[PATCH linux-stable 6.6] Bluetooth: hci_conn: avoid queue when deleting hci connection

[PATCH linux-stable 6.6] Bluetooth: hci_conn: avoid queue when deleting hci connection

[xu.xin16]

From: Chen Junlin <chen.junlin@zte.com.cn>

Although the upstream commit 2b0f2fc9ed62 ("Bluetooth: hci_conn:
Use disable_delayed_work_sync") has fixed the issue CVE-2024-56591, that
patch depends on the implementaion of disable/enable_work() of workqueue
[1], which are merged into 6.9/6.10 and so on. But for branch linux-6.6,
there&apos;s no these feature of workqueue.

To solve CVE-2024-56591 without backport too many feature patches about
workqueue, we can set a new flag HCI_CONN_DELETE when hci_conn_dell() is
called, and the subsequent queuing of work will be ignored.

[1] https://lore.kernel.org/all/20240216180559.208276-1-tj@kernel.org/

Signed-off-by: Chen Junlin <chen.junlin@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
---
include/net/bluetooth/hci_core.h | 8 +++++++-
net/bluetooth/hci_conn.c         | 1 +
2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 4f067599e6e9..9a3ec55079a1 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -954,6 +954,7 @@ enum {
 	HCI_CONN_BIG_SYNC_FAILED,
 	HCI_CONN_PA_SYNC,
 	HCI_CONN_PA_SYNC_FAILED,
+	HCI_CONN_DELETE,
};

static inline bool hci_conn_ssp_enabled(struct hci_conn *conn)
@@ -1575,7 +1576,12 @@ static inline void hci_conn_drop(struct hci_conn *conn)
 		}

 		cancel_delayed_work(&conn->disc_work);
-		queue_delayed_work(conn->hdev->workqueue,
+		/*
+		 * When HCI_CONN_DELETE is set, the conn is goint to be freed.
+		 * Don&apos;t queue the work to avoid noisy WARNing about refcnt < 0.
+		 */
+		if (!test_bit(HCI_CONN_DELETE, &conn->flags))
+			queue_delayed_work(conn->hdev->workqueue,
 				&conn->disc_work, timeo);
 	}
}
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 549ee9e87d63..67a6513bb01c 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1112,6 +1112,7 @@ void hci_conn_del(struct hci_conn *conn)

 	hci_conn_unlink(conn);

+	set_bit(HCI_CONN_DELETE, &conn->flags);
 	cancel_delayed_work_sync(&conn->disc_work);
 	cancel_delayed_work_sync(&conn->auto_accept_work);
 	cancel_delayed_work_sync(&conn->idle_work);
--
2.15.2

Re: [PATCH linux-stable 6.6] Bluetooth: hci_conn: avoid queue when deleting hci connection

[Greg KH]

On Tue, Aug 19, 2025 at 10:16:05PM +0800, xu.xin16@zte.com.cn wrote:
> From: Chen Junlin <chen.junlin@zte.com.cn>
> 
> Although the upstream commit 2b0f2fc9ed62 ("Bluetooth: hci_conn:
> Use disable_delayed_work_sync") has fixed the issue CVE-2024-56591, that
> patch depends on the implementaion of disable/enable_work() of workqueue
> [1], which are merged into 6.9/6.10 and so on. But for branch linux-6.6,
> there&apos;s no these feature of workqueue.

html marker in a changelog text?

> To solve CVE-2024-56591 without backport too many feature patches about
> workqueue, we can set a new flag HCI_CONN_DELETE when hci_conn_dell() is
> called, and the subsequent queuing of work will be ignored.

How was this tested?

> 
> [1] https://lore.kernel.org/all/20240216180559.208276-1-tj@kernel.org/
> 
> Signed-off-by: Chen Junlin <chen.junlin@zte.com.cn>
> Signed-off-by: xu xin <xu.xin16@zte.com.cn>

What commit id does this fix?  Why only 6.6 for it?


> ---
> include/net/bluetooth/hci_core.h | 8 +++++++-
> net/bluetooth/hci_conn.c         | 1 +
> 2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 4f067599e6e9..9a3ec55079a1 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -954,6 +954,7 @@ enum {
>  	HCI_CONN_BIG_SYNC_FAILED,
>  	HCI_CONN_PA_SYNC,
>  	HCI_CONN_PA_SYNC_FAILED,
> +	HCI_CONN_DELETE,
> };
> 
> static inline bool hci_conn_ssp_enabled(struct hci_conn *conn)
> @@ -1575,7 +1576,12 @@ static inline void hci_conn_drop(struct hci_conn *conn)
>  		}
> 
>  		cancel_delayed_work(&conn->disc_work);
> -		queue_delayed_work(conn->hdev->workqueue,
> +		/*
> +		 * When HCI_CONN_DELETE is set, the conn is goint to be freed.
> +		 * Don&apos;t queue the work to avoid noisy WARNing about refcnt < 0.

