CVE-2026-43205: dpaa2-switch: validate num_ifs to prevent out-of-bounds write

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-06 · updated 2026-06-17
Weakness: CWE-787

Description

In the Linux kernel, the following vulnerability has been resolved: dpaa2-switch: validate num_ifs to prevent out-of-bounds write The driver obtains sw_attr.num_ifs from firmware via dpsw_get_attributes() but never validates it against DPSW_MAX_IF (64). This value controls iteration in dpaa2_switch_fdb_get_flood_cfg(), which writes port indices into the fixed-size cfg->if_id[DPSW_MAX_IF] array. When firmware reports num_ifs >= 64, the loop can write past the array bounds. Add a bound check for num_ifs in dpaa2_switch_init(). dpaa2_switch_fdb_get_flood_cfg() appends the control interface (port num_ifs) after all matched ports. When num_ifs == DPSW_MAX_IF and all ports match the flood filter, the loop fills all 64 slots and the control interface write overflows by one entry. The check uses >= because num_ifs == DPSW_MAX_IF is also functionally broken. build_if_id_bitmap() silently drops any ID >= 64: if (id[i] < DPSW_MAX_IF) bmap[id[i] / 64] |= ...

Affected products

Linux kernel: from 5.13 before 5.15.202; from 5.16 before 6.1.165; from 6.2 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.16; from 6.19 before 6.19.6 — fixed in 5.15.202, 6.1.165, 6.12.75, 6.18.16, 6.19.6, 6.6.128

How to fix

Upgrade to a fixed version: Linux kernel 5.15.202, 6.1.165, 6.12.75, 6.18.16. Check the vendor advisory for mitigations.

References

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