{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2021-46938",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "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()."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "1c357a1e86a4",
                                            "version_value": "8ae0185255ea"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "4.6",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "4.6",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "4.9.269",
                                                        "lessThanOrEqual": "4.9.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "4.14.233",
                                                        "lessThanOrEqual": "4.14.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "4.19.191",
                                                        "lessThanOrEqual": "4.19.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.4.118",
                                                        "lessThanOrEqual": "5.4.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.10.36",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.11.20",
                                                        "lessThanOrEqual": "5.11.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.12.3",
                                                        "lessThanOrEqual": "5.12.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.13",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
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                        ]
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        }
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    "references": {
        "reference_data": [
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                "url": "https://git.kernel.org/stable/c/8ae0185255eaf05bd66f4215c81e99bf01140fd9",
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                "name": "https://git.kernel.org/stable/c/8ae0185255eaf05bd66f4215c81e99bf01140fd9"
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                "url": "https://git.kernel.org/stable/c/b42c0a33dfdd451d9be62dd5de58c39f2750b6e3",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/b42c0a33dfdd451d9be62dd5de58c39f2750b6e3"
            },
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                "url": "https://git.kernel.org/stable/c/772b9f59657665af3b68d24d12b9d172d31f0dfb",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/772b9f59657665af3b68d24d12b9d172d31f0dfb"
            },
            {
                "url": "https://git.kernel.org/stable/c/a992a283c0b77d0a7c2c348add0e6a21fb1dab67",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/a992a283c0b77d0a7c2c348add0e6a21fb1dab67"
            },
            {
                "url": "https://git.kernel.org/stable/c/1cb02dc76f4c0a2749a02b26469512d6984252e9",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/1cb02dc76f4c0a2749a02b26469512d6984252e9"
            },
            {
                "url": "https://git.kernel.org/stable/c/6086f957416a6e87236c06079fcaba7a3998aeca",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/6086f957416a6e87236c06079fcaba7a3998aeca"
            },
            {
                "url": "https://git.kernel.org/stable/c/d757bf4c69cda3c3ab7f775dfabbf5a80e2f6f9d",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/d757bf4c69cda3c3ab7f775dfabbf5a80e2f6f9d"
            },
            {
                "url": "https://git.kernel.org/stable/c/8e947c8f4a5620df77e43c9c75310dc510250166",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8e947c8f4a5620df77e43c9c75310dc510250166"
            }
        ]
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    "generator": {
        "engine": "bippy-a5840b7849dd"
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}