On Sat, Dec 20, 2025 at 8:19 AM Maurice Hieronymus <[email protected]> wrote: > > modbuildid is never set when kallsyms_lookup_buildid is returning via > successful bpf_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 > Signed-off-by: Maurice Hieronymus <[email protected]> > --- > include/linux/filter.h | 6 ++++-- > kernel/kallsyms.c | 2 +- > 2 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/include/linux/filter.h b/include/linux/filter.h > index fd54fed8f95f..eb1d1c876503 100644 > --- a/include/linux/filter.h > +++ b/include/linux/filter.h > @@ -1384,12 +1384,14 @@ struct bpf_prog *bpf_prog_ksym_find(unsigned long > addr); > > static inline int > bpf_address_lookup(unsigned long addr, unsigned long *size, > - unsigned long *off, char **modname, char *sym) > + unsigned long *off, char **modname, const unsigned char > **modbuildid, char *sym) > { > int ret = __bpf_address_lookup(addr, size, off, sym); > > if (ret && modname) > *modname = NULL; > + if (ret && modbuildid) > + *modbuildid = NULL; > return ret; > } > > @@ -1455,7 +1457,7 @@ static inline struct bpf_prog > *bpf_prog_ksym_find(unsigned long addr) > > static inline int > bpf_address_lookup(unsigned long addr, unsigned long *size, > - unsigned long *off, char **modname, char *sym) > + unsigned long *off, char **modname, const unsigned char > **modbuildid, char *sym)
No. Please search the earlier threads where this was discussed. The patches to fix this were posted and I think they landed in some tree already. pw-bot: cr
