diff options
| author | Andy Lutomirski <luto@amacapital.net> | 2014-06-23 14:22:15 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2014-11-23 10:55:31 +0100 |
| commit | 561ca83b38ce42113f64240ddb01ac6545ad0705 (patch) | |
| tree | 49058c7d262cb4a7f3237631d854448438db9dc0 | |
| parent | 02560982919d795e0f27167e254c767d3e66e442 (diff) | |
x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508)
The bad syscall nr paths are their own incomprehensible route
through the entry control flow. Rearrange them to work just like
syscalls that return -ENOSYS.
This fixes an OOPS in the audit code when fast-path auditing is
enabled and sysenter gets a bad syscall nr (CVE-2014-4508).
This has probably been broken since Linux 2.6.27:
af0575bba0 i386 syscall audit fast-path
Cc: stable@vger.kernel.org
Cc: Roland McGrath <roland@redhat.com>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e09c499eade6fc321266dd6b54da7beb28d6991c.1403558229.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
(cherry picked from commit 554086d85e71f30abe46fc014fea31929a7c6a8a)
[WT: this fix is incorrect and requires the two following patches]
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | arch/x86/kernel/entry_32.S | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index c097e7d607c6..40a0d028d2b7 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -445,9 +445,10 @@ sysenter_past_esp: jnz sysenter_audit sysenter_do_call: cmpl $(nr_syscalls), %eax - jae syscall_badsys + jae sysenter_badsys call *sys_call_table(,%eax,4) movl %eax,PT_EAX(%esp) +sysenter_after_call: LOCKDEP_SYS_EXIT DISABLE_INTERRUPTS(CLBR_ANY) TRACE_IRQS_OFF @@ -702,7 +703,12 @@ END(syscall_fault) syscall_badsys: movl $-ENOSYS,PT_EAX(%esp) - jmp resume_userspace + jmp syscall_exit +END(syscall_badsys) + +sysenter_badsys: + movl $-ENOSYS,PT_EAX(%esp) + jmp sysenter_after_call END(syscall_badsys) CFI_ENDPROC |