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authorJoe Perches <joe@perches.com>2019-12-05 01:50:53 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-05 04:44:12 +0100
commit5e1aada08cd19ea652b2d32a250501d09b02ff2e (patch)
treeb0722199d6d1f1b432a237e47f02cbb150f89dfa /kernel/sys.c
parentkernel/profile.c: use cpumask_available to check for NULL cpumask (diff)
downloadlinux-5e1aada08cd19ea652b2d32a250501d09b02ff2e.tar.xz
linux-5e1aada08cd19ea652b2d32a250501d09b02ff2e.zip
kernel/sys.c: avoid copying possible padding bytes in copy_to_user
Initialization is not guaranteed to zero padding bytes so use an explicit memset instead to avoid leaking any kernel content in any possible padding bytes. Link: http://lkml.kernel.org/r/dfa331c00881d61c8ee51577a082d8bebd61805c.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Dan Carpenter <error27@gmail.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sys.c')
-rw-r--r--kernel/sys.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index d3aef31e24dc..a9331f101883 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1279,11 +1279,13 @@ SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
{
- struct oldold_utsname tmp = {};
+ struct oldold_utsname tmp;
if (!name)
return -EFAULT;
+ memset(&tmp, 0, sizeof(tmp));
+
down_read(&uts_sem);
memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);