{ "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-2021-46938", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-46938", "idYear": 2021, "status": "PUBLISHED", "publishedAt": "2024-02-27T18:40:26.850Z", "updatedAt": "2026-05-11T13:44:48.604Z", "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 rq: fix double free of blk_mq_tag_set in dev remove after table load fails", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm rq: fix double free of blk_mq_tag_set in dev remove after table load fails\n\nWhen loading a device-mapper table for a request-based mapped device,\nand the allocation/initialization of the blk_mq_tag_set for the device\nfails, a following device remove will cause a double free.\n\nE.g. (dmesg):\n device-mapper: core: Cannot initialize queue for request-based dm-mq mapped device\n device-mapper: ioctl: unable to set up device queue for new table.\n Unable to handle kernel pointer dereference in virtual kernel address space\n Failing address: 0305e098835de000 TEID: 0305e098835de803\n Fault in home space mode while using kernel ASCE.\n AS:000000025efe0007 R3:0000000000000024\n Oops: 0038 ilc:3 [#1] SMP\n Modules linked in: ... lots of modules ...\n Supported: Yes, External\n CPU: 0 PID: 7348 Comm: multipathd Kdump: loaded Tainted: G W X 5.3.18-53-default #1 SLE15-SP3\n Hardware name: IBM 8561 T01 7I2 (LPAR)\n Krnl PSW : 0704e00180000000 000000025e368eca (kfree+0x42/0x330)\n R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3\n Krnl GPRS: 000000000000004a 000000025efe5230 c1773200d779968d 0000000000000000\n 000000025e520270 000000025e8d1b40 0000000000000003 00000007aae10000\n 000000025e5202a2 0000000000000001 c1773200d779968d 0305e098835de640\n 00000007a8170000 000003ff80138650 000000025e5202a2 000003e00396faa8\n Krnl Code: 000000025e368eb8: c4180041e100 lgrl %r1,25eba50b8\n 000000025e368ebe: ecba06b93a55 risbg %r11,%r10,6,185,58\n #000000025e368ec4: e3b010000008 ag %r11,0(%r1)\n >000000025e368eca: e310b0080004 lg %r1,8(%r11)\n 000000025e368ed0: a7110001 tmll %r1,1\n 000000025e368ed4: a7740129 brc 7,25e369126\n 000000025e368ed8: e320b0080004 lg %r2,8(%r11)\n 000000025e368ede: b904001b lgr %r1,%r11\n Call Trace:\n [<000000025e368eca>] kfree+0x42/0x330\n [<000000025e5202a2>] blk_mq_free_tag_set+0x72/0xb8\n [<000003ff801316a8>] dm_mq_cleanup_mapped_device+0x38/0x50 [dm_mod]\n [<000003ff80120082>] free_dev+0x52/0xd0 [dm_mod]\n [<000003ff801233f0>] __dm_destroy+0x150/0x1d0 [dm_mod]\n [<000003ff8012bb9a>] dev_remove+0x162/0x1c0 [dm_mod]\n [<000003ff8012a988>] ctl_ioctl+0x198/0x478 [dm_mod]\n [<000003ff8012ac8a>] dm_ctl_ioctl+0x22/0x38 [dm_mod]\n [<000000025e3b11ee>] ksys_ioctl+0xbe/0xe0\n [<000000025e3b127a>] __s390x_sys_ioctl+0x2a/0x40\n [<000000025e8c15ac>] system_call+0xd8/0x2c8\n Last Breaking-Event-Address:\n [<000000025e52029c>] blk_mq_free_tag_set+0x6c/0xb8\n Kernel panic - not syncing: Fatal exception: panic_on_oops\n\nWhen allocation/initialization of the blk_mq_tag_set fails in\ndm_mq_init_request_queue(), it is uninitialized/freed, but the pointer\nis not reset to NULL; so when dev_remove() later gets into\ndm_mq_cleanup_mapped_device() it sees the pointer and tries to\nuninitialize and free it again.\n\nFix this by setting the pointer to NULL in dm_mq_init_request_queue()\nerror-handling. Also set it to NULL in dm_mq_cleanup_mapped_device().", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "8ae0185255eaf05bd66f4215c81e99bf01140fd9" }, { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "b42c0a33dfdd451d9be62dd5de58c39f2750b6e3" }, { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "772b9f59657665af3b68d24d12b9d172d31f0dfb" }, { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "a992a283c0b77d0a7c2c348add0e6a21fb1dab67" }, { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "1cb02dc76f4c0a2749a02b26469512d6984252e9" }, { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "6086f957416a6e87236c06079fcaba7a3998aeca" }, { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "d757bf4c69cda3c3ab7f775dfabbf5a80e2f6f9d" }, { "version": "1c357a1e86a4227a6b6059f2de118ae47659cebc", "status": "affected", "versionType": "git", "lessThan": "8e947c8f4a5620df77e43c9c75310dc510250166" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.6", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.6" }, { "version": "4.9.269", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.9.*" }, { "version": "4.14.233", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.14.*" }, { "version": "4.19.191", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.19.*" }, { "version": "5.4.118", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.36", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.11.20", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.11.*" }, { "version": "5.12.3", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.12.*" }, { "version": "5.13", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }