CVE-2023-54206
net/sched: flower: fix filter idr initialization
Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: flower: fix filter idr initialization The cited commit moved idr initialization too early in fl_change() which allows concurrent users to access the filter that is still being initialized and is in inconsistent state, which, in turn, can cause NULL pointer dereference [0]. Since there is no obvious way to fix the ordering without reverting the whole cited commit, alternative approach taken to first insert NULL pointer into idr in order to allocate the handle but still cause fl_get() to return NULL and prevent concurrent users from seeing the filter while providing miss-to-action infrastructure with valid handle id early in fl_change(). [ 152.434728] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN [ 152.436163] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 152.437269] CPU: 4 PID: 3877 Comm: tc Not tainted 6.3.0-rc4+ #5 [ 152.438110] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 152.439644] RIP: 0010:fl_dump_key+0x8b/0x1d10 [cls_flower] [ 152.440461] Code: 01 f2 02 f2 c7 40 08 04 f2 04 f2 c7 40 0c 04 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 00 01 00 00 48 89 c8 48 c1 e8 03 <0f> b6 04 10 84 c0 74 08 3c 03 0f 8e 98 19 00 00 8b 13 85 d2 74 57 [ 152.442885] RSP: 0018:ffff88817a28f158 EFLAGS: 00010246 [ 152.443851] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 152.444826] RDX: dffffc0000000000 RSI: ffffffff8500ae80 RDI: ffff88810a987900 [ 152.445791] RBP: ffff888179d88240 R08: ffff888179d8845c R09: ffff888179d88240 [ 152.446780] R10: ffffed102f451e48 R11: 00000000fffffff2 R12: ffff88810a987900 [ 152.447741] R13: ffffffff8500ae80 R14: ffff88810a987900 R15: ffff888149b3c738 [ 152.448756] FS: 00007f5eb2a34800(0000) GS:ffff88881ec00000(0000) knlGS:0000000000000000 [ 152.449888] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 152.450685] CR2: 000000000046ad19 CR3: 000000010b0bd006 CR4: 0000000000370ea0 [ 152.451641] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 152.452628] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 152.453588] Call Trace: [ 152.454032] <TASK> [ 152.454447] ? netlink_sendmsg+0x7a1/0xcb0 [ 152.455109] ? sock_sendmsg+0xc5/0x190 [ 152.455689] ? ____sys_sendmsg+0x535/0x6b0 [ 152.456320] ? ___sys_sendmsg+0xeb/0x170 [ 152.456916] ? do_syscall_64+0x3d/0x90 [ 152.457529] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 152.458321] ? ___sys_sendmsg+0xeb/0x170 [ 152.458958] ? __sys_sendmsg+0xb5/0x140 [ 152.459564] ? do_syscall_64+0x3d/0x90 [ 152.460122] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 152.460852] ? fl_dump_key_options.part.0+0xea0/0xea0 [cls_flower] [ 152.461710] ? _raw_spin_lock+0x7a/0xd0 [ 152.462299] ? _raw_read_lock_irq+0x30/0x30 [ 152.462924] ? nla_put+0x15e/0x1c0 [ 152.463480] fl_dump+0x228/0x650 [cls_flower] [ 152.464112] ? fl_tmplt_dump+0x210/0x210 [cls_flower] [ 152.464854] ? __kmem_cache_alloc_node+0x1a7/0x330 [ 152.465592] ? nla_put+0x15e/0x1c0 [ 152.466160] tcf_fill_node+0x515/0x9a0 [ 152.466766] ? tc_setup_offload_action+0xf0/0xf0 [ 152.467463] ? __alloc_skb+0x13c/0x2a0 [ 152.468067] ? __build_skb_around+0x330/0x330 [ 152.468814] ? fl_get+0x107/0x1a0 [cls_flower] [ 152.469503] tc_del_tfilter+0x718/0x1330 [ 152.470115] ? is_bpf_text_address+0xa/0x20 [ 152.470765] ? tc_ctl_chain+0xee0/0xee0 [ 152.471335] ? __kernel_text_address+0xe/0x30 [ 152.471948] ? unwind_get_return_address+0x56/0xa0 [ 152.472639] ? __thaw_task+0x150/0x150 [ 152.473218] ? arch_stack_walk+0x98/0xf0 [ 152.473839] ? __stack_depot_save+0x35/0x4c0 [ 152.474501] ? stack_trace_save+0x91/0xc0 [ 152.475119] ? security_capable+0x51/0x90 [ 152.475741] rtnetlink_rcv_msg+0x2c1/0x9d0 [ 152.476387] ? rtnl_calcit.isra.0+0x2b0/0x2b0 [ 152.477042] ---truncated---
INFO
Published Date :
Dec. 30, 2025, 1:16 p.m.
Last Modified :
Dec. 30, 2025, 1:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2023-54206
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply the latest Linux kernel security updates.
- Verify the kernel version after applying updates.
