* [PATCH] SGI UV: uv_ptc_proc_write security hole
@ 2008-06-23 13:32 Cliff Wickman
2008-06-23 21:13 ` Ingo Molnar
0 siblings, 1 reply; 2+ messages in thread
From: Cliff Wickman @ 2008-06-23 13:32 UTC (permalink / raw)
To: mingo; +Cc: linux-kernel
From: Cliff Wickman <cpw@sgi.com>
Someone could write 0 bytes to /proc/sgi_uv/ptc_statistics,
causing
optstr[count - 1] = '\0';
to write to who-knows-where.
(Andi Kleen noticed this need from a patch I sent for
similar code in the ia64 world (sn2_ptc_proc_write()).)
(count less than zero is not possible here, as count is unsigned)
Diffed against 2.6.26-rc6
Signed-off-by: Cliff Wickman <cpw@sgi.com>
---
arch/x86/kernel/tlb_uv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux/arch/x86/kernel/tlb_uv.c
===================================================================
--- linux.orig/arch/x86/kernel/tlb_uv.c
+++ linux/arch/x86/kernel/tlb_uv.c
@@ -492,7 +492,7 @@ static ssize_t uv_ptc_proc_write(struct
long newmode;
char optstr[64];
- if (count > 64)
+ if (count == 0 || count > sizeof(optstr))
return -EINVAL;
if (copy_from_user(optstr, user, count))
return -EFAULT;
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] SGI UV: uv_ptc_proc_write security hole
2008-06-23 13:32 [PATCH] SGI UV: uv_ptc_proc_write security hole Cliff Wickman
@ 2008-06-23 21:13 ` Ingo Molnar
0 siblings, 0 replies; 2+ messages in thread
From: Ingo Molnar @ 2008-06-23 21:13 UTC (permalink / raw)
To: Cliff Wickman; +Cc: linux-kernel
* Cliff Wickman <cpw@sgi.com> wrote:
> From: Cliff Wickman <cpw@sgi.com>
>
> Someone could write 0 bytes to /proc/sgi_uv/ptc_statistics,
> causing
> optstr[count - 1] = '\0';
> to write to who-knows-where.
>
> (Andi Kleen noticed this need from a patch I sent for
> similar code in the ia64 world (sn2_ptc_proc_write()).)
>
> (count less than zero is not possible here, as count is unsigned)
>
> Diffed against 2.6.26-rc6
applied to tip/x86/uv - thanks Cliff.
Ingo
^ permalink raw reply [flat|nested] 2+ messages in thread
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2008-06-23 13:32 [PATCH] SGI UV: uv_ptc_proc_write security hole Cliff Wickman
2008-06-23 21:13 ` Ingo Molnar
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