5.5

CVE-2022-50506

drbd: only clone bio if we have a backing device

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

drbd: only clone bio if we have a backing device

Commit c347a787e34cb (drbd: set ->bi_bdev in drbd_req_new) moved a
bio_set_dev call (which has since been removed) to "earlier", from
drbd_request_prepare to drbd_req_new.

The problem is that this accesses device->ldev->backing_bdev, which is
not NULL-checked at this point. When we don't have an ldev (i.e. when
the DRBD device is diskless), this leads to a null pointer deref.

So, only allocate the private_bio if we actually have a disk. This is
also a small optimization, since we don't clone the bio to only to
immediately free it again in the diskless case.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 5.18 < 6.0.6
Linux ≫ Linux Kernel Version6.1 Updaterc1
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.13% 0.028
CVSS Metriken
Quelle 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-476 NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

https://git.kernel.org/stable/c/05580a3bbf3cec677cb00a85dfeb21d6a9b48eaf
Patch
https://git.kernel.org/stable/c/6d42ddf7f27b6723549ee6d4c8b1b418b59bf6b5
Patch