CVE-2024-43098

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

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/25.html
• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/27.html

References

• https://git.kernel.org/stable/c/1f51ae217d09c361ede900b94735a6d2df6c0344
• https://git.kernel.org/stable/c/2d98fa2a50b8058de52ada168fa5dbabb574711b
• https://git.kernel.org/stable/c/5ac1dd51aaa0ce8b5421d1137e857955a4b6f55e
• https://git.kernel.org/stable/c/6cf7b65f7029914dc0cd7db86fac9ee5159008c6
• https://git.kernel.org/stable/c/816187b1833908941286e71b0041059a4acd52ed
• https://git.kernel.org/stable/c/9a2173660ee53d5699744f02e6ab7bf89fcd0b1a
• https://git.kernel.org/stable/c/ffe19e363c6f8b992ba835a361542568dea17409