| 8c07df7c | 11-Aug-2026 |
Peiyang He <peiyang_he@smail.nju.edu.cn> |
iommufd: Fix UAF in selftest IOPF reporting
IOMMUFD selftest TRIGGER_IOPF borrows an attach handle from
group->pasid_array without synchronizing against PASID detach,
then a concurrent iommu_report_
iommufd: Fix UAF in selftest IOPF reporting
IOMMUFD selftest TRIGGER_IOPF borrows an attach handle from
group->pasid_array without synchronizing against PASID detach,
then a concurrent iommu_report_device_fault() can dereference
that borrowed handle's domain pointer after the detach erases
the handle and frees the backing struct iommufd_attach_handle.
TRIGGER_IOPF then dereferences the freed handle, causing a UAF.
Fix by adding a iopf_rwsem in mock_dev to follow the expected design
of a real driver. Hold its read side across the whole
iommu_report_device_fault() call, and its write side around every
path that attaches, detaches, or replaces a device domain.
This can block new reports and drains in-flight reports before an old
attach handle or the IOPF fault parameter can be removed.
Also take the write side while registering a mock device, since
it can invoke the mock driver's default-domain attach callback.
Closes: https://lore.kernel.org/all/D5E3AA41600B2056+f4e15662-bd2b-43ea-91cb-518de429e72c@smail.nju.edu.cn/
Fixes: ddee19971081 ("iommufd/selftest: Add IOPF support for mock device")
Cc: stable@vger.kernel.org
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Assisted-by: Codex:gpt-5.6-terra
Signed-off-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Link: https://patch.msgid.link/38C8DF0A118B7176+20260811095551.2756745-1-peiyang_he@smail.nju.edu.cn
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| d616de49 | 06-Aug-2026 |
Peiyang He <peiyang_he@smail.nju.edu.cn> |
iommu/iommufd: Fix NULL pointer deref in iommufd_ioas_change_process when racing with iopt_map_file_pages
iommufd_ioas_change_process() iterates every IOAS area while only
holding every IOAS iova_rw
iommu/iommufd: Fix NULL pointer deref in iommufd_ioas_change_process when racing with iopt_map_file_pages
iommufd_ioas_change_process() iterates every IOAS area while only
holding every IOAS iova_rwsem, so it assumes every area has a non-NULL
pages pointer. That assumption can be false when it runs concurrently
with iopt_map_file_pages().
iopt_map_pages() executes in two phases. It first creates the area and
inserts it into the interval tree under iova_rwsem, with area->pages
still NULL. It then drops iova_rwsem and later fills area->pages
under domains_rwsem. This leaves a window between area creation and
area->pages fill where a concurrent iommufd_ioas_change_process()
can observe the area and dereference a NULL area->pages pointer,
leading to a NULL pointer dereference:
BUG: kernel NULL pointer dereference, address: 00000000000000c0
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 4b655067 P4D 4b655067 PUD 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 0 UID: 0 PID: 11841 Comm: syz.1.628 Not tainted 7.1.0 #3 PREEMPT(full)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:iommufd_ioas_change_process+0x419/0xd50 drivers/iommu/iommufd/ioas.c:538
Code: 48 89 c3 48 85 c0 0f 84 cc 00 00 00 e8 10 f5 cb fd 48 8d 7b 68 e8 a7 b5 eb fd 48 8b 6b 68 48 8d bd c0 00 00 00 e8 17 b2 eb fd <8b> ad c0 00 00 00 bf 01 00 00 00 89 ee e8 85 ef cb fd 83 fd 01 74
RSP: 0018:ffffc90015c17d28 EFLAGS: 00010246
RAX: ffff8880186d5328 RBX: ffff88801d25e240 RCX: 0000000080000000
RDX: 00000000000002d7 RSI: ffffffff83ba9e10 RDI: 00000000000000c0
RBP: 0000000000000000 R08: ffffffff8e781eb8 R09: 0000000000000000
R10: 00000000000000c0 R11: ffffffff83ba9e29 R12: ffff88802e216008
R13: ffff88802e216000 R14: 0000000000000001 R15: 0000000000000000
FS: 00007f4aea3f66c0(0000) GS:ffff8880b1fa1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000c0 CR3: 000000004b75c000 CR4: 0000000000350ef0
Call Trace:
<TASK>
iommufd_fops_ioctl+0x287/0x400 drivers/iommu/iommufd/main.c:533
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x120/0x170 fs/ioctl.c:583
x64_sys_call+0x1092/0x1fb0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10a/0x680 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4aec1a82bd
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4aea3f6018 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4aec436090 RCX: 00007f4aec1a82bd
RDX: 0000200000000180 RSI: 0000000000003b92 RDI: 0000000000000003
RBP: 00007f4aec250295 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4aec436128 R14: 00007f4aec436090 R15: 00007ffd04ef23e0
</TASK>
Modules linked in:
CR2: 00000000000000c0
---[ end trace 0000000000000000 ]---
RIP: 0010:iommufd_ioas_change_process+0x419/0xd50 drivers/iommu/iommufd/ioas.c:538
Code: 48 89 c3 48 85 c0 0f 84 cc 00 00 00 e8 10 f5 cb fd 48 8d 7b 68 e8 a7 b5 eb fd 48 8b 6b 68 48 8d bd c0 00 00 00 e8 17 b2 eb fd <8b> ad c0 00 00 00 bf 01 00 00 00 89 ee e8 85 ef cb fd 83 fd 01 74
RSP: 0018:ffffc90015c17d28 EFLAGS: 00010246
RAX: ffff8880186d5328 RBX: ffff88801d25e240 RCX: 0000000080000000
RDX: 00000000000002d7 RSI: ffffffff83ba9e10 RDI: 00000000000000c0
RBP: 0000000000000000 R08: ffffffff8e781eb8 R09: 0000000000000000
R10: 00000000000000c0 R11: ffffffff83ba9e29 R12: ffff88802e216008
R13: ffff88802e216000 R14: 0000000000000001 R15: 0000000000000000
FS: 00007f4aea3f66c0(0000) GS:ffff8880b1fa1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000c0 CR3: 000000004b75c000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
0: 48 89 c3 mov %rax,%rbx
3: 48 85 c0 test %rax,%rax
6: 0f 84 cc 00 00 00 je 0xd8
c: e8 10 f5 cb fd call 0xfdcbf521
11: 48 8d 7b 68 lea 0x68(%rbx),%rdi
15: e8 a7 b5 eb fd call 0xfdebb5c1
1a: 48 8b 6b 68 mov 0x68(%rbx),%rbp
1e: 48 8d bd c0 00 00 00 lea 0xc0(%rbp),%rdi
25: e8 17 b2 eb fd call 0xfdebb241
* 2a: 8b ad c0 00 00 00 mov 0xc0(%rbp),%ebp <-- trapping instruction
30: bf 01 00 00 00 mov $0x1,%edi
35: 89 ee mov %ebp,%esi
37: e8 85 ef cb fd call 0xfdcbefc1
3c: 83 fd 01 cmp $0x1,%ebp
3f: 74 .byte 0x74
Fix by mirroring the handling logic in iopt_unmap_iova_range(),
i.e. return -EBUSY if area->pages is NULL.
Fixes: 829ed626499c ("iommufd: Add IOMMU_IOAS_CHANGE_PROCESS")
Link: https://patch.msgid.link/r/7344B7A7B9957A65+20260806045059.1884737-1-peiyang_he@smail.nju.edu.cn
Cc: stable@vger.kernel.org
Signed-off-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 4ac2ce12 | 26-Jul-2026 |
Shuai Xue <xueshuai@linux.alibaba.com> |
iommufd: Release current IOAS on xa_store() failure
iommufd_take_all_iova_rwsem() takes an object reference and the
iova_rwsem write lock before storing the IOAS in the temporary ioas_list
xarray.
iommufd: Release current IOAS on xa_store() failure
iommufd_take_all_iova_rwsem() takes an object reference and the
iova_rwsem write lock before storing the IOAS in the temporary ioas_list
xarray.
If xa_store() fails, the current IOAS has not been inserted into
ioas_list yet. iommufd_release_all_iova_rwsem() only unwinds IOAS
objects already present in that xarray, so it cannot release the current
IOAS.
Release the current IOAS rwsem and object reference before unwinding the
previously stored entries.
Fixes: 051ae5aa73d7 ("iommufd: Lock all IOAS objects")
Cc: stable@vger.kernel.org
Assisted-by: Qoder:Qwen-3.8-MAX-Preview
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
show more ...
|
| 738e6f32 | 20-Jul-2026 |
Peiyang He <peiyang_he@smail.nju.edu.cn> |
iommu/iommufd: Fix IOPF group ownership UAF
iopf_group_alloc() links each last-page IOPF group into the generic IOPF
pending list before invoking the domain fault handler.
iommufd_fault_iopf_handler
iommu/iommufd: Fix IOPF group ownership UAF
iopf_group_alloc() links each last-page IOPF group into the generic IOPF
pending list before invoking the domain fault handler.
iommufd_fault_iopf_handler() also queued an accepted group in the
IOMMUFD deliver list without removing it from the generic pending list.
When detach or HWPT replacement drops the device's IOPF reference count
to zero, an IOMMU driver may call iopf_queue_remove_device(). That
function responds to and frees groups through the generic pending list
without removing the same groups from IOMMUFD's deliver list or response
xarray. A later read, response, or cleanup can then access the freed
group and cause a UAF.
Fix this by dequeuing an accepted group from the generic pending list
before IOMMUFD queues it for userspace response.
Make iopf_group_response() send a response regardless of pending-list
membership, so the dequeued group can still be completed by IOMMUFD.
Link: https://patch.msgid.link/r/3CFD314D0FE4D7EC+20260720085017.3998878-2-peiyang_he@smail.nju.edu.cn
Closes: https://lore.kernel.org/all/B4F28798E2E784CA+d29f723c-b2b5-4b67-8d1c-4f7b9b0b27cb@smail.nju.edu.cn/
Fixes: 34765cbc679c ("iommufd: Associate fault object with iommufd_hw_pgtable")
Cc: stable@vger.kernel.org
Tested-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 60decab3 | 06-Jul-2026 |
Jacob Pan <jacob.pan@linux.microsoft.com> |
iommufd: Add an ioctl to query PA from IOVA for noiommu mode
To support no-IOMMU mode where userspace drivers perform unsafe DMA
using physical addresses, introduce a new API to retrieve the
physica
iommufd: Add an ioctl to query PA from IOVA for noiommu mode
To support no-IOMMU mode where userspace drivers perform unsafe DMA
using physical addresses, introduce a new API to retrieve the
physical address of a user-allocated DMA buffer that has been mapped to
an IOVA via IOMMU_IOAS_MAP. The mapping is backed by SW-only I/O page
tables maintained by the GENERIC_PT framework.
Link: https://patch.msgid.link/r/a60a601509688e8552c75e668deb548c93974a3b.1783360051.git.jacob.pan@linux.microsoft.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Co-developed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Fixes: 2c6cf6ab1564 ("iommufd: Allow binding to a noiommu device")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 072f454c | 06-Jul-2026 |
Jason Gunthorpe <jgg@nvidia.com> |
iommufd: Allow binding to a noiommu device
Allow iommufd to bind devices without an IOMMU (noiommu mode) by creating
a dummy igroup for such devices and skipping hwpt operations.
This enables noiom
iommufd: Allow binding to a noiommu device
Allow iommufd to bind devices without an IOMMU (noiommu mode) by creating
a dummy igroup for such devices and skipping hwpt operations.
This enables noiommu devices to operate through the same iommufd API as IOMMU-
capable devices.
Link: https://patch.msgid.link/r/2c6cf6ab1564426050e637863c9b0d3b25541c63.1783360051.git.jacob.pan@linux.microsoft.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Fixes: 2c6cf6ab1564 ("iommufd: Allow binding to a noiommu device")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| cfa82148 | 06-Jul-2026 |
Jason Gunthorpe <jgg@nvidia.com> |
iommufd: Move igroup allocation to a function
So it can be reused in the next patch which allows binding to noiommu
device.
Link: https://patch.msgid.link/r/6bc8e5eaee89e1dc5f07d13dff69b9670b55923a
iommufd: Move igroup allocation to a function
So it can be reused in the next patch which allows binding to noiommu
device.
Link: https://patch.msgid.link/r/6bc8e5eaee89e1dc5f07d13dff69b9670b55923a.1783360051.git.jacob.pan@linux.microsoft.com
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Fixes: 2c6cf6ab1564 ("iommufd: Allow binding to a noiommu device")
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 17ea9f74 | 06-Jul-2026 |
Jason Gunthorpe <jgg@nvidia.com> |
iommufd: Support a HWPT without an iommu driver for noiommu
Create just a little part of a real iommu driver, enough to
slot in under the dev_iommu_ops() and allow iommufd to call
domain_alloc_pagin
iommufd: Support a HWPT without an iommu driver for noiommu
Create just a little part of a real iommu driver, enough to
slot in under the dev_iommu_ops() and allow iommufd to call
domain_alloc_paging_flags() and fail everything else.
This allows explicitly creating a HWPT under an IOAS.
A new Kconfig option IOMMUFD_NOIOMMU is introduced to differentiate
from the VFIO group/container based noiommu mode.
Link: https://patch.msgid.link/r/8d1ad0b90db0381d4139eda5c126cc8d168d89f8.1783360051.git.jacob.pan@linux.microsoft.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Fixes: 2c6cf6ab1564 ("iommufd: Allow binding to a noiommu device")
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 9be311cf | 06-Jul-2026 |
Nicolin Chen <nicolinc@nvidia.com> |
iommufd/viommu: Publish a vDEVICE only after vdevice_init() succeeds
iommufd_vdevice_alloc_ioctl() adds the vDEVICE to the viommu->vdevs xarray
with xa_cmpxchg() before the driver's vdevice_init() o
iommufd/viommu: Publish a vDEVICE only after vdevice_init() succeeds
iommufd_vdevice_alloc_ioctl() adds the vDEVICE to the viommu->vdevs xarray
with xa_cmpxchg() before the driver's vdevice_init() op runs. That op is
where a driver validates the device and may reject it, but the xarray entry
is already live by then: a concurrent IOMMU_HWPT_INVALIDATE can look it up
with iommufd_viommu_find_dev() and run the driver invalidation path against
a device that vdevice_init() would have refused.
Reserve the index with xa_insert(): it stores a zero entry that reads back
as NULL, and returns -EBUSY on a duplicate virt_id. Run vdevice_init() and
store the vDEVICE pointer only once it succeeds. A failed vdevice_init()
releases the reservation, so lookups observe the vDEVICE only after it is
fully initialized and accepted.
Fixes: ed42eee797ff3 ("iommufd/viommu: Add driver-defined vDEVICE support")
Link: https://patch.msgid.link/r/1e05999347f4bf583edbc6a1312c857d5548708c.1783311134.git.nicolinc@nvidia.com
Cc: stable@vger.kernel.org
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Assisted-by: Claude:claude-opus-4-8
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 339bd115 | 06-Jul-2026 |
Nicolin Chen <nicolinc@nvidia.com> |
iommufd/viommu: Release the igroup lock on the vdevice_size error path
iommufd_vdevice_alloc_ioctl() takes idev->igroup->lock, then validates the
driver's vdevice_size against the core structure siz
iommufd/viommu: Release the igroup lock on the vdevice_size error path
iommufd_vdevice_alloc_ioctl() takes idev->igroup->lock, then validates the
driver's vdevice_size against the core structure size with a WARN_ON_ONCE.
On failure that guard jumps to out_put_idev, below out_unlock_igroup, so it
skips the mutex_unlock(), leaving the igroup lock held and deadlocking the
next vDEVICE operation on that group.
Jump to out_unlock_igroup instead.
Fixes: ed42eee797ff3 ("iommufd/viommu: Add driver-defined vDEVICE support")
Link: https://patch.msgid.link/r/e903f775d491296a525097e2a90b3eb6a47cf2ef.1783311134.git.nicolinc@nvidia.com
Cc: stable@vger.kernel.org
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Assisted-by: Claude:claude-opus-4-8
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 80621480 | 13-Jul-2026 |
Jason Gunthorpe <jgg@nvidia.com> |
iommufd: Simplify iommufd_device_remove_vdev()
Peiyang reports that this function indirectly includes a fault injection
point through iommufd_get_object() that was intended to cover the uAPI use
of
iommufd: Simplify iommufd_device_remove_vdev()
Peiyang reports that this function indirectly includes a fault injection
point through iommufd_get_object() that was intended to cover the uAPI use
of object IDs, not in places like this that cannot fail.
On deeper inspection this can be written using a dedicated helper to
obtain a users refcount relying entirely on the xa locking instead of
going through the whole get/put scheme. The new helper doesn't need the
fault injection point.
Fixes: 850f14f5b919 ("iommufd: Destroy vdevice on idevice destroy")
Link: https://patch.msgid.link/r/0-v1-719003d53a5b+38b-iommufd_fault_inj_vdev_jgg@nvidia.com
Reported-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Closes: https://lore.kernel.org/r/870BB9ADBBEDDD1A+37c5bfab-ad32-4fc5-a302-57c81a8432b5@smail.nju.edu.cn
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 29f39658 | 14-Jul-2026 |
xiongweimin <xiongweimin@kylinos.cn> |
iommufd: Fix grammar and spelling in comments
Correct detach kdoc ("device/pasid from"), article use before
IOMMUFD_OBJ_*, and "propogated" -> "propagated".
Link: https://patch.msgid.link/r/2026071
iommufd: Fix grammar and spelling in comments
Correct detach kdoc ("device/pasid from"), article use before
IOMMUFD_OBJ_*, and "propogated" -> "propagated".
Link: https://patch.msgid.link/r/20260714024440.188358-1-15927021679@163.com
Signed-off-by: xiongweimin <xiongweimin@kylinos.cn>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| 5f3fc0ad | 09-Jul-2026 |
Peiyang He <peiyang_he@smail.nju.edu.cn> |
iommufd: Reject DMABUF pages from the access pin path
DMABUF pages are not supported for iommufd access pinning.
iommufd_access_pin_pages() returns struct page pointers for
in-kernel CPU access, but
iommufd: Reject DMABUF pages from the access pin path
DMABUF pages are not supported for iommufd access pinning.
iommufd_access_pin_pages() returns struct page pointers for
in-kernel CPU access, but DMABUF-backed iopt_pages do not carry
a userspace address that can be passed to the GUP path.
iopt_pages_rw_access() already rejects IOPT_ADDRESS_DMABUF before doing
CPU access. Apply the same rejection to iopt_area_add_access() before it
takes pages->mutex and calls iopt_pages_fill_xarray().
Otherwise a DMABUF-backed iopt_pages can reach the hole-fill path, where
pfn_reader_user_pin() interprets the union as uptr and
calls pin_user_pages_fast()/pin_user_pages_remote().
This fix also avoids the lockdep warning reported from that path, where
pages_dmabuf_mutex_key is held while gup_fast_fallback() may acquire
mmap_lock.
Link: https://patch.msgid.link/r/CD68F549BF3761B7+20260709050800.520607-1-peiyang_he@smail.nju.edu.cn
Reported-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Closes: https://lore.kernel.org/all/E8540D7D05768C91+8b2ef227-3368-494e-909d-7b28e1489dfb@smail.nju.edu.cn/
Fixes: 71db84a092c3 ("iommufd: Add DMABUF to iopt_pages")
Cc: stable@vger.kernel.org
Tested-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Signed-off-by: Peiyang He <peiyang_he@smail.nju.edu.cn>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
show more ...
|
| dba4254e | 07-Jul-2026 |
yeeli <seven.yi.lee@gmail.com> |
iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get()
When dma_buf_export() succeeds but dma_buf_fd() fails (e.g. -EMFILE from
fd exhaustion), the dmabuf is leaked with no dma_buf_put() cal
iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get()
When dma_buf_export() succeeds but dma_buf_fd() fails (e.g. -EMFILE from
fd exhaustion), the dmabuf is leaked with no dma_buf_put() called.
Reproducer: exhaust fd table near RLIMIT_NOFILE, then repeatedly call
IOMMU_TEST_OP_DMABUF_GET — htop shows unbounded memory growth.
Fix by calling dma_buf_put(dmabuf) on error and returning directly.
Fixes: d2041f1f11dd ("iommufd/selftest: Add some tests for the dmabuf flow")
Link: https://patch.msgid.link/r/20260707030635.221577-1-seven.yi.lee@gmail.com
Signed-off-by: yeeli <seven.yi.lee@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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| 4d709860 | 03-Jun-2026 |
Nicolin Chen <nicolinc@nvidia.com> |
iommufd: Set upper bounds on cache invalidation entry_num and entry_len
iommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len,
each bounded only by U32_MAX. An entry_len beyond t
iommufd: Set upper bounds on cache invalidation entry_num and entry_len
iommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len,
each bounded only by U32_MAX. An entry_len beyond the kernel's struct size
makes the copy helper verify the extra bytes are zero, scanning that excess
in one uninterruptible pass; a multi-gigabyte value over zeroed user memory
trips the soft-lockup watchdog.
A large entry_num is the other half, driving the backend invalidation loop
with no reschedule. The VT-d nested handler, for one, copies each entry and
flushes caches per iteration, pinning the CPU on a non-preemptible kernel.
Cap both in the ioctl. entry_len is held under PAGE_SIZE, above any request
struct, and entry_num under 1 << 19, the order of a hardware invalidation
queue and well beyond any real batch, bounding the per-call loop length.
Fixes: 8c6eabae3807 ("iommufd: Add IOMMU_HWPT_INVALIDATE")
Link: https://patch.msgid.link/r/447fa93663f7526eb361719e83fa8b649464483d.1780521606.git.nicolinc@nvidia.com
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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| f2d70dbd | 09-Jun-2026 |
Jason Gunthorpe <jgg@nvidia.com> |
iommufd: Destroy the pages content after detaching from dmabuf
Sashiko points out this has gotten out of order, the mutex could still be
in use through the dmabuf invalidation callbacks. Don't destr
iommufd: Destroy the pages content after detaching from dmabuf
Sashiko points out this has gotten out of order, the mutex could still be
in use through the dmabuf invalidation callbacks. Don't destroy any of the
pages content until the dmabuf is fully detached.
Fixes: 71db84a092c3 ("iommufd: Add DMABUF to iopt_pages")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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| e745cd2c | 26-May-2026 |
Ankit Soni <Ankit.Soni@amd.com> |
iommufd: Take dma_resv lock before dma_buf_unpin() in release path
dma_buf_unpin() requires the caller to hold the exporter's dma_resv
lock:
void dma_buf_unpin(struct dma_buf_attachment *attach)
iommufd: Take dma_resv lock before dma_buf_unpin() in release path
dma_buf_unpin() requires the caller to hold the exporter's dma_resv
lock:
void dma_buf_unpin(struct dma_buf_attachment *attach)
{
...
dma_resv_assert_held(dmabuf->resv);
...
}
iopt_release_pages() calls dma_buf_unpin() without taking that lock,
so every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases
the last reference on a DMABUF-backed iopt_pages triggers a WARN.
This was hit while running tools/testing/selftests/iommu/iommufd:
WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70
RIP: 0010:dma_buf_unpin+0x62/0x70
Call Trace:
<TASK>
dma_buf_unpin+0x62/0x70
iopt_release_pages+0xe4/0x190
iopt_unmap_iova_range+0x1c7/0x290
iopt_unmap_all+0x1a/0x30
iommufd_ioas_destroy+0x1d/0x50
iommufd_fops_release+0x93/0x150
__fput+0xfc/0x2c0
__x64_sys_close+0x3d/0x80
do_syscall_64+0x65/0x180
</TASK>
Take the dma_resv lock around dma_buf_unpin() in iopt_release_pages(),
matching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the
reservation lock internally, so it must remain outside the locked region.
Fixes: 8c5f9645c389 ("iommufd: Add dma_buf_pin()")
Link: https://patch.msgid.link/r/20260526111034.4079-1-Ankit.Soni@amd.com
Reported-by: Ankit Soni <Ankit.Soni@amd.com>
Signed-off-by: Ankit Soni <Ankit.Soni@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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| 091ab6d7 | 01-Jun-2026 |
Nicolin Chen <nicolinc@nvidia.com> |
iommufd: Avoid partial fault group delivery in iommufd_fault_fops_read()
The cookie returned by xa_alloc() in iommufd_fault_fops_read() is per fault
group, but the inner copy_to_user() runs per faul
iommufd: Avoid partial fault group delivery in iommufd_fault_fops_read()
The cookie returned by xa_alloc() in iommufd_fault_fops_read() is per fault
group, but the inner copy_to_user() runs per fault inside the group. If a
copy fails mid-group, xa_erase clears the cookie and the group is restored
to the deliver list, yet done is not rolled back. The function returns the
partial byte count, with the successfully copied faults sitting at offsets
below done carrying the now-erased cookie. The next read() then re-fetches
the group, allocates a fresh cookie, and re-delivers every fault including
the ones already copied; userspace sees duplicates carrying the new cookie,
and a stale cookie that can never be responded to.
Use a local group_done variable that tracks the per-group progress inside
the inner loop, and only commit done = group_done after the inner loop has
finished successfully. On a copy_to_user failure the outer break skips the
commit, so done remains at its prior start-of-group baseline; the partial
bytes already written past done are undefined to userspace per the read(2)
contract, and the next read re-delivers the whole group atomically.
Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object")
Link: https://patch.msgid.link/r/360cab4d4aeccb0bae275a970e2b3c340a71e0e0.1780343944.git.nicolinc@nvidia.com
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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| 172fc8b1 | 01-Jun-2026 |
Nicolin Chen <nicolinc@nvidia.com> |
iommufd: Break the loop on failure in iommufd_fault_fops_read()
On a copy_to_user() failure inside the inner list_for_each_entry, only the
inner loop breaks; the outer while re-fetches the just-rest
iommufd: Break the loop on failure in iommufd_fault_fops_read()
On a copy_to_user() failure inside the inner list_for_each_entry, only the
inner loop breaks; the outer while re-fetches the just-restored fault group
and retries the failing copy_to_user() forever, spinning the reader at 100%
CPU with fault->mutex held.
Check rc after the inner loop and break the outer while as well.
Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object")
Link: https://patch.msgid.link/r/336a9b6e44fe66a24199d3be777c405c85c98622.1780343944.git.nicolinc@nvidia.com
Cc: stable@vger.kernel.org
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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