CVE-2021-47343

MEDIUM
Published May 21, 2024 Modified May 12, 2025 CWE-1188

Description

In the Linux kernel, the following vulnerability has been resolved: dm btree remove: assign new_root only when removal succeeds remove_raw() in dm_btree_remove() may fail due to IO read error (e.g. read the content of origin block fails during shadowing), and the value of shadow_spine::root is uninitialized, but the uninitialized value is still assign to new_root in the end of dm_btree_remove(). For dm-thin, the value of pmd->details_root or pmd->root will become an uninitialized value, so if trying to read details_info tree again out-of-bound memory may occur as showed below: general protection fault, probably for non-canonical address 0x3fdcb14c8d7520 CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6 Hardware name: QEMU Standard PC RIP: 0010:metadata_ll_load_ie+0x14/0x30 Call Trace: sm_metadata_count_is_more_than_one+0xb9/0xe0 dm_tm_shadow_block+0x52/0x1c0 shadow_step+0x59/0xf0 remove_raw+0xb2/0x170 dm_btree_remove+0xf4/0x1c0 dm_pool_delete_thin_device+0xc3/0x140 pool_message+0x218/0x2b0 target_message+0x251/0x290 ctl_ioctl+0x1c4/0x4d0 dm_ctl_ioctl+0xe/0x20 __x64_sys_ioctl+0x7b/0xb0 do_syscall_64+0x40/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixing it by only assign new_root when removal succeeds

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CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-1188 CWE-1188

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/4c84b3e0728ffe10d89c633694c35a02b5c477dc https://git.kernel.org/stable/c/73f27adaa73e3057a9ec464e33c4f54d34ea5de3 https://git.kernel.org/stable/c/89bf942314b78d454db92427201421b5dec132d9 https://git.kernel.org/stable/c/8fbae4a1bdb5b889490cdee929e68540151536e5 https://git.kernel.org/stable/c/964d57d1962d7e68f0f578f05d9ae4a104d74851 https://git.kernel.org/stable/c/ad365e9351ac2b450e7e79932ff6abf59342d91a https://git.kernel.org/stable/c/b6e58b5466b2959f83034bead2e2e1395cca8aeb https://git.kernel.org/stable/c/ba47e65a5de3e0e8270301a409fc63d3129fdb9e https://git.kernel.org/stable/c/c154775619186781aaf8a99333ac07437a1768d5 https://git.kernel.org/stable/c/4c84b3e0728ffe10d89c633694c35a02b5c477dc https://git.kernel.org/stable/c/73f27adaa73e3057a9ec464e33c4f54d34ea5de3 https://git.kernel.org/stable/c/89bf942314b78d454db92427201421b5dec132d9 https://git.kernel.org/stable/c/8fbae4a1bdb5b889490cdee929e68540151536e5 https://git.kernel.org/stable/c/964d57d1962d7e68f0f578f05d9ae4a104d74851 https://git.kernel.org/stable/c/ad365e9351ac2b450e7e79932ff6abf59342d91a https://git.kernel.org/stable/c/b6e58b5466b2959f83034bead2e2e1395cca8aeb https://git.kernel.org/stable/c/ba47e65a5de3e0e8270301a409fc63d3129fdb9e https://git.kernel.org/stable/c/c154775619186781aaf8a99333ac07437a1768d5

Frequently Asked Questions

What is CVE-2021-47343? +
In the Linux kernel, the following vulnerability has been resolved: dm btree remove: assign new_root only when removal succeeds remove_raw() in dm_btree_remove() may fail due to IO read error (e.g. read the content of origin block fails during shadowing), and the value of shadow_spine::root is uninitialized, but the uninitialized value is still assign to new_root in the end of dm_btree_remove(). For dm-thin, the value of pmd->details_root or pmd->root will become an uninitialized value, so if trying to read details_info tree again out-of-bound memory may occur as showed below: general protection fault, probably for non-canonical address 0x3fdcb14c8d7520 CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6 Hardware name: QEMU Standard PC RIP: 0010:metadata_ll_load_ie+0x14/0x30 Call Trace: sm_metadata_count_is_more_than_one+0xb9/0xe0 dm_tm_shadow_block+0x52/0x1c0 shadow_step+0x59/0xf0 remove_raw+0xb2/0x170 dm_btree_remove+0xf4/0x1c0 dm_pool_delete_thin_device+0xc3/0x140 pool_message+0x218/0x2b0 target_message+0x251/0x290 ctl_ioctl+0x1c4/0x4d0 dm_ctl_ioctl+0xe/0x20 __x64_sys_ioctl+0x7b/0xb0 do_syscall_64+0x40/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixing it by only assign new_root when removal succeeds It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2021-47343? +
CVE-2021-47343 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2021-47343? +
CVE-2021-47343 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47343? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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