net: dcb: choose correct policy to parse DCB_ATTR_BCN

Description

In the Linux kernel, the following vulnerability has been resolved: net: dcb: choose correct policy to parse DCB_ATTR_BCN The dcbnl_bcn_setcfg uses erroneous policy to parse tb[DCB_ATTR_BCN], which is introduced in commit 859ee3c43812 ("DCB: Add support for DCB BCN"). Please see the comment in below code static int dcbnl_bcn_setcfg(...) { ... ret = nla_parse_nested_deprecated(..., dcbnl_pfc_up_nest, .. ) // !!! dcbnl_pfc_up_nest for attributes // DCB_PFC_UP_ATTR_0 to DCB_PFC_UP_ATTR_ALL in enum dcbnl_pfc_up_attrs ... for (i = DCB_BCN_ATTR_RP_0; i <= DCB_BCN_ATTR_RP_7; i++) { // !!! DCB_BCN_ATTR_RP_0 to DCB_BCN_ATTR_RP_7 in enum dcbnl_bcn_attrs ... value_byte = nla_get_u8(data[i]); ... } ... for (i = DCB_BCN_ATTR_BCNA_0; i <= DCB_BCN_ATTR_RI; i++) { // !!! DCB_BCN_ATTR_BCNA_0 to DCB_BCN_ATTR_RI in enum dcbnl_bcn_attrs ... value_int = nla_get_u32(data[i]); ... } ... } That is, the nla_parse_nested_deprecated uses dcbnl_pfc_up_nest attributes to parse nlattr defined in dcbnl_pfc_up_attrs. But the following access code fetch each nlattr as dcbnl_bcn_attrs attributes. By looking up the associated nla_policy for dcbnl_bcn_attrs. We can find the beginning part of these two policies are "same". static const struct nla_policy dcbnl_pfc_up_nest[...] = { [DCB_PFC_UP_ATTR_0] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_1] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_2] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_3] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_4] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_5] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_6] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_7] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_ALL] = {.type = NLA_FLAG}, }; static const struct nla_policy dcbnl_bcn_nest[...] = { [DCB_BCN_ATTR_RP_0] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_1] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_2] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_3] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_4] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_5] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_6] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_7] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_ALL] = {.type = NLA_FLAG}, // from here is somewhat different [DCB_BCN_ATTR_BCNA_0] = {.type = NLA_U32}, ... [DCB_BCN_ATTR_ALL] = {.type = NLA_FLAG}, }; Therefore, the current code is buggy and this nla_parse_nested_deprecated could overflow the dcbnl_pfc_up_nest and use the adjacent nla_policy to parse attributes from DCB_BCN_ATTR_BCNA_0. Hence use the correct policy dcbnl_bcn_nest to parse the nested tb[DCB_ATTR_BCN] TLV.

Scores

EPSS (exploitation in 30 days)

0.18% · top 93% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Weakness

• CWE-noinfo Not enough information

Affected products

• Linux · Linux

  • affected 859ee3c43812051e21816c6d6d4cc04fb7ce9b2e – < 5b3dbedb8d4a0f9f7ce904d76b885438af2a21f9
  • affected 859ee3c43812051e21816c6d6d4cc04fb7ce9b2e – < 8e309f43d0ca4051d20736c06a6f84bbddd881da
  • affected 859ee3c43812051e21816c6d6d4cc04fb7ce9b2e – < a0da2684db18dead3bcee12fb185e596e3d63c2b
  • affected 859ee3c43812051e21816c6d6d4cc04fb7ce9b2e – < ecff20e193207b44fdbfe64d7de89890f0a7fe6c
  • affected 859ee3c43812051e21816c6d6d4cc04fb7ce9b2e – < 199fde04bd875d28b3a5ca525eaaa004eec6e947
  • affected 859ee3c43812051e21816c6d6d4cc04fb7ce9b2e – < 31d49ba033095f6e8158c60f69714a500922e0c3

• Linux · Linux

  • affected 2.6.29
  • unaffected < 2.6.29
  • unaffected 5.4.253 – ≤ 5.4.*
  • unaffected 5.10.190 – ≤ 5.10.*
  • unaffected 5.15.126 – ≤ 5.15.*
  • unaffected 6.1.45 – ≤ 6.1.*
  • unaffected 6.4.10 – ≤ 6.4.*
  • unaffected 6.5 – ≤ *

References (6)

• https://git.kernel.org/stable/c/5b3dbedb8d4a0f9f7ce904d76b885438af2a21f9 (opens in a new tab)
• https://git.kernel.org/stable/c/8e309f43d0ca4051d20736c06a6f84bbddd881da (opens in a new tab)
• https://git.kernel.org/stable/c/a0da2684db18dead3bcee12fb185e596e3d63c2b (opens in a new tab)
• https://git.kernel.org/stable/c/ecff20e193207b44fdbfe64d7de89890f0a7fe6c (opens in a new tab)
• https://git.kernel.org/stable/c/199fde04bd875d28b3a5ca525eaaa004eec6e947 (opens in a new tab)
• https://git.kernel.org/stable/c/31d49ba033095f6e8158c60f69714a500922e0c3 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2023-53369](https://trackcve.app/badge/CVE-2023-53369.svg)](https://trackcve.app/cve/CVE-2023-53369)

Record last updated 11 May 2026, 19:43 UTC.