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 - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)