This is a note to let you know that I've just added the patch titled
s390/syscalls: Fix out of bounds arguments access
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-syscalls-fix-out-of-bounds-arguments-access.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c46fc0424ced3fb71208e72bd597d91b9169a781 Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@xxxxxxxxxx>
Date: Thu, 29 Jun 2017 11:38:11 +0200
Subject: s390/syscalls: Fix out of bounds arguments access
From: Jiri Olsa <jolsa@xxxxxxxxxx>
commit c46fc0424ced3fb71208e72bd597d91b9169a781 upstream.
Zorro reported following crash while having enabled
syscall tracing (CONFIG_FTRACE_SYSCALLS):
Unable to handle kernel pointer dereference at virtual ...
Oops: 0011 [#1] SMP DEBUG_PAGEALLOC
SNIP
Call Trace:
([<000000000024d79c>] ftrace_syscall_enter+0xec/0x1d8)
[<00000000001099c6>] do_syscall_trace_enter+0x236/0x2f8
[<0000000000730f1c>] sysc_tracesys+0x1a/0x32
[<000003fffcf946a2>] 0x3fffcf946a2
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<000000000022dd44>] rb_event_data+0x34/0x40
---[ end trace 8c795f86b1b3f7b9 ]---
The crash happens in syscall_get_arguments function for
syscalls with zero arguments, that will try to access
first argument (args[0]) in event entry, but it's not
allocated.
Bail out of there are no arguments.
Reported-by: Zorro Lang <zlang@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/include/asm/syscall.h | 6 ++++++
1 file changed, 6 insertions(+)
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -64,6 +64,12 @@ static inline void syscall_get_arguments
{
unsigned long mask = -1UL;
+ /*
+ * No arguments for this syscall, there's nothing to do.
+ */
+ if (!n)
+ return;
+
BUG_ON(i + n > 6);
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT))
Patches currently in stable-queue which might be from jolsa@xxxxxxxxxx are
queue-4.9/s390-syscalls-fix-out-of-bounds-arguments-access.patch