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vulnrichmentLinuxVULNRICHMENT:CVE-2024-26878
HistoryApr 17, 2024 - 10:27 a.m.

CVE-2024-26878 quota: Fix potential NULL pointer dereference

2024-04-1710:27:35
Linux
github.com
2
linux kernel
cve-2024-26878
quota vulnerability

AI Score

6.9

Confidence

Low

SSVC

Exploitation

none

Automatable

no

Technical Impact

partial

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

quota: Fix potential NULL pointer dereference

Below race may cause NULL pointer dereference

P1 P2
dquot_free_inode quota_off
drop_dquot_ref
remove_dquot_ref
dquots = i_dquot(inode)
dquots = i_dquot(inode)
srcu_read_lock
dquots[cnt]) != NULL (1)
dquots[type] = NULL (2)
spin_lock(&dquots[cnt]->dq_dqb_lock) (3)

If dquot_free_inode(or other routines) checks inode’s quota pointers (1)
before quota_off sets it to NULL(2) and use it (3) after that, NULL pointer
dereference will be triggered.

So let’s fix it by using a temporary pointer to avoid this issue.

AI Score

6.9

Confidence

Low

SSVC

Exploitation

none

Automatable

no

Technical Impact

partial