{"uuid": "809e9cc9-2331-4334-a353-56bc548145ad", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2024-39476", "type": "seen", "source": "https://t.me/cvedetector/83", "content": "{\n  \"Source\": \"CVE FEED\",\n  \"Title\": \"CVE-2024-39476 - In the Linux kernel, the following vulnerability h\", \n  \"Content\": \"CVE ID : CVE-2024-39476 \nPublished : July 5, 2024, 7:15 a.m. | 17\u00a0minutes ago \nDescription : In the Linux kernel, the following vulnerability has been resolved: \n \nmd/raid5: fix deadlock that raid5d() wait for itself to clear MD_SB_CHANGE_PENDING \n \nXiao reported that lvm2 test lvconvert-raid-takeover.sh can hang with \nsmall possibility, the root cause is exactly the same as commit \nbed9e27baf52 (\"Revert \"md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d\"\") \n \nHowever, Dan reported another hang after that, and junxiao investigated \nthe problem and found out that this is caused by plugged bio can't issue \nfrom raid5d(). \n \nCurrent implementation in raid5d() has a weird dependence: \n \n1) md_check_recovery() from raid5d() must hold 'reconfig_mutex' to clear \n   MD_SB_CHANGE_PENDING; \n2) raid5d() handles IO in a deadloop, until all IO are issued; \n3) IO from raid5d() must wait for MD_SB_CHANGE_PENDING to be cleared; \n \nThis behaviour is introduce before v2.6, and for consequence, if other \ncontext hold 'reconfig_mutex', and md_check_recovery() can't update \nsuper_block, then raid5d() will waste one cpu 100% by the deadloop, until \n'reconfig_mutex' is released. \n \nRefer to the implementation from raid1 and raid10, fix this problem by \nskipping issue IO if MD_SB_CHANGE_PENDING is still set after \nmd_check_recovery(), daemon thread will be woken up when 'reconfig_mutex' \nis released. Meanwhile, the hang problem will be fixed as well. \nSeverity: 0.0 | NA \nVisit the link for more details, such as CVSS details, affected products, timeline, and more...\",\n  \"Detection Date\": \"05 Jul 2024\",\n  \"Type\": \"Vulnerability\"\n}\n\ud83d\udd39 t.me/cvedetector \ud83d\udd39", "creation_timestamp": "2024-07-05T09:34:06.000000Z"}