070a37862425db to before bcad880865bfb421885364b1f0c7351280fe2b97Affected
  • 3c5eb87605e85146a78de589b5070a37862425db to before c2240500817b3b4b996cdf2a461a3a5679f49b94Affected
  • 3c5eb87605e85146a78de589b5070a37862425db to before 58d93e9d160c0de6d867c7eb4c2206671a351eb1Affected
  • 3c5eb87605e85146a78de589b5070a37862425db to before e435c4aeeaa073091f7f3b7735af2ef5c97d63f2Affected
  • 3c5eb87605e85146a78de589b5070a37862425db to before ebe41da5d47ac0fff877e57bd14c54dccf168827Affected
LinuxLinux
  • 4.2Affected
  • before 4.2Not affected
  • 4.9.324 through 4.9.*Not affected
  • 4.14.289 through 4.14.*Not affected
  • 4.19.253 through 4.19.*Not affected
  • 5.4.207 through 5.4.*Not affected
  • 5.10.132 through 5.10.*Not affected
  • 5.15.56 through 5.15.*Not affected
  • 5.18.13 through 5.18.*Not affected
  • 5.19 and laterNot affected

References

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