Linux Kernel up to 5.12.2 Table Load dm_mq_init_request_queue initialization

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 5.12.2. This impacts the function dm_mq_init_request_queue of the component Table Load Handler. This manipulation causes initialization. This vulnerability appears as CVE-2021-46938. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.12.2 (Operating System). It has been declared as critical. Affected by this vulnerability is the function dm_mq_init_request_queue of the component Table Load Handler. The manipulation with an unknown input leads to a initialization vulnerability. The CWE definition for the vulnerability is CWE-665. The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: dm rq: fix double free of blk_mq_tag_set in dev remove after table load fails When loading a device-mapper table for a request-based mapped device, and the allocation/initialization of the blk_mq_tag_set for the device fails, a following device remove will cause a double free. E.g. (dmesg): device-mapper: core: Cannot initialize queue for request-based dm-mq mapped device device-mapper: ioctl: unable to set up device queue for new table. Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0305e098835de000 TEID: 0305e098835de803 Fault in home space mode while using kernel ASCE. AS:000000025efe0007 R3:0000000000000024 Oops: 0038 ilc:3 [#1] SMP Modules linked in: ... lots of modules ... Supported: Yes, External CPU: 0 PID: 7348 Comm: multipathd Kdump: loaded Tainted: G W X 5.3.18-53-default #1 SLE15-SP3 Hardware name: IBM 8561 T01 7I2 (LPAR) Krnl PSW : 0704e00180000000 000000025e368eca (kfree+0x42/0x330) 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 Krnl GPRS: 000000000000004a 000000025efe5230 c1773200d779968d 0000000000000000 000000025e520270 000000025e8d1b40 0000000000000003 00000007aae10000 000000025e5202a2 0000000000000001 c1773200d779968d 0305e098835de640 00000007a8170000 000003ff80138650 000000025e5202a2 000003e00396faa8 Krnl Code: 000000025e368eb8: c4180041e100 lgrl %r1,25eba50b8 000000025e368ebe: ecba06b93a55 risbg %r11,%r10,6,185,58 #000000025e368ec4: e3b010000008 ag %r11,0(%r1) >000000025e368eca: e310b0080004 lg %r1,8(%r11) 000000025e368ed0: a7110001 tmll %r1,1 000000025e368ed4: a7740129 brc 7,25e369126 000000025e368ed8: e320b0080004 lg %r2,8(%r11) 000000025e368ede: b904001b lgr %r1,%r11 Call Trace: [] kfree+0x42/0x330 [] blk_mq_free_tag_set+0x72/0xb8 [] dm_mq_cleanup_mapped_device+0x38/0x50 [dm_mod] [] free_dev+0x52/0xd0 [dm_mod] [] __dm_destroy+0x150/0x1d0 [dm_mod] [] dev_remove+0x162/0x1c0 [dm_mod] [] ctl_ioctl+0x198/0x478 [dm_mod] [] dm_ctl_ioctl+0x22/0x38 [dm_mod] [] ksys_ioctl+0xbe/0xe0 [] __s390x_sys_ioctl+0x2a/0x40 [] system_call+0xd8/0x2c8 Last Breaking-Event-Address: [] blk_mq_free_tag_set+0x6c/0xb8 Kernel panic - not syncing: Fatal exception: panic_on_oops When allocation/initialization of the blk_mq_tag_set fails in dm_mq_init_request_queue(), it is uninitialized/freed, but the pointer is not reset to NULL; so when dev_remove() later gets into dm_mq_cleanup_mapped_device() it sees the pointer and tries to uninitialize and free it again. Fix this by setting the pointer to NULL in dm_mq_init_request_queue() error-handling. Also set it to NULL in dm_mq_cleanup_mapped_device().

The weakness was presented 02/27/2024. It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2021-46938 since 02/25/2024. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 4.9.269, 4.14.233, 4.19.191, 5.4.118, 5.10.36, 5.11.20, 5.12.3 or 5.13 eliminates this vulnerability. Applying the patch 8ae0185255ea/b42c0a33dfdd/772b9f596576/a992a283c0b7/1cb02dc76f4c/6086f957416a/d757bf4c69cd/8e947c8f4a56 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.9.268
• 4.14.232
• 4.19.190
• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.4.117
• 5.5
• 5.6
• 5.7
• 5.8
• 5.9
• 5.10
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.11
• 5.11.0
• 5.11.1
• 5.11.2
• 5.11.3
• 5.11.4
• 5.11.5
• 5.11.6
• 5.11.7
• 5.11.8
• 5.11.9
• 5.11.10
• 5.11.11
• 5.11.12
• 5.11.13
• 5.11.14
• 5.11.15
• 5.11.16
• 5.11.17
• 5.11.18
• 5.11.19
• 5.12
• 5.12.0
• 5.12.1
• 5.12.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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