On Wed, Nov 05, 2025 at 03:23:16PM +0100, Petr Mladek wrote:
> __sprint_symbol() might access an invalid pointer when
> kallsyms_lookup_buildid() returns a symbol found by
> ftrace_mod_address_lookup().
>
> The ftrace lookup function must set both @modname and @modbuildid
> the same way as module_address_lookup().
>
> Fixes: 9294523e3768 ("module: add printk formats to add module build ID to
> stacktraces")
> Signed-off-by: Petr Mladek <[email protected]>
> ---
> include/linux/ftrace.h | 6 ++++--
> kernel/kallsyms.c | 4 ++--
> kernel/trace/ftrace.c | 5 ++++-
> 3 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
> index 7ded7df6e9b5..a003cf1b32d0 100644
> --- a/include/linux/ftrace.h
> +++ b/include/linux/ftrace.h
> @@ -87,11 +87,13 @@ struct ftrace_hash;
> defined(CONFIG_DYNAMIC_FTRACE)
> int
> ftrace_mod_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);
> #else
> static inline int
> ftrace_mod_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)
> {
> return 0;
> }
> diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
> index efb12b077220..71868a76e9a1 100644
> --- a/kernel/kallsyms.c
> +++ b/kernel/kallsyms.c
> @@ -378,8 +378,8 @@ static int kallsyms_lookup_buildid(unsigned long addr,
> modname, modbuildid, namebuf);
>
> if (!ret)
> - ret = ftrace_mod_address_lookup(addr, symbolsize,
> - offset, modname, namebuf);
> + ret = ftrace_mod_address_lookup(addr, symbolsize, offset,
> + modname, modbuildid, namebuf);
>
> return ret;
> }
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 42bd2ba68a82..11f5096fb60c 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -7678,7 +7678,8 @@ ftrace_func_address_lookup(struct ftrace_mod_map
> *mod_map,
>
> int
> ftrace_mod_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)
> {
> struct ftrace_mod_map *mod_map;
> int ret = 0;
> @@ -7690,6 +7691,8 @@ ftrace_mod_address_lookup(unsigned long addr, unsigned
> long *size,
> if (ret) {
> if (modname)
> *modname = mod_map->mod->name;
> + if (modbuildid)
> + *modbuildid = module_buildid(mod_map->mod);
> break;
> }
> }
> --
> 2.51.1
>
>
Reviewed-by: Aaron Tomlin <[email protected]>
--
Aaron Tomlin
