CVE-2024-26785

iommufd: Fix protection fault in iommufd_test_syz_conv_iova

MEDIUM
5.5
CVSS Score
Published: April 4, 2024 at 08:20 AM UTC
Updated: June 17, 2026 at 07:18 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: iommufd: Fix protection fault in iommufd_test_syz_conv_iova Syzkaller reported the following bug: general protection fault, probably for non-canonical address 0xdffffc0000000038: 0000 [#1] SMP KASAN KASAN: null-ptr-deref in range [0x00000000000001c0-0x00000000000001c7] Call Trace: lock_acquire lock_acquire+0x1ce/0x4f0 down_read+0x93/0x4a0 iommufd_test_syz_conv_iova+0x56/0x1f0 iommufd_test_access_rw.isra.0+0x2ec/0x390 iommufd_test+0x1058/0x1e30 iommufd_fops_ioctl+0x381/0x510 vfs_ioctl __do_sys_ioctl __se_sys_ioctl __x64_sys_ioctl+0x170/0x1e0 do_syscall_x64 do_syscall_64+0x71/0x140 This is because the new iommufd_access_change_ioas() sets access->ioas to NULL during its process, so the lock might be gone in a concurrent racing context. Fix this by doing the same access->ioas sanity as iommufd_access_rw() and iommufd_access_pin_pages() functions do.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.6 ≤ v < 6.6.556.6 ≤ v < 6.7.96.6 ≤ v < 6.86.8 rc16.8 rc26.8 rc36.8 rc46.8 rc56.8 rc69227da7816dd1a42e20d41e2244cb63c205477ca
Vendor states this is fixed in cf7c2789822db8b5efa34f5ebcf1621bc0008d48 (fixed)
Vendor states this is fixed in fc719ecbca45c9c046640d72baddba3d83e0bc0b (fixed)
Vendor states this is fixed in fd4d5cd7a2e8f08357c9bfc0905957cffe8ce568 (fixed)
Vendor states this is fixed in 6.6 (unaffected)
Vendor states this is fixed in 6.6.55 (unaffected)
Vendor states this is fixed in 6.7.9 (unaffected)
Vendor states this is fixed in 6.8 (unaffected)

References (3)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/cf7c2789822db8b5efa34f5ebcf1621bc0008d48
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/fc719ecbca45c9c046640d72baddba3d83e0bc0b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/fd4d5cd7a2e8f08357c9bfc0905957cffe8ce568

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.5MEDIUMCISA-ADP
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-120

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