Again, html text in a comment?

How does that happen?

thanks,

greg k-h

答复: [PATCH linux-stable 6.6] Bluetooth: hci_conn: avoid queue when deleting hci connection

[xu.xin16]

> > From: Chen Junlin <chen.junlin@zte.com.cn>
> > 
> > Although the upstream commit 2b0f2fc9ed62 ("Bluetooth: hci_conn:
> > Use disable_delayed_work_sync") has fixed the issue CVE-2024-56591, that
> > patch depends on the implementaion of disable/enable_work() of workqueue
> > [1], which are merged into 6.9/6.10 and so on. But for branch linux-6.6,
> > there&apos;s no these feature of workqueue.
> 
> html marker in a changelog text?

Oh, sorry, it was a mistake of my editor setting.

> 
> > To solve CVE-2024-56591 without backport too many feature patches about
> > workqueue, we can set a new flag HCI_CONN_DELETE when hci_conn_dell() is
> > called, and the subsequent queuing of work will be ignored.
> 
> How was this tested?

The issue could be reproduce by syzkaller (https://github.com/google/syzkaller)
and the C producer is shown at the last of the reply.

> 
> > 
> > [1] https://lore.kernel.org/all/20240216180559.208276-1-tj@kernel.org/
> > 
> > Signed-off-by: Chen Junlin <chen.junlin@zte.com.cn>
> > Signed-off-by: xu xin <xu.xin16@zte.com.cn>
> 
> What commit id does this fix?  Why only 6.6 for it?

I think the issue have existed for a long time, because it was reproduced even in Linux 5.10,
But I'm not sure which commit cause this. Maybe Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
know better than me.

> 
> 
> > ---
> > include/net/bluetooth/hci_core.h | 8 +++++++-
> > net/bluetooth/hci_conn.c         | 1 +
> > 2 files changed, 8 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> > index 4f067599e6e9..9a3ec55079a1 100644
> > --- a/include/net/bluetooth/hci_core.h
> > +++ b/include/net/bluetooth/hci_core.h
> > @@ -954,6 +954,7 @@ enum {
> >  	HCI_CONN_BIG_SYNC_FAILED,
> >  	HCI_CONN_PA_SYNC,
> >  	HCI_CONN_PA_SYNC_FAILED,
> > +	HCI_CONN_DELETE,
> > };
> > 
> > static inline bool hci_conn_ssp_enabled(struct hci_conn *conn)
> > @@ -1575,7 +1576,12 @@ static inline void hci_conn_drop(struct hci_conn *conn)
> >  		}
> > 
> >  		cancel_delayed_work(&conn->disc_work);
> > -		queue_delayed_work(conn->hdev->workqueue,
> > +		/*
> > +		 * When HCI_CONN_DELETE is set, the conn is goint to be freed.
> > +		 * Don&apos;t queue the work to avoid noisy WARNing about refcnt < 0.
> 
> Again, html text in a comment?
> 
> How does that happen?
> 
> thanks,
> 
> greg k-h
C reproducer:
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE 

#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <sched.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <unistd.h>

#include <linux/capability.h>
#include <linux/rfkill.h>

static bool write_file(const char* file, const char* what, ...)
{
	char buf[1024];
	va_list args;
	va_start(args, what);
	vsnprintf(buf, sizeof(buf), what, args);
	va_end(args);
	buf[sizeof(buf) - 1] = 0;
	int len = strlen(buf);
	int fd = open(file, O_WRONLY | O_CLOEXEC);
	if (fd == -1)
		return false;
	if (write(fd, buf, len) != len) {
		int err = errno;
		close(fd);
		errno = err;
		return false;
	}
	close(fd);
	return true;
}

#define BTPROTO_HCI 1
#define ACL_LINK 1
#define SCAN_PAGE 2

typedef struct {
	uint8_t b[6];
} __attribute__((packed)) bdaddr_t;

