linux-stable/drivers/i3c
Frank Li 3b2ac810d8 i3c: master: svc: fix possible assignment of the same address to two devices
svc_i3c_master_do_daa() {
    ...
    for (i = 0; i < dev_nb; i++) {
        ret = i3c_master_add_i3c_dev_locked(m, addrs[i]);
        if (ret)
            goto rpm_out;
    }
}

If two devices (A and B) are detected in DAA and address 0xa is assigned to
device A and 0xb to device B, a failure in i3c_master_add_i3c_dev_locked()
for device A (addr: 0xa) could prevent device B (addr: 0xb) from being
registered on the bus. The I3C stack might still consider 0xb a free
address. If a subsequent Hotjoin occurs, 0xb might be assigned to Device A,
causing both devices A and B to use the same address 0xb, violating the I3C
specification.

The return value for i3c_master_add_i3c_dev_locked() should not be checked
because subsequent steps will scan the entire I3C bus, independent of
whether i3c_master_add_i3c_dev_locked() returns success.

If device A registration fails, there is still a chance to register device
B. i3c_master_add_i3c_dev_locked() can reset DAA if a failure occurs while
retrieving device information.

Cc: stable@kernel.org
Fixes: 317bacf960 ("i3c: master: add enable(disable) hot join in sys entry")
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20241002-svc-i3c-hj-v6-6-7e6e1d3569ae@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-31 23:53:39 +01:00
..
master i3c: master: svc: fix possible assignment of the same address to two devices 2024-10-31 23:53:39 +01:00
device.c i3c: Add comment for -EAGAIN in i3c_device_do_priv_xfers() 2024-05-23 00:29:19 +02:00
internals.h i3c: master: Enhance i3c_bus_type visibility for device searching & event monitoring 2024-07-26 14:21:30 +02:00
Kconfig i3c: Add core I3C infrastructure 2018-11-12 10:33:49 +01:00
Makefile i3c: Add core I3C infrastructure 2018-11-12 10:33:49 +01:00
master.c i3c: master: Fix dynamic address leak when 'assigned-address' is present 2024-10-31 23:51:00 +01:00