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TritonDataCenter#366 LX libaudit clients cause kernel memory usage to…
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TritonDataCenter#367 LX libaudit wants LX_AUDIT_USER
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@arekinath
arekinath committed May 16, 2022
1 parent 8488322 commit 2cc256d
Showing 1 changed file with 104 additions and 51 deletions.
155 changes: 104 additions & 51 deletions usr/src/uts/common/brand/lx/io/lx_netlink.c
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Original file line number Diff line number Diff line change
Expand Up @@ -302,6 +302,7 @@
*/
#define LX_AUDIT_GET 1000 /* get audit system status */
#define LX_AUDIT_SET 1001 /* set audit system status */
#define LX_AUDIT_USER 1005
#define LX_AUDIT_WATCH_INS 1007 /* insert file watch */
#define LX_AUDIT_WATCH_REM 1008 /* remove file watch */
#define LX_AUDIT_WATCH_LIST 1009 /* list file watchs */
Expand Down Expand Up @@ -862,11 +863,35 @@ lx_netlink_reply_sendup(lx_netlink_reply_t *reply, mblk_t *mp, mblk_t *mp1)
*/
mp1->b_cont = mp;

/*
* If the socket is currently flow-controlled, do not allow further
* data to be sent out.
*/
mutex_enter(&lxsock->lxns_flowctl_mtx);
if (lxsock->lxns_flowctrled) {
mutex_exit(&lxsock->lxns_flowctl_mtx);
freemsg(mp1);
return;
}

lxsock->lxns_upcalls->su_recv(lxsock->lxns_uphandle, mp1,
msgdsize(mp1), 0, &error, NULL);

if (error != 0)
/*
* The socket indicated that it is now flow-controlled. That said, it
* still queued the last message, so indicated success (but track the
* flow-controlled state).
*/
if (error == ENOSPC) {
lxsock->lxns_flowctrled = B_TRUE;
lx_netlink_flowctrld++;
error = 0;
}
mutex_exit(&lxsock->lxns_flowctl_mtx);

if (error != 0) {
/* XXX: maybe print an error to dmesg? idk */
}
}

static void
Expand All @@ -886,67 +911,94 @@ lx_netlink_reply_send(lx_netlink_reply_t *reply)
reply->lxnr_mp = NULL;
}

/*
* Reply with an NLMSG_ERROR, even if errno is 0. This is used by several
* audit functions where Linux libaudit refuses to correctly handle our usual
* multi-part replies (with NLM_F_MULTI set).
*
* lx_netlink_au_um also calls this to generate an ACK message.
*/
static void
lx_netlink_reply_done(lx_netlink_reply_t *reply)
lx_netlink_reply_error_done(lx_netlink_reply_t *reply)
{
lx_netlink_sock_t *lxsock = reply->lxnr_sock;
mblk_t *mp;
lx_netlink_hdr_t *hdr;
lx_netlink_err_t *err;

/*
* Denote that we're done via a message with a NULL payload.
*/
lx_netlink_reply_msg(reply, NULL, 0);

if (reply->lxnr_errno) {
/*
* If anything failed, we'll send up an error message.
*/
lx_netlink_hdr_t *hdr;
lx_netlink_err_t *err;
if (reply->lxnr_mp != NULL) {
freeb(reply->lxnr_mp);
reply->lxnr_mp = NULL;
}

if (reply->lxnr_mp != NULL) {
freeb(reply->lxnr_mp);
reply->lxnr_mp = NULL;
}
mp = reply->lxnr_err;
VERIFY(mp != NULL);
reply->lxnr_err = NULL;
err = (lx_netlink_err_t *)mp->b_rptr;
hdr = &err->lxne_hdr;
mp->b_wptr += sizeof (lx_netlink_err_t);

mp = reply->lxnr_err;
VERIFY(mp != NULL);
reply->lxnr_err = NULL;
err = (lx_netlink_err_t *)mp->b_rptr;
hdr = &err->lxne_hdr;
mp->b_wptr += sizeof (lx_netlink_err_t);

err->lxne_failed = reply->lxnr_hdr;
err->lxne_errno = reply->lxnr_errno;
hdr->lxnh_type = LX_NETLINK_NLMSG_ERROR;
hdr->lxnh_seq = reply->lxnr_hdr.lxnh_seq;
hdr->lxnh_len = sizeof (lx_netlink_err_t);
hdr->lxnh_seq = reply->lxnr_hdr.lxnh_seq;
hdr->lxnh_pid = lxsock->lxns_port;
hdr->lxnh_flags = 0;
} else {
uint32_t status = 0;
err->lxne_failed = reply->lxnr_hdr;
err->lxne_errno = reply->lxnr_errno;
hdr->lxnh_type = LX_NETLINK_NLMSG_ERROR;
hdr->lxnh_seq = reply->lxnr_hdr.lxnh_seq;
hdr->lxnh_len = sizeof (lx_netlink_err_t);
hdr->lxnh_seq = reply->lxnr_hdr.lxnh_seq;
hdr->lxnh_pid = lxsock->lxns_port;
hdr->lxnh_flags = 0;

