diff options
| author | Jan Beulich <JBeulich@novell.com> | 2009-10-26 15:20:29 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-10-26 16:23:26 +0100 |
| commit | 81766741fe1eee3884219e8daaf03f466f2ed52f (patch) | |
| tree | 0afde40852f608ed101d03a83ef49ef74ccbb434 | |
| parent | 72ed7de74e8f0fad0d8e567ae1f987b740accb3f (diff) | |
x86-64: Fix register leak in 32-bit syscall audting
Restoring %ebp after the call to audit_syscall_exit() is not
only unnecessary (because the register didn't get clobbered),
but in the sysenter case wasn't even doing the right thing: It
loaded %ebp from a location below the top of stack (RBP <
ARGOFFSET), i.e. arbitrary kernel data got passed back to user
mode in the register.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: <stable@kernel.org>
LKML-Reference: <4AE5CC4D020000780001BD13@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/ia32/ia32entry.S | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 1733f9f65e8..581b0568fe1 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -204,7 +204,7 @@ sysexit_from_sys_call: movl RDI-ARGOFFSET(%rsp),%r8d /* reload 5th syscall arg */ .endm - .macro auditsys_exit exit,ebpsave=RBP + .macro auditsys_exit exit testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10) jnz ia32_ret_from_sys_call TRACE_IRQS_ON @@ -217,7 +217,6 @@ sysexit_from_sys_call: call audit_syscall_exit GET_THREAD_INFO(%r10) movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall return value */ - movl \ebpsave-ARGOFFSET(%rsp),%ebp /* reload user register value */ movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi cli TRACE_IRQS_OFF @@ -351,7 +350,7 @@ cstar_auditsys: jmp cstar_dispatch sysretl_audit: - auditsys_exit sysretl_from_sys_call, RCX /* user %ebp in RCX slot */ + auditsys_exit sysretl_from_sys_call #endif cstar_tracesys: |