For compat processes, userspace size for syms pointers is different. Provide compat handling for copying array elements from the user space.
Fixes: 0dcac272540613d4 ("bpf: Add multi kprobe link") Signed-off-by: Eugene Syromiatnikov esyr@redhat.com --- kernel/trace/bpf_trace.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index a93a54f..9d3028a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2253,6 +2253,24 @@ struct user_syms { char *buf; };
+static inline int get_arr_ptr(unsigned long *p, + unsigned long __user *uaddr, u32 idx) +{ + if (unlikely(in_compat_syscall())) { + compat_uptr_t __user *compat_uaddr = (compat_uptr_t __user *)uaddr; + compat_uptr_t val; + int err; + + err = __get_user(val, compat_uaddr + idx); + if (!err) + *p = val; + + return err; + } else { + return __get_user(*p, uaddr + idx); + } +} + static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) { unsigned long __user usymbol; @@ -2270,7 +2288,7 @@ static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 goto error;
for (p = buf, i = 0; i < cnt; i++) { - if (__get_user(usymbol, usyms + i)) { + if (get_arr_ptr(&usymbol, usyms, i)) { err = -EFAULT; goto error; }