CVE-2024-26878

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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.