5.5

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

Verknüpft mit AI von unstrukturierten Daten zu bestehenden CPE der NVD
This information is available to logged-in users.
Data is provided by the National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version < 4.4.276
Linux ≫ Linux Kernel Version >= 4.5 < 4.9.276
Linux ≫ Linux Kernel Version >= 4.10 < 4.14.240
Linux ≫ Linux Kernel Version >= 4.15 < 4.19.198
Linux ≫ Linux Kernel Version >= 4.20 < 5.4.133
Linux ≫ Linux Kernel Version >= 5.5 < 5.10.51
Linux ≫ Linux Kernel Version >= 5.11 < 5.12.18
Linux ≫ Linux Kernel Version >= 5.13 < 5.13.3
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.01% 0.013
CVSS Metriken
Source Base Score Exploit Score Impact Score Vector string
nvd@nist.gov 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-1188 Initialization of a Resource with an Insecure Default

The product initializes or sets a resource with a default that is intended to be changed by the administrator, but the default is not secure.