git: 32026f5983ed - main - sys_procctl(): zero the data buffer once, on syscall entry

[Konstantin Belousov]

The branch main has been updated by kib:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=32026f5983ed00e64829f8c20b09748077809729

commit 32026f5983ed00e64829f8c20b09748077809729
Author:     Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2021-10-16 18:28:03 +0000
Commit:     Konstantin Belousov <k...@freebsd.org>
CommitDate: 2021-10-19 20:04:34 +0000

    sys_procctl(): zero the data buffer once, on syscall entry
    
    and remove zeroing of it from specific functions.  This way it is
    guaranteed that we do not leak kernel data.
    
    Suggested by:   markj
    Reviewed by:    emaste, markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D32513
---
 sys/kern/kern_procctl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/kern/kern_procctl.c b/sys/kern/kern_procctl.c
index 7a88ef24d987..387706a0cb1e 100644
--- a/sys/kern/kern_procctl.c
+++ b/sys/kern/kern_procctl.c
@@ -171,7 +171,6 @@ reap_status(struct thread *td, struct proc *p, void *data)
 
        rs = data;
        sx_assert(&proctree_lock, SX_LOCKED);
-       bzero(rs, sizeof(*rs));
        if ((p->p_treeflag & P_TREE_REAPER) == 0) {
                reap = p->p_reaper;
        } else {
@@ -850,6 +849,8 @@ sys_procctl(struct thread *td, struct procctl_args *uap)
        if (uap->com == 0 || uap->com >= nitems(procctl_cmds_info))
                return (EINVAL);
        cmd_info = &procctl_cmds_info[uap->com];
+       bzero(&x, sizeof(x));
+
        if (cmd_info->copyin_sz > 0) {
                error = copyin(uap->data, &x, cmd_info->copyin_sz);
                if (error != 0)