{"uuid": "10208449-d46e-411c-ad79-29f7f96d2856", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "2a075640-a300-48a4-bb44-bc6130783b9b", "vulnerability": "CVE-2022-49296", "type": "seen", "source": "https://t.me/DarkWebInformer_CVEAlerts/5421", "content": "\ud83d\udd17 DarkWebInformer.com - Cyber Threat Intelligence\n\ud83d\udccc CVE ID: CVE-2022-49296\n\ud83d\udd25 CVSS Score: N/A\n\ud83d\udd39 Description: In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix possible deadlock when holding Fwb to get inline_data\n\n1, mount with wsync.\n2, create a file with O_RDWR, and the request was sent to mds.0:\n\n   ceph_atomic_open()-->\n     ceph_mdsc_do_request(openc)\n     finish_open(file, dentry, ceph_open)-->\n       ceph_open()-->\n         ceph_init_file()-->\n           ceph_init_file_info()-->\n             ceph_uninline_data()-->\n             {\n               ...\n               if (inline_version == 1 || /* initial version, no data */\n                   inline_version == CEPH_INLINE_NONE)\n                     goto out_unlock;\n               ...\n             }\n\nThe inline_version will be 1, which is the initial version for the\nnew create file. And here the ci->i_inline_version will keep with 1,\nit's buggy.\n\n3, buffer write to the file immediately:\n\n   ceph_write_iter()-->\n     ceph_get_caps(file, need=Fw, want=Fb, ...);\n     generic_perform_write()-->\n       a_ops->write_begin()-->\n         ceph_write_begin()-->\n           netfs_write_begin()-->\n             netfs_begin_read()-->\n               netfs_rreq_submit_slice()-->\n                 netfs_read_from_server()-->\n                   rreq->netfs_ops->issue_read()-->\n                     ceph_netfs_issue_read()-->\n                     {\n                       ...\n                       if (ci->i_inline_version != CEPH_INLINE_NONE &&\n                           ceph_netfs_issue_op_inline(subreq))\n                         return;\n                       ...\n                     }\n     ceph_put_cap_refs(ci, Fwb);\n\nThe ceph_netfs_issue_op_inline() will send a getattr(Fsr) request to\nmds.1.\n\n4, then the mds.1 will request the rd lock for CInode::filelock from\nthe auth mds.0, the mds.0 will do the CInode::filelock state transation\nfrom excl --> sync, but it need to revoke the Fxwb caps back from the\nclients.\n\nWhile the kernel client has aleady held the Fwb caps and waiting for\nthe getattr(Fsr).\n\nIt's deadlock!\n\nURL: https://tracker.ceph.com/issues/55377\n\ud83d\udccf Published: 2025-02-26T02:01:26.131Z\n\ud83d\udccf Modified: 2025-02-26T02:01:26.131Z\n\ud83d\udd17 References:\n1. https://git.kernel.org/stable/c/292b7a7275ce535a1abfa4dd0b2e586162aaae1e\n2. https://git.kernel.org/stable/c/825978fd6a0defc3c29d8a38b6cea76a0938d21e", "creation_timestamp": "2025-02-26T02:23:18.000000Z"}