#define HCI_COMMAND_PKT 1
#define HCI_EVENT_PKT 4
#define HCI_VENDOR_PKT 0xff

struct hci_command_hdr {
	uint16_t opcode;
	uint8_t plen;
} __attribute__((packed));

struct hci_event_hdr {
	uint8_t evt;
	uint8_t plen;
} __attribute__((packed));

#define HCI_EV_CONN_COMPLETE 0x03
struct hci_ev_conn_complete {
	uint8_t status;
	uint16_t handle;
	bdaddr_t bdaddr;
	uint8_t link_type;
	uint8_t encr_mode;
} __attribute__((packed));

#define HCI_EV_CONN_REQUEST 0x04
struct hci_ev_conn_request {
	bdaddr_t bdaddr;
	uint8_t dev_class[3];
	uint8_t link_type;
} __attribute__((packed));

#define HCI_EV_REMOTE_FEATURES 0x0b
struct hci_ev_remote_features {
	uint8_t status;
	uint16_t handle;
	uint8_t features[8];
} __attribute__((packed));

#define HCI_EV_CMD_COMPLETE 0x0e
struct hci_ev_cmd_complete {
	uint8_t ncmd;
	uint16_t opcode;
} __attribute__((packed));

#define HCI_OP_WRITE_SCAN_ENABLE 0x0c1a

#define HCI_OP_READ_BUFFER_SIZE 0x1005
struct hci_rp_read_buffer_size {
	uint8_t status;
	uint16_t acl_mtu;
	uint8_t sco_mtu;
	uint16_t acl_max_pkt;
	uint16_t sco_max_pkt;
} __attribute__((packed));

#define HCI_OP_READ_BD_ADDR 0x1009
struct hci_rp_read_bd_addr {
	uint8_t status;
	bdaddr_t bdaddr;
} __attribute__((packed));

#define HCI_EV_LE_META 0x3e
struct hci_ev_le_meta {
	uint8_t subevent;
} __attribute__((packed));

#define HCI_EV_LE_CONN_COMPLETE 0x01
struct hci_ev_le_conn_complete {
	uint8_t status;
	uint16_t handle;
	uint8_t role;
	uint8_t bdaddr_type;
	bdaddr_t bdaddr;
	uint16_t interval;
	uint16_t latency;
	uint16_t supervision_timeout;
	uint8_t clk_accurancy;
} __attribute__((packed));

struct hci_dev_req {
	uint16_t dev_id;
	uint32_t dev_opt;
};

struct vhci_vendor_pkt_request {
	uint8_t type;
	uint8_t opcode;
} __attribute__((packed));

struct vhci_pkt {
	uint8_t type;
	union {
		struct {
			uint8_t opcode;
			uint16_t id;
		} __attribute__((packed)) vendor_pkt;
		struct hci_command_hdr command_hdr;
	};
} __attribute__((packed));

#define HCIDEVUP _IOW('H', 201, int)
#define HCISETSCAN _IOW('H', 221, int)

static int vhci_fd = -1;

static void rfkill_unblock_all()
{
	int fd = open("/dev/rfkill", O_WRONLY);
	if (fd < 0)
	exit(1);
	struct rfkill_event event = {0};
	event.idx = 0;
	event.type = RFKILL_TYPE_ALL;
	event.op = RFKILL_OP_CHANGE_ALL;
	event.soft = 0;
	event.hard = 0;
	if (write(fd, &event, sizeof(event)) < 0)
	exit(1);
	close(fd);
}

static void hci_send_event_packet(int fd, uint8_t evt, void* data, size_t data_len)
{
	struct iovec iv[3];
	struct hci_event_hdr hdr;
	hdr.evt = evt;
	hdr.plen = data_len;
	uint8_t type = HCI_EVENT_PKT;
	iv[0].iov_base = &type;
	iv[0].iov_len = sizeof(type);
	iv[1].iov_base = &hdr;
	iv[1].iov_len = sizeof(hdr);
	iv[2].iov_base = data;
	iv[2].iov_len = data_len;
	if (writev(fd, iv, sizeof(iv) / sizeof(struct iovec)) < 0)
	exit(1);
}

