samples/seccomp: Zero out members based on seccomp_notif_sizes
commit5.4-rM2-2.2.x-imx-squashed771b894f2f
upstream. The sizes by which seccomp_notif and seccomp_notif_resp are allocated are based on the SECCOMP_GET_NOTIF_SIZES ioctl. This allows for graceful extension of these datastructures. If userspace zeroes out the datastructure based on its version, and it is lagging behind the kernel's version, it will end up sending trailing garbage. On the other hand, if it is ahead of the kernel version, it will write extra zero space, and potentially cause corruption. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Suggested-by: Tycho Andersen <tycho@tycho.ws> Link: https://lore.kernel.org/r/20191230203503.4925-1-sargun@sargun.me Fixes:fec7b66905
("samples: add an example of seccomp user trap") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
f75e60d239
commit
de7cd9dfc5
|
@ -298,14 +298,14 @@ int main(void)
|
|||
req = malloc(sizes.seccomp_notif);
|
||||
if (!req)
|
||||
goto out_close;
|
||||
memset(req, 0, sizeof(*req));
|
||||
|
||||
resp = malloc(sizes.seccomp_notif_resp);
|
||||
if (!resp)
|
||||
goto out_req;
|
||||
memset(resp, 0, sizeof(*resp));
|
||||
memset(resp, 0, sizes.seccomp_notif_resp);
|
||||
|
||||
while (1) {
|
||||
memset(req, 0, sizes.seccomp_notif);
|
||||
if (ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, req)) {
|
||||
perror("ioctl recv");
|
||||
goto out_resp;
|
||||
|
|
Loading…
Reference in New Issue