x86, SGI UV: TLB shootdown using broadcast assist unit, v6
v6: 6/19 close the security hole in uv_ptc_proc_write())
> Found a potential security hole while doing that:
> static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user,
> size_t count, loff_t *data)
> if (copy_from_user(optstr, user, count))
> return -EFAULT;
>
> is count guaranteed to never be larger than 64?
is fixed below.
It adds tlb_uv.o to the Makefile.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: mingo@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
index b362913..c503b7f 100644
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -492,6 +492,8 @@
long newmode;
char optstr[64];
+ if (count > 64)
+ return -EINVAL;
if (copy_from_user(optstr, user, count))
return -EFAULT;
optstr[count - 1] = '\0';