static void hci_send_event_cmd_complete(int fd, uint16_t opcode, void* data, size_t data_len)
{
	struct iovec iv[4];
	struct hci_event_hdr hdr;
	hdr.evt = HCI_EV_CMD_COMPLETE;
	hdr.plen = sizeof(struct hci_ev_cmd_complete) + data_len;
	struct hci_ev_cmd_complete evt_hdr;
	evt_hdr.ncmd = 1;
	evt_hdr.opcode = opcode;
	uint8_t type = HCI_EVENT_PKT;
	iv[0].iov_base = &type;
	iv[0].iov_len = sizeof(type);
	iv[1].iov_base = &hdr;
	iv[1].iov_len = sizeof(hdr);
	iv[2].iov_base = &evt_hdr;
	iv[2].iov_len = sizeof(evt_hdr);
	iv[3].iov_base = data;
	iv[3].iov_len = data_len;
	if (writev(fd, iv, sizeof(iv) / sizeof(struct iovec)) < 0)
	exit(1);
}

static bool process_command_pkt(int fd, char* buf, ssize_t buf_size)
{
	struct hci_command_hdr* hdr = (struct hci_command_hdr*)buf;
	if (buf_size < (ssize_t)sizeof(struct hci_command_hdr) ||
	    hdr->plen != buf_size - sizeof(struct hci_command_hdr))
	exit(1);
	switch (hdr->opcode) {
	case HCI_OP_WRITE_SCAN_ENABLE: {
		uint8_t status = 0;
		hci_send_event_cmd_complete(fd, hdr->opcode, &status, sizeof(status));
		return true;
	}
	case HCI_OP_READ_BD_ADDR: {
		struct hci_rp_read_bd_addr rp = {0};
		rp.status = 0;
		memset(&rp.bdaddr, 0xaa, 6);
		hci_send_event_cmd_complete(fd, hdr->opcode, &rp, sizeof(rp));
		return false;
	}
	case HCI_OP_READ_BUFFER_SIZE: {
		struct hci_rp_read_buffer_size rp = {0};
		rp.status = 0;
		rp.acl_mtu = 1021;
		rp.sco_mtu = 96;
		rp.acl_max_pkt = 4;
		rp.sco_max_pkt = 6;
		hci_send_event_cmd_complete(fd, hdr->opcode, &rp, sizeof(rp));
		return false;
	}
	}
	char dummy[0xf9] = {0};
	hci_send_event_cmd_complete(fd, hdr->opcode, dummy, sizeof(dummy));
	return false;
}

static void* event_thread(void* arg)
{
	while (1) {
		char buf[1024] = {0};
		ssize_t buf_size = read(vhci_fd, buf, sizeof(buf));
		if (buf_size < 0)
	exit(1);
		if (buf_size > 0 && buf[0] == HCI_COMMAND_PKT) {
			if (process_command_pkt(vhci_fd, buf + 1, buf_size - 1))
				break;
		}
	}
	return NULL;
}
#define HCI_HANDLE_1 200
#define HCI_HANDLE_2 201

#define HCI_PRIMARY 0
#define HCI_OP_RESET 0x0c03

static void initialize_vhci()
{
	int hci_sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
	if (hci_sock < 0)
	exit(1);
	vhci_fd = open("/dev/vhci", O_RDWR);
	if (vhci_fd == -1)
	exit(1);
	const int kVhciFd = 202;
	if (dup2(vhci_fd, kVhciFd) < 0)
	exit(1);
	close(vhci_fd);
	vhci_fd = kVhciFd;
	struct vhci_vendor_pkt_request vendor_pkt_req = {HCI_VENDOR_PKT, HCI_PRIMARY};
	if (write(vhci_fd, &vendor_pkt_req, sizeof(vendor_pkt_req)) != sizeof(vendor_pkt_req))
	exit(1);
	struct vhci_pkt vhci_pkt;
	if (read(vhci_fd, &vhci_pkt, sizeof(vhci_pkt)) != sizeof(vhci_pkt))
	exit(1);
	if (vhci_pkt.type == HCI_COMMAND_PKT && vhci_pkt.command_hdr.opcode == HCI_OP_RESET) {
		char response[1] = {0};
		hci_send_event_cmd_complete(vhci_fd, HCI_OP_RESET, response, sizeof(response));
		if (read(vhci_fd, &vhci_pkt, sizeof(vhci_pkt)) != sizeof(vhci_pkt))
	exit(1);
	}
	if (vhci_pkt.type != HCI_VENDOR_PKT)
	exit(1);
	int dev_id = vhci_pkt.vendor_pkt.id;
	pthread_t th;
	if (pthread_create(&th, NULL, event_thread, NULL))
	exit(1);
	int ret = ioctl(hci_sock, HCIDEVUP, dev_id);
	if (ret) {
		if (errno == ERFKILL) {
			rfkill_unblock_all();
			ret = ioctl(hci_sock, HCIDEVUP, dev_id);
		}
		if (ret && errno != EALREADY)
	exit(1);
	}
	struct hci_dev_req dr = {0};
	dr.dev_id = dev_id;
	dr.dev_opt = SCAN_PAGE;
	if (ioctl(hci_sock, HCISETSCAN, &dr))
	exit(1);
	struct hci_ev_conn_request request;
	memset(&request, 0, sizeof(request));
	memset(&request.bdaddr, 0xaa, 6);
	*(uint8_t*)&request.bdaddr.b[5] = 0x10;
	request.link_type = ACL_LINK;
	hci_send_event_packet(vhci_fd, HCI_EV_CONN_REQUEST, &request, sizeof(request));
	struct hci_ev_conn_complete complete;
	memset(&complete, 0, sizeof(complete));
	complete.status = 0;
	complete.handle = HCI_HANDLE_1;
	memset(&complete.bdaddr, 0xaa, 6);
	*(uint8_t*)&complete.bdaddr.b[5] = 0x10;
	complete.link_type = ACL_LINK;
	complete.encr_mode = 0;
	hci_send_event_packet(vhci_fd, HCI_EV_CONN_COMPLETE, &complete, sizeof(complete));
	struct hci_ev_remote_features features;
	memset(&features, 0, sizeof(features));
	features.status = 0;
	features.handle = HCI_HANDLE_1;
	hci_send_event_packet(vhci_fd, HCI_EV_REMOTE_FEATURES, &features, sizeof(features));
	struct {
		struct hci_ev_le_meta le_meta;
		struct hci_ev_le_conn_complete le_conn;
	} le_conn;
	memset(&le_conn, 0, sizeof(le_conn));
	le_conn.le_meta.subevent = HCI_EV_LE_CONN_COMPLETE;
	memset(&le_conn.le_conn.bdaddr, 0xaa, 6);
	*(uint8_t*)&le_conn.le_conn.bdaddr.b[5] = 0x11;
	le_conn.le_conn.role = 1;
	le_conn.le_conn.handle = HCI_HANDLE_2;
	hci_send_event_packet(vhci_fd, HCI_EV_LE_META, &le_conn, sizeof(le_conn));
	pthread_join(th, NULL);
	close(hci_sock);
}

static void setup_gadgetfs();
static void setup_binderfs();
static void setup_fusectl();
static void sandbox_common_mount_tmpfs(void)
{
	write_file("/proc/sys/fs/mount-max", "100000");
	if (mkdir("./syz-tmp", 0777))
	exit(1);
	if (mount("", "./syz-tmp", "tmpfs", 0, NULL))
	exit(1);
	if (mkdir("./syz-tmp/newroot", 0777))
	exit(1);
	if (mkdir("./syz-tmp/newroot/dev", 0700))
	exit(1);
	unsigned bind_mount_flags = MS_BIND | MS_REC | MS_PRIVATE;
	if (mount("/dev", "./syz-tmp/newroot/dev", NULL, bind_mount_flags, NULL))
	exit(1);
	if (mkdir("./syz-tmp/newroot/proc", 0700))
	exit(1);
	if (mount("syz-proc", "./syz-tmp/newroot/proc", "proc", 0, NULL))
	exit(1);
	if (mkdir("./syz-tmp/newroot/selinux", 0700))
	exit(1);
	const char* selinux_path = "./syz-tmp/newroot/selinux";
	if (mount("/selinux", selinux_path, NULL, bind_mount_flags, NULL)) {
		if (errno != ENOENT)
	exit(1);
		if (mount("/sys/fs/selinux", selinux_path, NULL, bind_mount_flags, NULL) && errno != ENOENT)
	exit(1);
	}
	if (mkdir("./syz-tmp/newroot/sys", 0700))
	exit(1);
	if (mount("/sys", "./syz-tmp/newroot/sys", 0, bind_mount_flags, NULL))
	exit(1);
	if (mount("/sys/kernel/debug", "./syz-tmp/newroot/sys/kernel/debug", NULL, bind_mount_flags, NULL) && errno != ENOENT)
	exit(1);
	if (mount("/sys/fs/smackfs", "./syz-tmp/newroot/sys/fs/smackfs", NULL, bind_mount_flags, NULL) && errno != ENOENT)
	exit(1);
	if (mount("/proc/sys/fs/binfmt_misc", "./syz-tmp/newroot/proc/sys/fs/binfmt_misc", NULL, bind_mount_flags, NULL) && errno != ENOENT)
	exit(1);
	if (mkdir("./syz-tmp/pivot", 0777))
	exit(1);
	if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) {
		if (chdir("./syz-tmp"))
	exit(1);
	} else {
		if (chdir("/"))
	exit(1);
		if (umount2("./pivot", MNT_DETACH))
	exit(1);
	}
	if (chroot("./newroot"))
	exit(1);
	if (chdir("/"))
	exit(1);
	setup_gadgetfs();
	setup_binderfs();
	setup_fusectl();
}

