5.5

CVE-2021-47221

In the Linux kernel, the following vulnerability has been resolved:

mm/slub: actually fix freelist pointer vs redzoning

It turns out that SLUB redzoning ("slub_debug=Z") checks from
s->object_size rather than from s->inuse (which is normally bumped to
make room for the freelist pointer), so a cache created with an object
size less than 24 would have the freelist pointer written beyond
s->object_size, causing the redzone to be corrupted by the freelist
pointer.  This was very visible with "slub_debug=ZF":

  BUG test (Tainted: G    B            ): Right Redzone overwritten
  -----------------------------------------------------------------------------

  INFO: 0xffff957ead1c05de-0xffff957ead1c05df @offset=1502. First byte 0x1a instead of 0xbb
  INFO: Slab 0xffffef3950b47000 objects=170 used=170 fp=0x0000000000000000 flags=0x8000000000000200
  INFO: Object 0xffff957ead1c05d8 @offset=1496 fp=0xffff957ead1c0620

  Redzone  (____ptrval____): bb bb bb bb bb bb bb bb               ........
  Object   (____ptrval____): 00 00 00 00 00 f6 f4 a5               ........
  Redzone  (____ptrval____): 40 1d e8 1a aa                        @....
  Padding  (____ptrval____): 00 00 00 00 00 00 00 00               ........

Adjust the offset to stay within s->object_size.

(Note that no caches of in this size range are known to exist in the
kernel currently.)

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 >= 5.7 < 5.10.46
Linux ≫ Linux Kernel Version >= 5.11 < 5.12.13
Linux ≫ Linux Kernel Version5.13 Updaterc1
Linux ≫ Linux Kernel Version5.13 Updaterc2
Linux ≫ Linux Kernel Version5.13 Updaterc3
Linux ≫ Linux Kernel Version5.13 Updaterc4
Linux ≫ Linux Kernel Version5.13 Updaterc5
Linux ≫ Linux Kernel Version5.13 Updaterc6
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.02% 0.04
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-763 Release of Invalid Pointer or Reference

The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.