From: Colin Ian King <[email protected]>
[ Upstream commit 32043fa065b51e0b1433e48d118821c71b5cd65d ]
Currently the copy_to_user of data in the gentry struct is copying
uninitiaized data in field _pad from the stack to userspace.
Fix this by explicitly memset'ing gentry to zero, this also will zero any
compiler added padding fields that may be in struct (currently there are
none).
Detected by CoverityScan, CID#200783 ("Uninitialized scalar variable")
Fixes: b263b31e8ad6 ("x86, mtrr: Use explicit sizing and padding for the 64-bit
ioctls")
Signed-off-by: Colin Ian King <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Tyler Hicks <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
---
arch/x86/kernel/cpu/mtrr/if.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 6d9b45549109..d5b2a08e2b66 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -172,6 +172,8 @@ mtrr_ioctl(struct file *file, unsigned int cmd, unsigned
long __arg)
struct mtrr_gentry gentry;
void __user *arg = (void __user *) __arg;
+ memset(&gentry, 0, sizeof(gentry));
+
switch (cmd) {
case MTRRIOC_ADD_ENTRY:
case MTRRIOC_SET_ENTRY:
--
2.19.1
