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authorArjan van de Ven <arjan@linux.intel.com>2009-09-26 20:50:25 +0200
committerLen Brown <len.brown@intel.com>2009-10-03 00:59:12 -0400
commitd9f65018065ee1b161a85f54132193f248a45439 (patch)
tree40b3d3f68ee8bc38f6c455c8722c95241690f058
parent0efe5e32c8729ef44b00d9a7203e4c99a6378b27 (diff)
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ACPI: Fix bound checks for copy_from_user in the acpi /proc code
The ACPI /proc write() code takes an unsigned length argument like any write() function, but then assigned it to a *signed* integer called "len". Only after this is a sanity check for len done to make it not larger than 4. Due to the type change a len < 0 is in principle also possible; this patch adds a check for this. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--drivers/acpi/proc.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c
index d0d550d22a6..f8b6f555ba5 100644
--- a/drivers/acpi/proc.c
+++ b/drivers/acpi/proc.c
@@ -398,6 +398,8 @@ acpi_system_write_wakeup_device(struct file *file,
if (len > 4)
len = 4;
+ if (len < 0)
+ return -EFAULT;
if (copy_from_user(strbuf, buffer, len))
return -EFAULT;