From 8861fd576ecf96450f42f3eb4b56cad5bf12188a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 19 Feb 2020 09:32:55 -0500 Subject: binfmt_flat: don't use __put_user() ... and check the return value Signed-off-by: Al Viro --- fs/binfmt_flat.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 831a2b25ba79..7b663ed5247b 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -138,35 +138,40 @@ static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN; sp = (unsigned long __user *)current->mm->start_stack; - __put_user(bprm->argc, sp++); + if (put_user(bprm->argc, sp++)) + return -EFAULT; if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) { unsigned long argv, envp; argv = (unsigned long)(sp + 2); envp = (unsigned long)(sp + 2 + bprm->argc + 1); - __put_user(argv, sp++); - __put_user(envp, sp++); + if (put_user(argv, sp++) || put_user(envp, sp++)) + return -EFAULT; } current->mm->arg_start = (unsigned long)p; for (i = bprm->argc; i > 0; i--) { - __put_user((unsigned long)p, sp++); + if (put_user((unsigned long)p, sp++)) + return -EFAULT; len = strnlen_user(p, MAX_ARG_STRLEN); if (!len || len > MAX_ARG_STRLEN) return -EINVAL; p += len; } - __put_user(0, sp++); + if (put_user(0, sp++)) + return -EFAULT; current->mm->arg_end = (unsigned long)p; current->mm->env_start = (unsigned long) p; for (i = bprm->envc; i > 0; i--) { - __put_user((unsigned long)p, sp++); + if (put_user((unsigned long)p, sp++)) + return -EFAULT; len = strnlen_user(p, MAX_ARG_STRLEN); if (!len || len > MAX_ARG_STRLEN) return -EINVAL; p += len; } - __put_user(0, sp++); + if (put_user(0, sp++)) + return -EFAULT; current->mm->env_end = (unsigned long)p; return 0; @@ -998,7 +1003,8 @@ static int load_flat_binary(struct linux_binprm *bprm) unsigned long __user *sp; current->mm->start_stack -= sizeof(unsigned long); sp = (unsigned long __user *)current->mm->start_stack; - __put_user(start_addr, sp); + if (put_user(start_addr, sp)) + return -EFAULT; start_addr = libinfo.lib_list[i].entry; } } -- cgit v1.2.3