- Restart the affected systems.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2023-54206.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/253a3a324e0ebc2825de76a0f5f17b8383b2023d | |
| https://git.kernel.org/stable/c/dd4f6bbfa646f258e5bcdfac57a5c413d687f588 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2023-54206 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2023-54206
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2023-54206 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2023-54206 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dec. 30, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: net/sched: flower: fix filter idr initialization The cited commit moved idr initialization too early in fl_change() which allows concurrent users to access the filter that is still being initialized and is in inconsistent state, which, in turn, can cause NULL pointer dereference [0]. Since there is no obvious way to fix the ordering without reverting the whole cited commit, alternative approach taken to first insert NULL pointer into idr in order to allocate the handle but still cause fl_get() to return NULL and prevent concurrent users from seeing the filter while providing miss-to-action infrastructure with valid handle id early in fl_change(). [ 152.434728] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN [ 152.436163] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 152.437269] CPU: 4 PID: 3877 Comm: tc Not tainted 6.3.0-rc4+ #5 [ 152.438110] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 152.439644] RIP: 0010:fl_dump_key+0x8b/0x1d10 [cls_flower] [ 152.440461] Code: 01 f2 02 f2 c7 40 08 04 f2 04 f2 c7 40 0c 04 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 00 01 00 00 48 89 c8 48 c1 e8 03 <0f> b6 04 10 84 c0 74 08 3c 03 0f 8e 98 19 00 00 8b 13 85 d2 74 57 [ 152.442885] RSP: 0018:ffff88817a28f158 EFLAGS: 00010246 [ 152.443851] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 152.444826] RDX: dffffc0000000000 RSI: ffffffff8500ae80 RDI: ffff88810a987900 [ 152.445791] RBP: ffff888179d88240 R08: ffff888179d8845c R09: ffff888179d88240 [ 152.446780] R10: ffffed102f451e48 R11: 00000000fffffff2 R12: ffff88810a987900 [ 152.447741] R13: ffffffff8500ae80 R14: ffff88810a987900 R15: ffff888149b3c738 [ 152.448756] FS: 00007f5eb2a34800(0000) GS:ffff88881ec00000(0000) knlGS:0000000000000000 [ 152.449888] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 152.450685] CR2: 000000000046ad19 CR3: 000000010b0bd006 CR4: 0000000000370ea0 [ 152.451641] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 152.452628] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 152.453588] Call Trace: [ 152.454032] <TASK> [ 152.454447] ? netlink_sendmsg+0x7a1/0xcb0 [ 152.455109] ? sock_sendmsg+0xc5/0x190 [ 152.455689] ? ____sys_sendmsg+0x535/0x6b0 [ 152.456320] ? ___sys_sendmsg+0xeb/0x170 [ 152.456916] ? do_syscall_64+0x3d/0x90 [ 152.457529] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 152.458321] ? ___sys_sendmsg+0xeb/0x170 [ 152.458958] ? __sys_sendmsg+0xb5/0x140 [ 152.459564] ? do_syscall_64+0x3d/0x90 [ 152.460122] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 152.460852] ? fl_dump_key_options.part.0+0xea0/0xea0 [cls_flower] [ 152.461710] ? _raw_spin_lock+0x7a/0xd0 [ 152.462299] ? _raw_read_lock_irq+0x30/0x30 [ 152.462924] ? nla_put+0x15e/0x1c0 [ 152.463480] fl_dump+0x228/0x650 [cls_flower] [ 152.464112] ? fl_tmplt_dump+0x210/0x210 [cls_flower] [ 152.464854] ? __kmem_cache_alloc_node+0x1a7/0x330 [ 152.465592] ? nla_put+0x15e/0x1c0 [ 152.466160] tcf_fill_node+0x515/0x9a0 [ 152.466766] ? tc_setup_offload_action+0xf0/0xf0 [ 152.467463] ? __alloc_skb+0x13c/0x2a0 [ 152.468067] ? __build_skb_around+0x330/0x330 [ 152.468814] ? fl_get+0x107/0x1a0 [cls_flower] [ 152.469503] tc_del_tfilter+0x718/0x1330 [ 152.470115] ? is_bpf_text_address+0xa/0x20 [ 152.470765] ? tc_ctl_chain+0xee0/0xee0 [ 152.471335] ? __kernel_text_address+0xe/0x30 [ 152.471948] ? unwind_get_return_address+0x56/0xa0 [ 152.472639] ? __thaw_task+0x150/0x150 [ 152.473218] ? arch_stack_walk+0x98/0xf0 [ 152.473839] ? __stack_depot_save+0x35/0x4c0 [ 152.474501] ? stack_trace_save+0x91/0xc0 [ 152.475119] ? security_capable+0x51/0x90 [ 152.475741] rtnetlink_rcv_msg+0x2c1/0x9d0 [ 152.476387] ? rtnl_calcit.isra.0+0x2b0/0x2b0 [ 152.477042] ---truncated--- Added Reference https://git.kernel.org/stable/c/253a3a324e0ebc2825de76a0f5f17b8383b2023d Added Reference https://git.kernel.org/stable/c/dd4f6bbfa646f258e5bcdfac57a5c413d687f588