CVE-2023-53369
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-18

Last updated on: 2025-12-12

Assigner: kernel.org

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.
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Meta Information
Published
2025-09-18
Last Modified
2025-12-12
Generated
2026-05-27
AI Q&A
2025-09-18
EPSS Evaluated
2026-05-25
NVD
CVE-2023-53369
Affected Vendors & Products
Showing 9 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 2.6.29 (inc) to 5.4.253 (exc)
linux linux_kernel From 5.5 (inc) to 5.10.190 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.126 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.45 (exc)
linux linux_kernel From 6.2 (inc) to 6.4.10 (exc)
linux linux_kernel 6.5
linux linux_kernel 6.5
linux linux_kernel 6.5
linux linux_kernel 6.5
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability in the Linux kernel involves the incorrect use of a parsing policy in the function dcbnl_bcn_setcfg. The function uses the wrong nla_policy (dcbnl_pfc_up_nest) to parse nested attributes for DCB_ATTR_BCN, which should instead use dcbnl_bcn_nest. Because the two policies differ after the initial attributes, this misuse can cause an overflow in parsing, leading to incorrect handling of attributes and potential memory issues.


How can this vulnerability impact me? :

The vulnerability can lead to improper parsing of network attributes in the Linux kernel's Data Center Bridging (DCB) configuration. This may cause memory corruption or overflow, potentially leading to system instability, crashes, or exploitation by attackers to execute arbitrary code or cause denial of service.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, update the Linux kernel to a version where the dcbnl_bcn_setcfg function correctly uses the dcbnl_bcn_nest policy to parse the nested tb[DCB_ATTR_BCN] TLV, instead of the erroneous dcbnl_pfc_up_nest policy. This fix prevents potential parsing errors and overflows related to the DCB attributes.


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