Vulnerability · Published Dec 30, 2025 · Assigned by Linux
CVE-2023-54203ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr
Critical 9.1
In plain English
A critical-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-out-of-bounds in init_smb2_rsp_hdr When smb1 mount fails, KASAN detect slab-out-of-bounds in init_smb2_rsp_hdr like the following one. For smb1 negotiate(56bytes) , init_smb2_rsp_hdr() for smb2 is called. The issue occurs while handling smb1 negotiate as smb2 server operations. Add smb server operations for smb1 (get_cmd_val, init_rsp_hdr, allocate_rsp_buf, check_user_session) to handle smb1 negotiate so that smb2 server operation does not handle it. [ 411.400423] CIFS: VFS: Use of the less secure dialect vers=1.0 is not recommended unless required for access to very old servers [ 411.400452] CIFS: Attempting to mount \\192.168.45.139\homes [ 411.479312] ksmbd: init_smb2_rsp_hdr : 492 [ 411.479323] ================================================================== [ 411.479327] BUG: KASAN: slab-out-of-bounds in init_smb2_rsp_hdr+0x1e2/0x1f4 [ksmbd] [ 411.479369] Read of size 16 at addr ffff888488ed0734 by task kworker/14:1/199 [ 411.479379] CPU: 14 PID: 199 Comm: kworker/14:1 Tainted: G OE 6.1.21 #3 [ 411.479386] Hardware name: ASUSTeK COMPUTER INC. Z10PA-D8 Series/Z10PA-D8 Series, BIOS 3801 08/23/2019 [ 411.479390] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd] [ 411.479425] Call Trace: [ 411.479428] <TASK> [ 411.479432] dump_stack_lvl+0x49/0x63 [ 411.479444] print_report+0x171/0x4a8 [ 411.479452] ? kasan_complete_mode_report_info+0x3c/0x200 [ 411.479463] ? init_smb2_rsp_hdr+0x1e2/0x1f4 [ksmbd] [ 411.479497] kasan_report+0xb4/0x130 [ 411.479503] ? init_smb2_rsp_hdr+0x1e2/0x1f4 [ksmbd] [ 411.479537] kasan_check_range+0x149/0x1e0 [ 411.479543] memcpy+0x24/0x70 [ 411.479550] init_smb2_rsp_hdr+0x1e2/0x1f4 [ksmbd] [ 411.479585] handle_ksmbd_work+0x109/0x760 [ksmbd] [ 411.479616] ? _raw_spin_unlock_irqrestore+0x50/0x50 [ 411.479624] ? smb3_encrypt_resp+0x340/0x340 [ksmbd] [ 411.479656] process_one_work+0x49c/0x790 [ 411.479667] worker_thread+0x2b1/0x6e0 [ 411.479674] ? process_one_work+0x790/0x790 [ 411.479680] kthread+0x177/0x1b0 [ 411.479686] ? kthread_complete_and_exit+0x30/0x30 [ 411.479692] ret_from_fork+0x22/0x30 [ 411.479702] </TASK>
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | linux | 5.15.0-102.112 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-aws | 5.15.0-1057.63 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-aws-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-aws-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-azure | 5.15.0-1060.69 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-azure-6.11 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-azure-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-azure-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-azure-fde | 5.15.0-1060.69.1 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-gcp | 5.15.0-1055.63 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-gcp-6.11 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-gke | 5.15.0-1054.59 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-gkeop | 5.15.0-1040.46 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-hwe-6.11 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-ibm | 5.15.0-1050.53 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-intel-iotg | 5.15.0-1052.58 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-kvm | 5.15.0-1054.59 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-lowlatency | 5.15.0-102.112 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-lowlatency-hwe-6.11 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-nvidia | 5.15.0-1048.48 | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-nvidia-6.11 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-nvidia-tegra | 5.15.0-1025.25 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-nvidia-tegra-igx | 5.15.0-1012.12 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-oem-6.0 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-oem-6.1 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-oem-6.11 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-oem-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-oem-6.8 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-oracle | 5.15.0-1055.61 | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-raspi | 5.15.0-1050.53 | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:24.04:LTS | linux-riscv-6.14 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | no fix listed | UBUNTU-CVE-2023-54203 |
| Ubuntu:22.04:LTS | linux-xilinx-zynqmp | 5.15.0-1030.34 | UBUNTU-CVE-2023-54203 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | 51a8534c0f35c0401e45f1055f914729cad98bf9 – before 921536046bd165efeb07beef5630aff35cd6a4890b3ec5671ac06829ccebdaeec05acedfec327f42 – before a8334a0c535d0f0b4d64926c8fe0922ed98f7d43cc32cd98a0aee4cc3eb611cbce11795b1aaa738a – before 99a51c673b1d2d0b5a972353401b77612d9cc71339b291b86b5988bf8753c3874d5c773399d09b96 – before dc8289f912387c3bcfbc5d2db29c8947fa207c11 |
| Linux | Linux | 5.15.105 – before 5.15.1456.1.22 – before 6.1.246.2.9 – before 6.2.11 |