In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: unconditionally bump set->nelems before insertion
In case that the set is full, a new element gets published then removed
without waiting for the RCU grace period, while RCU reader can be
walking over it already. To address this issue, add the element transaction even if set is full,
but toggle the set_full flag to report -ENFILE so the abort path safely
unwinds the set to its previous state. As for element updates, decrement set->nelems to restore it.
A simpler fix is to call synchronize_rcu() in the error path. However, with a large batch adding elements to already maxed-out set,
this could cause noticeable slowdown of such batches.
Attack Parameters
Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Vulnerable Products 4
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Linux Linux_Kernel
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
|
4.10
|
6.18.17
|
|
Linux Linux_Kernel
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
|
4.10
|
6.19.7
|
|
Linux Linux_Kernel
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
|
4.10
|
7.0-rc3
|
|
Linux Linux_Kernel
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
|
4.9.33
|
— |