Medium · published January 11, 2025
In the Linux kernel, the following vulnerability has been resolved:
i3c: Use i3cdev->desc->info instead of calling i3c_device_get_info() to avoid deadlock
A deadlock may happen since the i3c_master_register() acquires
&i3cbus->lock twice. See the log below.
Use i3cdev->desc->info instead of calling i3c_device_info() to
avoid acquiring the lock twice.
v2:
- Modified the title and commit message
============================================
WARNING: possible recursive locking detected
6.11.0-mainline
--------------------------------------------
init/1 is trying to acquire lock:
f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_bus_normaluse_lock
but task is already holding lock:
f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&i3cbus->lock);
lock(&i3cbus->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by init/1:
#0: fcffff809b6798f8 (&dev->mutex){....}-{3:3}, at: __driver_attach
#1: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register
stack backtrace:
CPU: 6 UID: 0 PID: 1 Comm: init
Call trace:
dump_backtrace+0xfc/0x17c
show_stack+0x18/0x28
dump_stack_lvl+0x40/0xc0
dump_stack+0x18/0x24
print_deadlock_bug+0x388/0x390
__lock_acquire+0x18bc/0x32ec
lock_acquire+0x134/0x2b0
down_read+0x50/0x19c
i3c_bus_normaluse_lock+0x14/0x24
i3c_device_get_info+0x24/0x58
i3c_device_uevent+0x34/0xa4
dev_uevent+0x310/0x384
kobject_uevent_env+0x244/0x414
kobject_uevent+0x14/0x20
device_add+0x278/0x460
device_register+0x20/0x34
i3c_master_register_new_i3c_devs+0x78/0x154
i3c_master_register+0x6a0/0x6d4
mtk_i3c_master_probe+0x3b8/0x4d8
platform_probe+0xa0/0xe0
really_probe+0x114/0x454
__driver_probe_device+0xa0/0x15c
driver_probe_device+0x3c/0x1ac
__driver_attach+0xc4/0x1f0
bus_for_each_dev+0x104/0x160
driver_attach+0x24/0x34
bus_add_driver+0x14c/0x294
driver_register+0x68/0x104
__platform_driver_register+0x20/0x30
init_module+0x20/0xfe4
do_one_initcall+0x184/0x464
do_init_module+0x58/0x1ec
load_module+0xefc/0x10c8
__arm64_sys_finit_module+0x238/0x33c
invoke_syscall+0x58/0x10c
el0_svc_common+0xa8/0xdc
do_el0_svc+0x1c/0x28
el0_svc+0x50/0xac
el0t_64_sync_handler+0x70/0xbc
el0t_64_sync+0x1a8/0x1ac