In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_flow: fix NULL pointer dereference on shared blocks flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block. Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below: ======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...] =======================================================================
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-476
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24245b9b80> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24245b8b80> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d2357409800> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24245b8340> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24245bbd40> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23bea8bc40> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24245b9ec0> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d24245bb1c0> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d23a5377880> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d24245bb8c0> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d242438a440> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d24245b9100> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d2460137a80> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* |