From: Joe Perches joe@perches.com
stable inclusion from linux-4.19.149 commit 489cee9124d53ce20fb3f989449efa2aa51a4b18
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[ Upstream commit 5e1aada08cd19ea652b2d32a250501d09b02ff2e ]
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@perc... 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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/sys.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/sys.c b/kernel/sys.c index 827289a34776..55e142077dcf 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1275,11 +1275,13 @@ 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);