In the Linux kernel, the following vulnerability has been resolved:

remoteproc: core: Fix ida_free call while not allocated

In the rproc_alloc() function, on error, put_device(&rproc->dev) is
called, leading to the call of the rproc_type_release() function.
An error can occurs before ida_alloc is called.

In such case in rproc_type_release(), the condition (rproc->index >= 0) is
true as rproc->index has been  initialized to 0.
ida_free() is called reporting a warning:
[    4.181906] WARNING: CPU: 1 PID: 24 at lib/idr.c:525 ida_free+0x100/0x164
[    4.186378] stm32-display-dsi 5a000000.dsi: Fixed dependency cycle(s) with /soc/dsi@5a000000/panel@0
[    4.188854] ida_free called for id=0 which is not allocated.
[    4.198256] mipi-dsi 5a000000.dsi.0: Fixed dependency cycle(s) with /soc/dsi@5a000000
[    4.203556] Modules linked in: panel_orisetech_otm8009a dw_mipi_dsi_stm(+) gpu_sched dw_mipi_dsi stm32_rproc stm32_crc32 stm32_ipcc(+) optee(+)
[    4.224307] CPU: 1 UID: 0 PID: 24 Comm: kworker/u10:0 Not tainted 6.12.0 #442
[    4.231481] Hardware name: STM32 (Device Tree Support)
[    4.236627] Workqueue: events_unbound deferred_probe_work_func
[    4.242504] Call trace:
[    4.242522]  unwind_backtrace from show_stack+0x10/0x14
[    4.250218]  show_stack from dump_stack_lvl+0x50/0x64
[    4.255274]  dump_stack_lvl from __warn+0x80/0x12c
[    4.260134]  __warn from warn_slowpath_fmt+0x114/0x188
[    4.265199]  warn_slowpath_fmt from ida_free+0x100/0x164
[    4.270565]  ida_free from rproc_type_release+0x38/0x60
[    4.275832]  rproc_type_release from device_release+0x30/0xa0
[    4.281601]  device_release from kobject_put+0xc4/0x294
[    4.286762]  kobject_put from rproc_alloc.part.0+0x208/0x28c
[    4.292430]  rproc_alloc.part.0 from devm_rproc_alloc+0x80/0xc4
[    4.298393]  devm_rproc_alloc from stm32_rproc_probe+0xd0/0x844 [stm32_rproc]
[    4.305575]  stm32_rproc_probe [stm32_rproc] from platform_probe+0x5c/0xbc

Calling ida_alloc earlier in rproc_alloc ensures that the rproc->index is
properly set.

https://git.kernel.org/stable/c/2cf54928e7e32362215c69b68a6a53d110323bf3

https://git.kernel.org/stable/c/7378aeb664e5ebc396950b36a1f2dedf5aabec20

https://git.kernel.org/stable/c/b32d60a852bb3952886625d0c3b1c9a88c3ceb7c

https://git.kernel.org/stable/c/e9efd9fa4679803fe23188d7b47119cf7bc2de6f

https://git.kernel.org/stable/c/f2013d19b7704cd723ab42664b8d9408ea8cc77c