4.7

CVE-2024-26878

quota: Fix potential NULL pointer dereference

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version < 4.19.311
Linux ≫ Linux Kernel Version >= 4.20 < 5.4.273
Linux ≫ Linux Kernel Version >= 5.5 < 5.10.214
Linux ≫ Linux Kernel Version >= 5.11 < 5.15.153
Linux ≫ Linux Kernel Version >= 5.16 < 6.1.83
Linux ≫ Linux Kernel Version >= 6.2 < 6.6.23
Linux ≫ Linux Kernel Version >= 6.7 < 6.7.11
Linux ≫ Linux Kernel Version >= 6.8 < 6.8.2
Debian ≫ Debian Linux Version10.0
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EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.01% 0.003
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 4.7 1 3.6
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

CWE-476 NULL Pointer Dereference

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