static void setup_gadgetfs()
{
	if (mkdir("/dev/gadgetfs", 0777)) {
	}
	if (mount("gadgetfs", "/dev/gadgetfs", "gadgetfs", 0, NULL)) {
	}
}

static void setup_fusectl()
{
	if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) {
	}
}

static void setup_binderfs()
{
	if (mkdir("/dev/binderfs", 0777)) {
	}
	if (mount("binder", "/dev/binderfs", "binder", 0, NULL)) {
	}
	if (symlink("/dev/binderfs", "./binderfs")) {
	}
}

static void loop();

static void sandbox_common()
{
	prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
	if (getppid() == 1)
	exit(1);
	struct rlimit rlim;
	rlim.rlim_cur = rlim.rlim_max = (200 << 20);
	setrlimit(RLIMIT_AS, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 32 << 20;
	setrlimit(RLIMIT_MEMLOCK, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 136 << 20;
	setrlimit(RLIMIT_FSIZE, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 1 << 20;
	setrlimit(RLIMIT_STACK, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 128 << 20;
	setrlimit(RLIMIT_CORE, &rlim);
	rlim.rlim_cur = rlim.rlim_max = 256;
	setrlimit(RLIMIT_NOFILE, &rlim);
	if (unshare(CLONE_NEWNS)) {
	}
	if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) {
	}
	if (unshare(CLONE_NEWIPC)) {
	}
	if (unshare(0x02000000)) {
	}
	if (unshare(CLONE_NEWUTS)) {
	}
	if (unshare(CLONE_SYSVSEM)) {
	}
	typedef struct {
		const char* name;
		const char* value;
	} sysctl_t;
	static const sysctl_t sysctls[] = {
	    {"/proc/sys/kernel/shmmax", "16777216"},
	    {"/proc/sys/kernel/shmall", "536870912"},
	    {"/proc/sys/kernel/shmmni", "1024"},
	    {"/proc/sys/kernel/msgmax", "8192"},
	    {"/proc/sys/kernel/msgmni", "1024"},
	    {"/proc/sys/kernel/msgmnb", "1024"},
	    {"/proc/sys/kernel/sem", "1024 1048576 500 1024"},
	};
	unsigned i;
	for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++)
		write_file(sysctls[i].name, sysctls[i].value);
}

static int wait_for_loop(int pid)
{
	if (pid < 0)
	exit(1);
	int status = 0;
	while (waitpid(-1, &status, __WALL) != pid) {
	}
	return WEXITSTATUS(status);
}

static void drop_caps(void)
{
	struct __user_cap_header_struct cap_hdr = {};
	struct __user_cap_data_struct cap_data[2] = {};
	cap_hdr.version = _LINUX_CAPABILITY_VERSION_3;
	cap_hdr.pid = getpid();
	if (syscall(SYS_capget, &cap_hdr, &cap_data))
	exit(1);
	const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE);
	cap_data[0].effective &= ~drop;
	cap_data[0].permitted &= ~drop;
	cap_data[0].inheritable &= ~drop;
	if (syscall(SYS_capset, &cap_hdr, &cap_data))
	exit(1);
}

static int do_sandbox_none(void)
{
	if (unshare(CLONE_NEWPID)) {
	}
	int pid = fork();
	if (pid != 0)
		return wait_for_loop(pid);
	initialize_vhci();
	sandbox_common();
	drop_caps();
	if (unshare(CLONE_NEWNET)) {
	}
	write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535");
	sandbox_common_mount_tmpfs();
	loop();
	exit(1);
}

void loop(void)
{
		if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {}

}
int main(void)
{
		syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
	syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
	syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
	const char* reason;
	(void)reason;
			do_sandbox_none();
	return 0;
}