{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2021-47379", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47379", "idYear": 2021, "status": "PUBLISHED", "publishedAt": "2024-05-21T15:03:41.677Z", "updatedAt": "2026-05-23T15:19:51.664Z", "importedAt": "2026-10-24T01:56:36.661Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd\n\nKASAN reports a use-after-free report when doing fuzz test:\n\n[693354.104835] ==================================================================\n[693354.105094] BUG: KASAN: use-after-free in bfq_io_set_weight_legacy+0xd3/0x160\n[693354.105336] Read of size 4 at addr ffff888be0a35664 by task sh/1453338\n\n[693354.105607] CPU: 41 PID: 1453338 Comm: sh Kdump: loaded Not tainted 4.18.0-147\n[693354.105610] Hardware name: Huawei 2288H V5/BC11SPSCB0, BIOS 0.81 07/02/2018\n[693354.105612] Call Trace:\n[693354.105621] dump_stack+0xf1/0x19b\n[693354.105626] ? show_regs_print_info+0x5/0x5\n[693354.105634] ? printk+0x9c/0xc3\n[693354.105638] ? cpumask_weight+0x1f/0x1f\n[693354.105648] print_address_description+0x70/0x360\n[693354.105654] kasan_report+0x1b2/0x330\n[693354.105659] ? bfq_io_set_weight_legacy+0xd3/0x160\n[693354.105665] ? bfq_io_set_weight_legacy+0xd3/0x160\n[693354.105670] bfq_io_set_weight_legacy+0xd3/0x160\n[693354.105675] ? bfq_cpd_init+0x20/0x20\n[693354.105683] cgroup_file_write+0x3aa/0x510\n[693354.105693] ? ___slab_alloc+0x507/0x540\n[693354.105698] ? cgroup_file_poll+0x60/0x60\n[693354.105702] ? 0xffffffff89600000\n[693354.105708] ? usercopy_abort+0x90/0x90\n[693354.105716] ? mutex_lock+0xef/0x180\n[693354.105726] kernfs_fop_write+0x1ab/0x280\n[693354.105732] ? cgroup_file_poll+0x60/0x60\n[693354.105738] vfs_write+0xe7/0x230\n[693354.105744] ksys_write+0xb0/0x140\n[693354.105749] ? __ia32_sys_read+0x50/0x50\n[693354.105760] do_syscall_64+0x112/0x370\n[693354.105766] ? syscall_return_slowpath+0x260/0x260\n[693354.105772] ? do_page_fault+0x9b/0x270\n[693354.105779] ? prepare_exit_to_usermode+0xf9/0x1a0\n[693354.105784] ? enter_from_user_mode+0x30/0x30\n[693354.105793] entry_SYSCALL_64_after_hwframe+0x65/0xca\n\n[693354.105875] Allocated by task 1453337:\n[693354.106001] kasan_kmalloc+0xa0/0xd0\n[693354.106006] kmem_cache_alloc_node_trace+0x108/0x220\n[693354.106010] bfq_pd_alloc+0x96/0x120\n[693354.106015] blkcg_activate_policy+0x1b7/0x2b0\n[693354.106020] bfq_create_group_hierarchy+0x1e/0x80\n[693354.106026] bfq_init_queue+0x678/0x8c0\n[693354.106031] blk_mq_init_sched+0x1f8/0x460\n[693354.106037] elevator_switch_mq+0xe1/0x240\n[693354.106041] elevator_switch+0x25/0x40\n[693354.106045] elv_iosched_store+0x1a1/0x230\n[693354.106049] queue_attr_store+0x78/0xb0\n[693354.106053] kernfs_fop_write+0x1ab/0x280\n[693354.106056] vfs_write+0xe7/0x230\n[693354.106060] ksys_write+0xb0/0x140\n[693354.106064] do_syscall_64+0x112/0x370\n[693354.106069] entry_SYSCALL_64_after_hwframe+0x65/0xca\n\n[693354.106114] Freed by task 1453336:\n[693354.106225] __kasan_slab_free+0x130/0x180\n[693354.106229] kfree+0x90/0x1b0\n[693354.106233] blkcg_deactivate_policy+0x12c/0x220\n[693354.106238] bfq_exit_queue+0xf5/0x110\n[693354.106241] blk_mq_exit_sched+0x104/0x130\n[693354.106245] __elevator_exit+0x45/0x60\n[693354.106249] elevator_switch_mq+0xd6/0x240\n[693354.106253] elevator_switch+0x25/0x40\n[693354.106257] elv_iosched_store+0x1a1/0x230\n[693354.106261] queue_attr_store+0x78/0xb0\n[693354.106264] kernfs_fop_write+0x1ab/0x280\n[693354.106268] vfs_write+0xe7/0x230\n[693354.106271] ksys_write+0xb0/0x140\n[693354.106275] do_syscall_64+0x112/0x370\n[693354.106280] entry_SYSCALL_64_after_hwframe+0x65/0xca\n\n[693354.106329] The buggy address belongs to the object at ffff888be0a35580\n which belongs to the cache kmalloc-1k of size 1024\n[693354.106736] The buggy address is located 228 bytes inside of\n 1024-byte region [ffff888be0a35580, ffff888be0a35980)\n[693354.107114] The buggy address belongs to the page:\n[693354.107273] page:ffffea002f828c00 count:1 mapcount:0 mapping:ffff888107c17080 index:0x0 compound_mapcount: 0\n[693354.107606] flags: 0x17ffffc0008100(slab|head)\n[693354.107760] raw: 0017ffffc0008100 ffffea002fcbc808 ffffea0030bd3a08 ffff888107c17080\n[693354.108020] r\n---truncated---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "946b81da114b8ba5c74bb01e57c0c6eca2bdc801", "status": "affected", "versionType": "git", "lessThan": "d12ddd843f1877de1f7dd2aeea4907cf9ff3ac08" }, { "version": "946b81da114b8ba5c74bb01e57c0c6eca2bdc801", "status": "affected", "versionType": "git", "lessThan": "f58d305887ad7b24986d58e881f6806bb81b2bdf" }, { "version": "946b81da114b8ba5c74bb01e57c0c6eca2bdc801", "status": "affected", "versionType": "git", "lessThan": "7c2c69e010431b0157c9454adcdd2305809bf9fb" }, { "version": "946b81da114b8ba5c74bb01e57c0c6eca2bdc801", "status": "affected", "versionType": "git", "lessThan": "858560b27645e7e97aca37ee8f232cccd658fbd2" }, { "version": "9d5e2d69705fed4ab527f5a283b90ae602f4e0fd", "status": "affected", "versionType": "git" }, { "version": "3ca6e949b751fa3dfbf475ce635364cef543738b", "status": "affected", "versionType": "git" }, { "version": "4.14.51", "status": "affected", "versionType": "semver", "lessThan": "4.15" }, { "version": "4.16.17", "status": "affected", "versionType": "semver", "lessThan": "4.17" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.17", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.17" }, { "version": "5.4.150", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.70", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.14.9", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.14.*" }, { "version": "5.15", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }