Description

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

iommufd: Fix iopt_access_list_id overwrite bug

Syzkaller reported the following WARN_ON:
WARNING: CPU: 1 PID: 4738 at drivers/iommu/iommufd/io_pagetable.c:1360

Call Trace:
iommufd_access_change_ioas+0x2fe/0x4e0
iommufd_access_destroy_object+0x50/0xb0
iommufd_object_remove+0x2a3/0x490
iommufd_object_destroy_user
iommufd_access_destroy+0x71/0xb0
iommufd_test_staccess_release+0x89/0xd0
__fput+0x272/0xb50
__fput_sync+0x4b/0x60
__do_sys_close
__se_sys_close
__x64_sys_close+0x8b/0x110
do_syscall_x64

The mismatch between the access pointer in the list and the passed-in
pointer is resulting from an overwrite of access->iopt_access_list_id, in
iopt_add_access(). Called from iommufd_access_change_ioas() when
xa_alloc() succeeds but iopt_calculate_iova_alignment() fails.

Add a new_id in iopt_add_access() and only update iopt_access_list_id when
returning successfully.

Classification

CVE ID: CVE-2024-26786

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 17.83% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/f1fb745ee0a6fe43f1d84ec369c7e6af2310fda9
https://git.kernel.org/stable/c/9526a46cc0c378d381560279bea9aa34c84298a0
https://git.kernel.org/stable/c/aeb004c0cd6958e910123a1607634401009c9539

Timeline