{"id":"CVE-2022-49626","summary":"sfc: fix use after free when disabling sriov","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsfc: fix use after free when disabling sriov\n\nUse after free is detected by kfence when disabling sriov. What was read\nafter being freed was vf-\u003epci_dev: it was freed from pci_disable_sriov\nand later read in efx_ef10_sriov_free_vf_vports, called from\nefx_ef10_sriov_free_vf_vswitching.\n\nSet the pointer to NULL at release time to not trying to read it later.\n\nReproducer and dmesg log (note that kfence doesn't detect it every time):\n$ echo 1 \u003e /sys/class/net/enp65s0f0np0/device/sriov_numvfs\n$ echo 0 \u003e /sys/class/net/enp65s0f0np0/device/sriov_numvfs\n\n BUG: KFENCE: use-after-free read in efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc]\n\n Use-after-free read at 0x00000000ff3c1ba5 (in kfence-#224):\n  efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc]\n  efx_ef10_pci_sriov_disable+0x38/0x70 [sfc]\n  efx_pci_sriov_configure+0x24/0x40 [sfc]\n  sriov_numvfs_store+0xfe/0x140\n  kernfs_fop_write_iter+0x11c/0x1b0\n  new_sync_write+0x11f/0x1b0\n  vfs_write+0x1eb/0x280\n  ksys_write+0x5f/0xe0\n  do_syscall_64+0x5c/0x80\n  entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n kfence-#224: 0x00000000edb8ef95-0x00000000671f5ce1, size=2792, cache=kmalloc-4k\n\n allocated by task 6771 on cpu 10 at 3137.860196s:\n  pci_alloc_dev+0x21/0x60\n  pci_iov_add_virtfn+0x2a2/0x320\n  sriov_enable+0x212/0x3e0\n  efx_ef10_sriov_configure+0x67/0x80 [sfc]\n  efx_pci_sriov_configure+0x24/0x40 [sfc]\n  sriov_numvfs_store+0xba/0x140\n  kernfs_fop_write_iter+0x11c/0x1b0\n  new_sync_write+0x11f/0x1b0\n  vfs_write+0x1eb/0x280\n  ksys_write+0x5f/0xe0\n  do_syscall_64+0x5c/0x80\n  entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n freed by task 6771 on cpu 12 at 3170.991309s:\n  device_release+0x34/0x90\n  kobject_cleanup+0x3a/0x130\n  pci_iov_remove_virtfn+0xd9/0x120\n  sriov_disable+0x30/0xe0\n  efx_ef10_pci_sriov_disable+0x57/0x70 [sfc]\n  efx_pci_sriov_configure+0x24/0x40 [sfc]\n  sriov_numvfs_store+0xfe/0x140\n  kernfs_fop_write_iter+0x11c/0x1b0\n  new_sync_write+0x11f/0x1b0\n  vfs_write+0x1eb/0x280\n  ksys_write+0x5f/0xe0\n  do_syscall_64+0x5c/0x80\n  entry_SYSCALL_64_after_hwframe+0x44/0xae","modified":"2026-04-02T08:27:46.065205Z","published":"2025-02-26T02:23:41.274Z","related":["SUSE-SU-2025:0834-1","SUSE-SU-2025:1027-1","SUSE-SU-2025:1176-1","SUSE-SU-2025:1183-1","SUSE-SU-2025:1241-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49626.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3199e34912d84cdfb8a93a984c5ae5c73fb13e84"},{"type":"WEB","url":"https://git.kernel.org/stable/c/58d93e9d160c0de6d867c7eb4c2206671a351eb1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9c854ae512b89229aeee93849e9bd4c115b37909"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bcad880865bfb421885364b1f0c7351280fe2b97"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c2240500817b3b4b996cdf2a461a3a5679f49b94"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c9e75bb22a26e391f189f5a5133dd63dcb57fdaa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e435c4aeeaa073091f7f3b7735af2ef5c97d63f2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ebe41da5d47ac0fff877e57bd14c54dccf168827"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49626.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-49626"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3c5eb87605e85146a78de589b5070a37862425db"},{"fixed":"3199e34912d84cdfb8a93a984c5ae5c73fb13e84"},{"fixed":"c9e75bb22a26e391f189f5a5133dd63dcb57fdaa"},{"fixed":"9c854ae512b89229aeee93849e9bd4c115b37909"},{"fixed":"bcad880865bfb421885364b1f0c7351280fe2b97"},{"fixed":"c2240500817b3b4b996cdf2a461a3a5679f49b94"},{"fixed":"58d93e9d160c0de6d867c7eb4c2206671a351eb1"},{"fixed":"e435c4aeeaa073091f7f3b7735af2ef5c97d63f2"},{"fixed":"ebe41da5d47ac0fff877e57bd14c54dccf168827"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49626.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}