{ "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-2021-47435", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47435", "idYear": 2021, "status": "PUBLISHED", "publishedAt": "2024-05-22T06:19:31.562Z", "updatedAt": "2026-05-11T13:54:38.987Z", "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": "dm: fix mempool NULL pointer race when completing IO", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm: fix mempool NULL pointer race when completing IO\n\ndm_io_dec_pending() calls end_io_acct() first and will then dec md\nin-flight pending count. But if a task is swapping DM table at same\ntime this can result in a crash due to mempool->elements being NULL:\n\ntask1 task2\ndo_resume\n ->do_suspend\n ->dm_wait_for_completion\n bio_endio\n\t\t\t\t ->clone_endio\n\t\t\t\t ->dm_io_dec_pending\n\t\t\t\t ->end_io_acct\n\t\t\t\t ->wakeup task1\n ->dm_swap_table\n ->__bind\n ->__bind_mempools\n ->bioset_exit\n ->mempool_exit\n ->free_io\n\n[ 67.330330] Unable to handle kernel NULL pointer dereference at\nvirtual address 0000000000000000\n......\n[ 67.330494] pstate: 80400085 (Nzcv daIf +PAN -UAO)\n[ 67.330510] pc : mempool_free+0x70/0xa0\n[ 67.330515] lr : mempool_free+0x4c/0xa0\n[ 67.330520] sp : ffffff8008013b20\n[ 67.330524] x29: ffffff8008013b20 x28: 0000000000000004\n[ 67.330530] x27: ffffffa8c2ff40a0 x26: 00000000ffff1cc8\n[ 67.330535] x25: 0000000000000000 x24: ffffffdada34c800\n[ 67.330541] x23: 0000000000000000 x22: ffffffdada34c800\n[ 67.330547] x21: 00000000ffff1cc8 x20: ffffffd9a1304d80\n[ 67.330552] x19: ffffffdada34c970 x18: 000000b312625d9c\n[ 67.330558] x17: 00000000002dcfbf x16: 00000000000006dd\n[ 67.330563] x15: 000000000093b41e x14: 0000000000000010\n[ 67.330569] x13: 0000000000007f7a x12: 0000000034155555\n[ 67.330574] x11: 0000000000000001 x10: 0000000000000001\n[ 67.330579] x9 : 0000000000000000 x8 : 0000000000000000\n[ 67.330585] x7 : 0000000000000000 x6 : ffffff80148b5c1a\n[ 67.330590] x5 : ffffff8008013ae0 x4 : 0000000000000001\n[ 67.330596] x3 : ffffff80080139c8 x2 : ffffff801083bab8\n[ 67.330601] x1 : 0000000000000000 x0 : ffffffdada34c970\n[ 67.330609] Call trace:\n[ 67.330616] mempool_free+0x70/0xa0\n[ 67.330627] bio_put+0xf8/0x110\n[ 67.330638] dec_pending+0x13c/0x230\n[ 67.330644] clone_endio+0x90/0x180\n[ 67.330649] bio_endio+0x198/0x1b8\n[ 67.330655] dec_pending+0x190/0x230\n[ 67.330660] clone_endio+0x90/0x180\n[ 67.330665] bio_endio+0x198/0x1b8\n[ 67.330673] blk_update_request+0x214/0x428\n[ 67.330683] scsi_end_request+0x2c/0x300\n[ 67.330688] scsi_io_completion+0xa0/0x710\n[ 67.330695] scsi_finish_command+0xd8/0x110\n[ 67.330700] scsi_softirq_done+0x114/0x148\n[ 67.330708] blk_done_softirq+0x74/0xd0\n[ 67.330716] __do_softirq+0x18c/0x374\n[ 67.330724] irq_exit+0xb4/0xb8\n[ 67.330732] __handle_domain_irq+0x84/0xc0\n[ 67.330737] gic_handle_irq+0x148/0x1b0\n[ 67.330744] el1_irq+0xe8/0x190\n[ 67.330753] lpm_cpuidle_enter+0x4f8/0x538\n[ 67.330759] cpuidle_enter_state+0x1fc/0x398\n[ 67.330764] cpuidle_enter+0x18/0x20\n[ 67.330772] do_idle+0x1b4/0x290\n[ 67.330778] cpu_startup_entry+0x20/0x28\n[ 67.330786] secondary_start_kernel+0x160/0x170\n\nFix this by:\n1) Establishing pointers to 'struct dm_io' members in\ndm_io_dec_pending() so that they may be passed into end_io_acct()\n_after_ free_io() is called.\n2) Moving end_io_acct() after free_io().", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "6a8736d10cb413be95ea443ba40f25c93f4ef9b2", "status": "affected", "versionType": "git", "lessThan": "9fb7cd5c7fef0f1c982e3cd27745a0dec260eaed" }, { "version": "6a8736d10cb413be95ea443ba40f25c93f4ef9b2", "status": "affected", "versionType": "git", "lessThan": "d35aef9c60d310eff3eaddacce301efe877e2b7c" }, { "version": "6a8736d10cb413be95ea443ba40f25c93f4ef9b2", "status": "affected", "versionType": "git", "lessThan": "9e07272cca2ed76f7f6073f4444b1143828c8d87" }, { "version": "6a8736d10cb413be95ea443ba40f25c93f4ef9b2", "status": "affected", "versionType": "git", "lessThan": "ad1393b92e5059218d055bfec8f4946d85ad04c4" }, { "version": "6a8736d10cb413be95ea443ba40f25c93f4ef9b2", "status": "affected", "versionType": "git", "lessThan": "d29c78d3f9c5d2604548c1065bf1ec212728ea61" }, { "version": "6a8736d10cb413be95ea443ba40f25c93f4ef9b2", "status": "affected", "versionType": "git", "lessThan": "6e506f07c5b561d673dd0b0d8f7f420cc48024fb" }, { "version": "6a8736d10cb413be95ea443ba40f25c93f4ef9b2", "status": "affected", "versionType": "git", "lessThan": "d208b89401e073de986dc891037c5a668f5d5d95" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "2.6.37", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "2.6.37" }, { "version": "4.9.313", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.9.*" }, { "version": "4.14.278", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.14.*" }, { "version": "4.19.242", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.19.*" }, { "version": "5.4.193", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.113", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.14.14", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.14.*" }, { "version": "5.15", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }