From: He Zhe
> Sent: 14 April 2021 09:02
>
> When 32-bit userspace application is running on 64-bit kernel, the 32-bit
> syscall return code would be changed from u32 to u64 in regs_return_value
> and then changed to s64. Hence the negative return code recorded by audit
> would end up being a big positive number like below.
>
> type=SYSCALL msg=audit(1611110715.887:582): arch=40000028 syscall=322
> success=yes exit=4294967283
>
> This patch forces the u32->s32->s64 for compat tasks.
>
> Signed-off-by: He Zhe <zhe...@windriver.com>
> ---
> include/linux/audit.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 82b7c1116a85..32cb853f3029 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -334,7 +334,9 @@ static inline void audit_syscall_exit(void *pt_regs)
> {
> if (unlikely(audit_context())) {
> int success = is_syscall_success(pt_regs);
> - long return_code = regs_return_value(pt_regs);
> + long return_code = is_compat_task() ?
Should that be is_compat_syscall() ?
A x86-64 process can make both types of 32bit system calls.
David
> + (s64)(s32)regs_return_value(pt_regs) :
> + regs_return_value(pt_regs);
>
> __audit_syscall_exit(success, return_code);
> }
> --
> 2.17.1
-
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