From ff23a7fae9f3010f31638d741673fa9aff331eca Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 12 Jun 2026 11:01:03 +0300 Subject: [PATCH] i3c: master: Prevent reuse of dynamic address on device add failure [ Upstream commit b3ba8383da4d0cff15810e32ea785eceb0a80813 ] i3c_master_add_i3c_dev_locked() is called after a device has already been assigned a dynamic address. If the function fails, the address remains marked as free and may be reallocated to another device, leading to address conflicts on the bus. Ensure the address is not marked as free on failure, by updating the address slot state to prevent the address from being re-used. Emit an error message to inform of the failure. Opportunistically remove the !master check because it is impossible. Note, directly resetting the device's dynamic address is no longer an option, since Direct RSTDAA was deprecated from I3C starting from version 1.1 and v1.1 (or later) target devices are meant to NACK it. Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260612080107.11606-4-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin --- drivers/i3c/master.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 5df943d25cf0..add78b03c533 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -1861,12 +1861,11 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master, bool enable_ibi = false; int ret; - if (!master) - return -EINVAL; - newdev = i3c_master_alloc_i3c_dev(master, &info); - if (IS_ERR(newdev)) - return PTR_ERR(newdev); + if (IS_ERR(newdev)) { + ret = PTR_ERR(newdev); + goto err_prevent_addr_reuse; + } ret = i3c_master_attach_i3c_dev(master, newdev); if (ret) @@ -1986,6 +1985,16 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master, err_free_dev: i3c_master_free_i3c_dev(newdev); +err_prevent_addr_reuse: + /* + * Although the device has not been added, the address has been + * assigned. Prevent the address from being used again. + */ + if (i3c_bus_get_addr_slot_status(&master->bus, addr) == I3C_ADDR_SLOT_FREE) + i3c_bus_set_addr_slot_status(&master->bus, addr, I3C_ADDR_SLOT_I3C_DEV); + + dev_err(&master->dev, "Failed to add I3C device at address %u, error %d\n", addr, ret); + return ret; } EXPORT_SYMBOL_GPL(i3c_master_add_i3c_dev_locked);