CVE Published: 17/04/2024 |
CVE Updated: 05/11/2024 |
CVE Year: 2024 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2024-26878 Description
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.