kernel/module.c:2450 copy_module_from_user() war

Hi Kees,

FYI, there are new smatch warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git next-ima-new-check-module-syscall
head:   3167cf7685efd4855ed9e52e8b2470e8d2dcbf9c
commit: e0eb8f8fe012a54af6d00e0d1573cf1c824023d4 [32/34] module: add syscall to load module from fd

All smatch warnings:

arch/x86/include/asm/stacktrace.h:112 caller_frame_pointer() error: potentially derefencing uninitialized 'frame'. arch/x86/include/asm/jump_label.h:25 arch_static_branch() info: ignoring unreachable code.
+ kernel/module.c:2450 copy_module_from_user() warn: maybe return -EFAULT instead of the bytes remaining?

vim +2450 kernel/module.c
2440 goto free_hdr;
2441
2442 err = check_info(info);
2443 if (err)
2444 goto free_hdr;
2445
2446 return err;
2447
2448 free_hdr:
2449 vfree(info->hdr);

2451 }
2452
2453 /* Sets info->hdr and info->len. */
2454 int copy_module_from_fd(int fd, struct load_info *info)
2455 {
2456 struct file *file;
2457 int err;
2458 struct kstat stat;
2459 unsigned long size;
2460 off_t pos;

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0-DAY kernel build testing backend Open Source Technology Centre
Fengguang Wu <[email protected]> Intel Corporation