Re: [PATCH v2 3/3] audit: Use syscall_get_return_value to get syscall return code in audit_syscall_exit

On 5/11/21 6:38 AM, Paul Moore wrote: > On Fri, Apr 23, 2021 at 6:36 AM He Zhe <zhe.he(a)windriver.com&gt; wrote: >> regs_return_value for some architectures like arm64 simply retrieve >> register value from pt_regs without sign extension in 32-bit compatible >> case and cause audit to have false syscall return code. For example, >> 32-bit -13 would be treated as 4294967283 below. >> >> type=SYSCALL msg=audit(1611110715.887:582): arch=40000028 syscall=322 >> success=yes exit=4294967283 >> >> We just added proper sign extension in syscall_get_return_value which >> should be used instead. >> >> Signed-off-by: He Zhe <zhe.he(a)windriver.com&gt; >> --- >> v1 to v2: No change >> >> include/linux/audit.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > > Perhaps I missed it but did you address the compile error that was > found by the kernel test robot? I sent a patch adding syscall_get_return_value for alpha to fix this bot warning. https://lore.kernel.org/lkml/20210426091629.45020-1-zhe.he@windriver.com/ which can be found in this mail thread.

>> diff --git a/include/linux/audit.h b/include/linux/audit.h >> index 82b7c1116a85..135adbe22c19 100644 >> --- a/include/linux/audit.h >> +++ b/include/linux/audit.h >> @@ -334,7 +334,7 @@ static inline void audit_syscall_exit(void *pt_regs) >> { >> if (unlikely(audit_context())) { >> int success = is_syscall_success(pt_regs); > > Since we are shifting to use syscall_get_return_value() below, would > it also make sense to shift to using syscall_get_error() here instead > of is_syscall_success()? In [PATCH v2 1/3], is_syscall_success calls syscall_get_return_value to take care of the sign extension issue. Keeping using is_syscall_success is to not potentially changing other architectures' behavior.