forked from luck/tmp_suning_uos_patched
samples/seccomp: Zero out members based on seccomp_notif_sizes
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>
This commit is contained in:
parent
fd6988496e
commit
771b894f2f
|
@ -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
Block a user