Bug 2348246 (CVE-2022-49299)

Summary: CVE-2022-49299 kernel: usb: dwc2: gadget: don't reset gadget's driver->bus
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-26 03:22:43 UTC
In the Linux kernel, the following vulnerability has been resolved:

usb: dwc2: gadget: don't reset gadget's driver->bus

UDC driver should not touch gadget's driver internals, especially it
should not reset driver->bus. This wasn't harmful so far, but since
commit fc274c1e9973 ("USB: gadget: Add a new bus for gadgets") gadget
subsystem got it's own bus and messing with ->bus triggers the
following NULL pointer dereference:

dwc2 12480000.hsotg: bound driver g_ether
8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000000
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in: ...
CPU: 0 PID: 620 Comm: modprobe Not tainted 5.18.0-rc5-next-20220504 #11862
Hardware name: Samsung Exynos (Flattened Device Tree)
PC is at module_add_driver+0x44/0xe8
LR is at sysfs_do_create_link_sd+0x84/0xe0
...
Process modprobe (pid: 620, stack limit = 0x(ptrval))
...
 module_add_driver from bus_add_driver+0xf4/0x1e4
 bus_add_driver from driver_register+0x78/0x10c
 driver_register from usb_gadget_register_driver_owner+0x40/0xb4
 usb_gadget_register_driver_owner from do_one_initcall+0x44/0x1e0
 do_one_initcall from do_init_module+0x44/0x1c8
 do_init_module from load_module+0x19b8/0x1b9c
 load_module from sys_finit_module+0xdc/0xfc
 sys_finit_module from ret_fast_syscall+0x0/0x54
Exception stack(0xf1771fa8 to 0xf1771ff0)
...
dwc2 12480000.hsotg: new device is high-speed
---[ end trace 0000000000000000 ]---

Fix this by removing driver->bus entry reset.

Comment 1 Avinash Hanwate 2025-02-26 19:16:53 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022634-CVE-2022-49299-6304@gregkh/T