/*
* More recent versions of the iproute2 utils expect a status
* value after the header, even in the absence of errors.
*/
lx_netlink_reply_add(reply, &status, sizeof (status));
lx_netlink_reply_sendup(reply, mp, reply->lxnr_mp1);

/*
* "done" is also the most minimal response possible. If
* lx_netlink_reply_msg() does not set lxnr_errno, we should
* be guaranteed enough room to hold this (i.e. our
* lx_netlink_reply_add() call should never end up setting
* lxnr_errno).
*/
VERIFY0(reply->lxnr_errno);
if (reply->lxnr_mp != NULL)
freeb(reply->lxnr_mp);

mp = reply->lxnr_mp;
VERIFY(mp != NULL);
reply->lxnr_mp = NULL;
if (reply->lxnr_err != NULL)
freeb(reply->lxnr_err);

kmem_free(reply, sizeof (lx_netlink_reply_t));
}

static void
lx_netlink_reply_done(lx_netlink_reply_t *reply)
{
lx_netlink_sock_t *lxsock = reply->lxnr_sock;
mblk_t *mp;
uint32_t status = 0;

if (reply->lxnr_errno) {
lx_netlink_reply_error_done(reply);
return;
}

/*
* Denote that we're done via a message with a NULL payload.
*/
lx_netlink_reply_msg(reply, NULL, 0);

/*
* More recent versions of the iproute2 utils expect a status
* value after the header, even in the absence of errors.
*/
lx_netlink_reply_add(reply, &status, sizeof (status));

/*
* "done" is also the most minimal response possible. If
* lx_netlink_reply_msg() does not set lxnr_errno, we should
* be guaranteed enough room to hold this (i.e. our
* lx_netlink_reply_add() call should never end up setting
* lxnr_errno).
*/
VERIFY0(reply->lxnr_errno);

mp = reply->lxnr_mp;
VERIFY(mp != NULL);
reply->lxnr_mp = NULL;

lx_netlink_reply_sendup(reply, mp, reply->lxnr_mp1);

if (reply->lxnr_mp != NULL)
Expand All @@ -972,7 +1024,7 @@ lx_netlink_reply_error(lx_netlink_sock_t *lxsock,
return (ENOMEM);

reply->lxnr_errno = errno;
lx_netlink_reply_done(reply);
lx_netlink_reply_error_done(reply);

return (0);
}
Expand Down Expand Up @@ -1642,7 +1694,7 @@ lx_netlink_au_set(lx_netlink_sock_t *lxsock, lx_netlink_hdr_t *hdr, mblk_t *mp)
if (reply == NULL)
return (ENOMEM);

lx_netlink_reply_done(reply);
lx_netlink_reply_error_done(reply);
return (0);
}

Expand Down Expand Up @@ -1676,7 +1728,7 @@ lx_netlink_au_ar(lx_netlink_sock_t *lxsock, lx_netlink_hdr_t *hdr, mblk_t *mp)
if (reply == NULL)
return (ENOMEM);

lx_netlink_reply_done(reply);
lx_netlink_reply_error_done(reply);
return (0);
}

Expand Down Expand Up @@ -1710,7 +1762,7 @@ lx_netlink_au_dr(lx_netlink_sock_t *lxsock, lx_netlink_hdr_t *hdr, mblk_t *mp)
if (reply == NULL)
return (ENOMEM);

lx_netlink_reply_done(reply);
lx_netlink_reply_error_done(reply);
return (0);
}

Expand Down Expand Up @@ -1793,7 +1845,7 @@ lx_netlink_au_um(lx_netlink_sock_t *lxsock, lx_netlink_hdr_t *hdr, mblk_t *mp)
if (reply == NULL)
return (ENOMEM);

lx_netlink_reply_done(reply);
lx_netlink_reply_error_done(reply);
}
return (0);
}
Expand Down Expand Up @@ -1906,7 +1958,8 @@ lx_netlink_audit(lx_netlink_sock_t *lxsock, lx_netlink_hdr_t *hdr, mblk_t *mp)
* }
*/

if (hdr->lxnh_type >= LX_AUDIT_USER_MSG_START) {
if (hdr->lxnh_type == LX_AUDIT_USER ||
hdr->lxnh_type >= LX_AUDIT_USER_MSG_START) {
return (lx_netlink_au_um(lxsock, hdr, mp));
}

Expand Down

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