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    SubjectRe: [PATCH ghak90 V5 05/10] audit: add containerid support for ptrace and signals
    On Fri, Mar 15, 2019 at 7:34 PM Richard Guy Briggs <rgb@redhat.com> wrote:
    > Add audit container identifier support to ptrace and signals. In
    > particular, the "ref" field provides a way to label the auxiliary record
    > to which it is associated.
    >
    > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
    > Acked-by: Serge Hallyn <serge@hallyn.com>
    > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
    > ---
    > include/linux/audit.h | 1 +
    > kernel/audit.c | 2 ++
    > kernel/audit.h | 2 ++
    > kernel/auditsc.c | 23 +++++++++++++++++------
    > 4 files changed, 22 insertions(+), 6 deletions(-)
    >
    > diff --git a/include/linux/audit.h b/include/linux/audit.h
    > index 43438192ca2a..ebd6625ca80e 100644
    > --- a/include/linux/audit.h
    > +++ b/include/linux/audit.h
    > @@ -35,6 +35,7 @@ struct audit_sig_info {
    > uid_t uid;
    > pid_t pid;
    > char ctx[0];
    > + u64 cid;
    > };

    It seems like this structure implicitly defines the format of some
    message that is sent to userspace... If so, how will userspace detect
    that a new format (including the cid) is being used? Even assuming the
    fixed order as pointed out by Neil, the message still seems to be
    variable-sized so userspace cannot even use the length to infer that.
    Am I missing something here? (I hope I am :)

    >
    > struct audit_buffer;
    > diff --git a/kernel/audit.c b/kernel/audit.c
    > index 8cc0e88d7f2a..cfa659b3f6c4 100644
    > --- a/kernel/audit.c
    > +++ b/kernel/audit.c
    > @@ -138,6 +138,7 @@ struct audit_net {
    > kuid_t audit_sig_uid = INVALID_UID;
    > pid_t audit_sig_pid = -1;
    > u32 audit_sig_sid = 0;
    > +u64 audit_sig_cid = AUDIT_CID_UNSET;
    >
    > /* Records can be lost in several ways:
    > 0) [suppressed in audit_alloc]
    > @@ -1515,6 +1516,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
    > memcpy(sig_data->ctx, ctx, len);
    > security_release_secctx(ctx, len);
    > }
    > + sig_data->cid = audit_sig_cid;
    > audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
    > sig_data, sizeof(*sig_data) + len);
    > kfree(sig_data);
    > diff --git a/kernel/audit.h b/kernel/audit.h
    > index c00e2ee3c6b3..c5ac6436317e 100644
    > --- a/kernel/audit.h
    > +++ b/kernel/audit.h
    > @@ -148,6 +148,7 @@ struct audit_context {
    > kuid_t target_uid;
    > unsigned int target_sessionid;
    > u32 target_sid;
    > + u64 target_cid;
    > char target_comm[TASK_COMM_LEN];
    >
    > struct audit_tree_refs *trees, *first_trees;
    > @@ -344,6 +345,7 @@ extern void audit_filter_inodes(struct task_struct *tsk,
    > extern pid_t audit_sig_pid;
    > extern kuid_t audit_sig_uid;
    > extern u32 audit_sig_sid;
    > +extern u64 audit_sig_cid;
    >
    > extern int audit_filter(int msgtype, unsigned int listtype);
    >
    > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
    > index a8c8b44b954d..f04e115df5dc 100644
    > --- a/kernel/auditsc.c
    > +++ b/kernel/auditsc.c
    > @@ -113,6 +113,7 @@ struct audit_aux_data_pids {
    > kuid_t target_uid[AUDIT_AUX_PIDS];
    > unsigned int target_sessionid[AUDIT_AUX_PIDS];
    > u32 target_sid[AUDIT_AUX_PIDS];
    > + u64 target_cid[AUDIT_AUX_PIDS];
    > char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
    > int pid_count;
    > };
    > @@ -1514,7 +1515,7 @@ static void audit_log_exit(void)
    > for (aux = context->aux_pids; aux; aux = aux->next) {
    > struct audit_aux_data_pids *axs = (void *)aux;
    >
    > - for (i = 0; i < axs->pid_count; i++)
    > + for (i = 0; i < axs->pid_count; i++) {
    > if (audit_log_pid_context(context, axs->target_pid[i],
    > axs->target_auid[i],
    > axs->target_uid[i],
    > @@ -1522,14 +1523,20 @@ static void audit_log_exit(void)
    > axs->target_sid[i],
    > axs->target_comm[i]))
    > call_panic = 1;
    > + audit_log_contid(context, axs->target_cid[i]);
    > + }
    > }
    >
    > - if (context->target_pid &&
    > - audit_log_pid_context(context, context->target_pid,
    > - context->target_auid, context->target_uid,
    > - context->target_sessionid,
    > - context->target_sid, context->target_comm))
    > + if (context->target_pid) {
    > + if (audit_log_pid_context(context, context->target_pid,
    > + context->target_auid,
    > + context->target_uid,
    > + context->target_sessionid,
    > + context->target_sid,
    > + context->target_comm))
    > call_panic = 1;
    > + audit_log_contid(context, context->target_cid);
    > + }
    >
    > if (context->pwd.dentry && context->pwd.mnt) {
    > ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
    > @@ -2360,6 +2367,7 @@ void __audit_ptrace(struct task_struct *t)
    > context->target_uid = task_uid(t);
    > context->target_sessionid = audit_get_sessionid(t);
    > security_task_getsecid(t, &context->target_sid);
    > + context->target_cid = audit_get_contid(t);
    > memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
    > }
    >
    > @@ -2387,6 +2395,7 @@ int audit_signal_info(int sig, struct task_struct *t)
    > else
    > audit_sig_uid = uid;
    > security_task_getsecid(current, &audit_sig_sid);
    > + audit_sig_cid = audit_get_contid(current);
    > }
    >
    > if (!audit_signals || audit_dummy_context())
    > @@ -2400,6 +2409,7 @@ int audit_signal_info(int sig, struct task_struct *t)
    > ctx->target_uid = t_uid;
    > ctx->target_sessionid = audit_get_sessionid(t);
    > security_task_getsecid(t, &ctx->target_sid);
    > + ctx->target_cid = audit_get_contid(t);
    > memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
    > return 0;
    > }
    > @@ -2421,6 +2431,7 @@ int audit_signal_info(int sig, struct task_struct *t)
    > axp->target_uid[axp->pid_count] = t_uid;
    > axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
    > security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
    > + axp->target_cid[axp->pid_count] = audit_get_contid(t);
    > memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
    > axp->pid_count++;
    >
    > --
    > 1.8.3.1
    >


    --
    Ondrej Mosnacek <omosnace at redhat dot com>
    Software Engineer, Security Technologies
    Red Hat, Inc.

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