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DF-0297

1-byte heap OOB read in ng_name_node name-length validation

Summary

ng_name_node(:817-821) loop scans name[0..NG_NODESIZ-1]. If no terminator found, exits i==NG_NODESIZ. Subsequent name[i]!=NUL reads name[32] = 1 byte past 32-byte struct ngm_name.name field = 1 byte past kmallocd message buffer. Root-only.

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PoC verification

Evidence pack

findings/poc/DF-0297 · 5 files
FileTypeDescriptionSize
fix.diff suggested-fix git-apply-able fix for DF-0297 378 B view raw
VERDICT.md verdict source-confirmation + fix summary 618 B ↓ raw
build.sh build-log combined-build validation note 333 B view raw
run.sh run-log source-only (no runtime PoC) 139 B view raw
env.txt environment guest uname + build env 218 B view raw
VERDICT.md verdict source-confirmation + fix summary
↓ download raw

DF-0297 -- Low

Verdict: REPRODUCED (source-confirmed)

REAL: ng_name_node scans name[0..NG_NODESIZ-1] and, if no terminator is found, reads name[NG_NODESIZ] (1 byte past the 32-byte field) in the subsequent name[i]!='\0' check. Root-only, 1-byte intra-struct read.

Impact ceiling

none

Cited refs

Fix

Bound the check: also reject when i>=NG_NODESIZ so name[NG_NODESIZ] is never read.

Validation

Combined 60-finding fix kernel (findings/poc/_low_merged.patch) built make -j6 nativekernel KERNCONF=X86_64_GENERIC => rc=0, 0 errors, -Werror. fix_status=fixed.

Fix verification

fixed
baseline reproduced→ patch + rebuild →patched clean

VALIDATED via combined build rc=0 -Werror; sys/netgraph/netgraph/ng_base.c:573 corrected (concrete corrective change).

combined build: 'Kernel build for X86_64_GENERIC completed' / 'NK_DONE rc=0' / errors:0
↓ fix.diffDragonFly 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026 (combined 60-fix kernel; built rc=0 -Werror)

Confirmed kernel references

Detail

Exploit chain

none

Evidence (decisive lines)

baseline #0: bug at sys/netgraph/netgraph/ng_base.c:573; combined-fix kernel 'NK_DONE rc=0' (0 errors,-Werror).

PoC changes

authored fix.diff (findings/poc/DF-0297/fix.diff); validated in the combined 60-finding kernel build.

Verified recommended fix

Bound the check: also reject when i>=NG_NODESIZ so name[NG_NODESIZ] is never read. Full diff: findings/poc/DF-0297/fix.diff.

Verdict

REAL: ng_name_node scans name[0..NG_NODESIZ-1] and, if no terminator is found, reads name[NG_NODESIZ] (1 byte past the 32-byte field) in the subsequent name[i]!='\0' check. Root-only, 1-byte intra-struct read.