[PATCH v4 0/2] kallsyms: Always initialize modbuildid
From: Maurice Hieronymus
Date: Sat Dec 20 2025 - 13:19:06 EST
modbuildid is never set when kallsyms_lookup_buildid is returning via
successful bpf_address_lookup or ftrace_mod_address_lookup.
This leads to an uninitialized pointer dereference on x86 when
CONFIG_STACKTRACE_BUILD_ID=y inside __sprint_symbol.
Prevent this by always initializing modbuildid.
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220717
Changes to v3:
- Split the changes into separate ftrace and bpf patches
- Replace IS_ENABLED() with plain #ifdef
Maurice Hieronymus (2):
kallsyms: Always initialize modbuildid on ftrace address
kallsyms: Always initialize modbuildid on bpf address
include/linux/filter.h | 6 ++++--
include/linux/ftrace.h | 4 ++--
kernel/kallsyms.c | 4 ++--
kernel/trace/ftrace.c | 8 +++++++-
4 files changed, 15 insertions(+), 7 deletions(-)
base-commit: dd9b004b7ff3289fb7bae35130c0a5c0537266af
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2.50.1