| From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.14 023/127] kernel/sys.c: avoid copying possible padding bytes in copy_to_user | Date | Thu, 17 Sep 2020 22:10:36 -0400 |
| |
From: Joe Perches <joe@perches.com>
[ 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@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> Signed-off-by: Sasha Levin <sashal@kernel.org> --- kernel/sys.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/sys.c b/kernel/sys.c index ab96b98823473..2e4f017f7c5aa 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1217,11 +1217,13 @@ 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); -- 2.25.1
|