{ "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-2026-72420", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-72420", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-08-15T05:56:39.802Z", "updatedAt": "2026-10-21T12:44:52.798Z", "importedAt": "2026-10-24T01:58:25.636Z", "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": "md/raid5: avoid R5_Overlap races while breaking stripe batches", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd/raid5: avoid R5_Overlap races while breaking stripe batches\n\nKCSAN report a race in break_stripe_batch_list() vs. raid5_make_request()\non sh->dev[i].flags (plain word write vs. atomic bit op)..\n\nand .. one possible scenario is:\n\nCPU1 CPU2\nbreak_stripe_batch_list(sh1)\n-> handle sh2\n-> lock(sh2)\n-> sh2->batch_head = NULL\n-> unlock(sh2)\n-> test_and_clear_bit(R5_Overlap, sh2->dev[i].flags)\n-> wake_up_bit(sh2->dev[i].flags)\n raid5_make_request()\n -> add_all_stripe_bios(sh2)\n -> lock(sh2)\n -> stripe_bio_overlaps(sh2) returns true\n\t\t\t\t batch_head is NULL, so new bio overlap\n\t\t\t\t exist bio on sh2 -> true\n -> set_bit(R5_Overlap, sh2->dev[i].flags)\n -> unlock(sh2)\n -> wait_on_bit(sh2->dev[i].flags)\n-> sh2->dev[i].flags = sh1->dev[i].flags & ~R5_Overlap\n\nNo wait_up_bit(), CPU2 could be wait_on_bit() forever...\n\nFix by :\n- Expand the protect zone.\n- Use batch_head's device flag's snaphot when no held head_sh->stripe_lock.\n- Move sh/head_sh->batch_head = NULL to the end of protected zone , and ,\n any concurrent add_all_stripe_bios() grabs sh->stripe_lock now either:\n\t- see batch_head != null, and , is rejected by stripe_bio_overlaps()\n\t under the lock (no R5_Overlap wait ) , or ,\n\t- sees batch_head == NULL, only after dev[i].flags has already been\n\t set and the prior R5_Overlap waiters worken.\n\nKCSAN report:\n================================================\n BUG: KCSAN: data-race in break_stripe_batch_list / raid5_make_request\n\n write (marked) to 0xffff8e89c8117548 of 8 bytes by task 4042 on cpu 0:\n raid5_make_request+0xea0/0x2930\n md_handle_request+0x4a2/0xa40\n md_submit_bio+0x109/0x1a0\n __submit_bio+0x2ec/0x390\n submit_bio_noacct_nocheck+0x457/0x710\n submit_bio_noacct+0x2a7/0xc20\n submit_bio+0x56/0x250\n blkdev_direct_IO+0x54c/0xda0\n blkdev_write_iter+0x38f/0x570\n aio_write+0x22b/0x490\n io_submit_one+0xa51/0xf70\n __x64_sys_io_submit+0xf7/0x220\n x64_sys_call+0x1907/0x1c60\n do_syscall_64+0x130/0x570\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n read to 0xffff8e89c8117548 of 8 bytes by task 4010 on cpu 5:\n break_stripe_batch_list+0x249/0x480\n handle_stripe_clean_event+0x720/0x9b0\n handle_stripe+0x32fb/0x4500\n handle_active_stripes.isra.0+0x6e0/0xa50\n raid5d+0x7e0/0xba0\n md_thread+0x15a/0x2d0\n kthread+0x1e3/0x220\n ret_from_fork+0x37a/0x410\n ret_from_fork_asm+0x1a/0x30\n\n value changed: 0x0000000000000019 -> 0x0000000000000099 --> R5_Overlap", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "fb642b92c267beeefd352af9bc461eac93a7552c", "status": "affected", "versionType": "git", "lessThan": "158a5480d51969adeb727ff20c6fa96f063e9f9e" }, { "version": "fb642b92c267beeefd352af9bc461eac93a7552c", "status": "affected", "versionType": "git", "lessThan": "8031b0d02bd221a5f9add4357e291fc2a527b83a" }, { "version": "fb642b92c267beeefd352af9bc461eac93a7552c", "status": "affected", "versionType": "git", "lessThan": "4d919c9b770996365806b6c8d701912d52baa306" }, { "version": "fb642b92c267beeefd352af9bc461eac93a7552c", "status": "affected", "versionType": "git", "lessThan": "d684b72dfbd320623ccaab0779aa841190488e7c" }, { "version": "fb642b92c267beeefd352af9bc461eac93a7552c", "status": "affected", "versionType": "git", "lessThan": "55b77337bdd088c77461588e5ec094421b89911b" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.1", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.1" }, { "version": "6.6.160", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.97", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.40", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.1.5", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.1.*" }, { "version": "7.2", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }