CVE-2024-26786

2024-04-0409:15:08

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

iommufd

vulnerability

iopt_access_list_id

overwrite

bug

resolved

syzkaller

warn_on

cpu

pid

drivers

io_pagetable

access_change_ioas

access_destroy_object

object_remove

object_destroy_user

access_destroy

test_staccess_release

fput_sync

do_sys_close

sys_close

x64_sys_close

syscall

cve

6.5 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.5%

JSON

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.