Commit-ID: 32043fa065b51e0b1433e48d118821c71b5cd65d
Gitweb: https://git.kernel.org/tip/32043fa065b51e0b1433e48d118821c71b5cd65d
Author: Colin Ian King <[email protected]>
AuthorDate: Tue, 18 Dec 2018 17:29:56 +0000
Committer: Thomas Gleixner <[email protected]>
CommitDate: Wed, 19 Dec 2018 00:00:16 +0100
x86/mtrr: Don't copy uninitialized gentry fields back to userspace
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]
---
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 2e173d47b450..4d36dcc1cf87 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -165,6 +165,8 @@ 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:
