<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c, branch v6.18.48</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drm/amdgpu: validate GEM_CREATE domain combinations</title>
<updated>2026-08-23T12:27:01+00:00</updated>
<author>
<name>Candice Li</name>
<email>candice.li@amd.com</email>
</author>
<published>2026-07-27T03:51:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=220aa2589d7321fb68d2e8597862711b5f22ae0b'/>
<id>220aa2589d7321fb68d2e8597862711b5f22ae0b</id>
<content type='text'>
commit 5e9d136ad74df4edec67e502ce267597064d8f86 upstream.

AMDGPU_GEM_CREATE checked domain bits against AMDGPU_GEM_DOMAIN_MASK,
but did not validate domain combinations. Userspace could combine
CPU|GTT|VRAM with DOORBELL, GDS, GWS, or OA, making
amdgpu_bo_placement_from_domain() exceed AMDGPU_BO_MAX_PLACEMENTS and
hit BUG_ON().

Allow combinations only within CPU/GTT/VRAM, and require non-CPU/GTT/
VRAM domains to be specified one at a time. Return -EINVAL for invalid
combinations in amdgpu_gem_create_ioctl().

v2: Rename helper from amdgpu_gem_domain_valid() to
    amdgpu_gem_are_domains_valid() (Christian)

Signed-off-by: Candice Li &lt;candice.li@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit db39852d0c39843cb02048dfb47e4b8c703e9080)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5e9d136ad74df4edec67e502ce267597064d8f86 upstream.

AMDGPU_GEM_CREATE checked domain bits against AMDGPU_GEM_DOMAIN_MASK,
but did not validate domain combinations. Userspace could combine
CPU|GTT|VRAM with DOORBELL, GDS, GWS, or OA, making
amdgpu_bo_placement_from_domain() exceed AMDGPU_BO_MAX_PLACEMENTS and
hit BUG_ON().

Allow combinations only within CPU/GTT/VRAM, and require non-CPU/GTT/
VRAM domains to be specified one at a time. Return -EINVAL for invalid
combinations in amdgpu_gem_create_ioctl().

v2: Rename helper from amdgpu_gem_domain_valid() to
    amdgpu_gem_are_domains_valid() (Christian)

Signed-off-by: Candice Li &lt;candice.li@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit db39852d0c39843cb02048dfb47e4b8c703e9080)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: fix check in amdgpu_hmm_invalidate_gfx</title>
<updated>2026-08-03T09:22:07+00:00</updated>
<author>
<name>Christian König</name>
<email>christian.koenig@amd.com</email>
</author>
<published>2026-06-24T14:00:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=15a7cb71a5748a718453f3b01e1da3b52349c043'/>
<id>15a7cb71a5748a718453f3b01e1da3b52349c043</id>
<content type='text'>
commit 52f650963d8825e97a0ccdd2b616f8a01d9d3d38 upstream.

For a short moment during alloc/free the userptr BO is not part of his VM,
so bo-&gt;vm_bo can be NULL.

Keep a reference to the VM root PD as parent of the userptr BO so that
we can always use that to wait for all submissions of the VM instead of
only the one involving the userptr BO.

Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Fixes: 91250893cbaa ("drm/amdgpu: fix waiting for all submissions for userptrs")
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5399
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit 631849ff5d603841e74f19f4a5e30fe1f7d7cf30)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 52f650963d8825e97a0ccdd2b616f8a01d9d3d38 upstream.

For a short moment during alloc/free the userptr BO is not part of his VM,
so bo-&gt;vm_bo can be NULL.

Keep a reference to the VM root PD as parent of the userptr BO so that
we can always use that to wait for all submissions of the VM instead of
only the one involving the userptr BO.

Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Fixes: 91250893cbaa ("drm/amdgpu: fix waiting for all submissions for userptrs")
Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5399
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit 631849ff5d603841e74f19f4a5e30fe1f7d7cf30)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: check amdgpu_vm_bo_find() result in GET_MAPPING_INFO</title>
<updated>2026-08-03T09:21:49+00:00</updated>
<author>
<name>Mario Limonciello</name>
<email>mario.limonciello@amd.com</email>
</author>
<published>2026-06-13T02:11:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ddba17b3dfa0efc80d6c98621c2fb7af66adb622'/>
<id>ddba17b3dfa0efc80d6c98621c2fb7af66adb622</id>
<content type='text'>
commit 93475c34111916df71c63e510fc52db01351f809 upstream.

The AMDGPU_GEM_OP_GET_MAPPING_INFO path of amdgpu_gem_op_ioctl() looks
up the bo_va for the buffer object in the caller's VM via
amdgpu_vm_bo_find(), but uses the returned pointer without checking it.

amdgpu_vm_bo_find() returns NULL when the BO has no bo_va in that VM,
which is the normal case for a BO that has never been mapped. The result
is fed straight into amdgpu_vm_bo_va_for_each_valid_mapping(), which
expands to list_for_each_entry(mapping, &amp;(bo_va)-&gt;valids, list) and
dereferences bo_va, causing a NULL pointer dereference.

This is reachable by any process able to issue the ioctl (render group)
simply by requesting mapping info for an unmapped BO.

Return -ENOENT when no bo_va is found, jumping to out_exec so the
drm_exec context and GEM object reference are released.

Fixes: 4d82724f7f2b ("drm/amdgpu: Add mapping info option for GEM_OP ioctl")
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit 528b19377affc1cc7362a70a254c1dda793595f9)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 93475c34111916df71c63e510fc52db01351f809 upstream.

The AMDGPU_GEM_OP_GET_MAPPING_INFO path of amdgpu_gem_op_ioctl() looks
up the bo_va for the buffer object in the caller's VM via
amdgpu_vm_bo_find(), but uses the returned pointer without checking it.

amdgpu_vm_bo_find() returns NULL when the BO has no bo_va in that VM,
which is the normal case for a BO that has never been mapped. The result
is fed straight into amdgpu_vm_bo_va_for_each_valid_mapping(), which
expands to list_for_each_entry(mapping, &amp;(bo_va)-&gt;valids, list) and
dereferences bo_va, causing a NULL pointer dereference.

This is reachable by any process able to issue the ioctl (render group)
simply by requesting mapping info for an unmapped BO.

Return -ENOENT when no bo_va is found, jumping to out_exec so the
drm_exec context and GEM object reference are released.

Fixes: 4d82724f7f2b ("drm/amdgpu: Add mapping info option for GEM_OP ioctl")
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit 528b19377affc1cc7362a70a254c1dda793595f9)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: fix integer overflow in amdgpu_gem_align_pitch()</title>
<updated>2026-07-24T14:15:43+00:00</updated>
<author>
<name>Werner Kasselman</name>
<email>werner@verivus.ai</email>
</author>
<published>2026-04-14T05:08:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=daf5d03ddb8ccbe4a9bf22b320de049d2f17a3d1'/>
<id>daf5d03ddb8ccbe4a9bf22b320de049d2f17a3d1</id>
<content type='text'>
[ Upstream commit fc3659f178d4a65599167d5a648bbeef4b0d4446 ]

amdgpu_gem_align_pitch() is passed u32 width and cpp from dumb buffer
creation but uses signed int internally.  The round-up add and the
aligned * cpp multiplication can overflow, returning zero or a negative
pitch.  A zero pitch propagates to a zero-sized GEM object allocation
that reaches userspace via DRM_IOCTL_MODE_CREATE_DUMB.

Switch the helper to unsigned int and use check_add_overflow() /
check_mul_overflow() so wraparound returns zero.  Reject a zero pitch
or size in amdgpu_mode_dumb_create() rather than allocating a zero-
byte BO.

Fixes: 8e911ab770f7 ("drm: amdgpu: Replace drm_fb_get_bpp_depth() with drm_format_plane_cpp()")
Signed-off-by: Werner Kasselman &lt;werner@verivus.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fc3659f178d4a65599167d5a648bbeef4b0d4446 ]

amdgpu_gem_align_pitch() is passed u32 width and cpp from dumb buffer
creation but uses signed int internally.  The round-up add and the
aligned * cpp multiplication can overflow, returning zero or a negative
pitch.  A zero pitch propagates to a zero-sized GEM object allocation
that reaches userspace via DRM_IOCTL_MODE_CREATE_DUMB.

Switch the helper to unsigned int and use check_add_overflow() /
check_mul_overflow() so wraparound returns zero.  Reject a zero pitch
or size in amdgpu_mode_dumb_create() rather than allocating a zero-
byte BO.

Fixes: 8e911ab770f7 ("drm: amdgpu: Replace drm_fb_get_bpp_depth() with drm_format_plane_cpp()")
Signed-off-by: Werner Kasselman &lt;werner@verivus.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: check num_entries in GEM_OP GET_MAPPING_INFO</title>
<updated>2026-06-09T10:28:48+00:00</updated>
<author>
<name>Ziyi Guo</name>
<email>n7l8m4@u.northwestern.edu</email>
</author>
<published>2026-02-08T00:02:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f059b4c493df3e54fe3ffe4658009c31864275da'/>
<id>f059b4c493df3e54fe3ffe4658009c31864275da</id>
<content type='text'>
commit a1ba4594232c87c3b8defd6f89a2e40f8b08395d upstream.

kvcalloc(args-&gt;num_entries, sizeof(*vm_entries), GFP_KERNEL) at
amdgpu_gem.c:1050 uses the user-supplied num_entries directly without
any upper bounds check. Since num_entries is a __u32 and
sizeof(drm_amdgpu_gem_vm_entry) is 32 bytes, a large num_entries
produces an allocation exceeding INT_MAX, triggering
WARNING in __kvmalloc_node_noprof(), causing a kernel WARNING,
TAINT_WARN, and panic on CONFIG_PANIC_ON_WARN=y systems.

Add a size bounds check before we invoke the kvzalloc() to
reject oversized num_entries early with -EINVAL.

Fixes: 4d82724f7f2b ("drm/amdgpu: Add mapping info option for GEM_OP ioctl")
Signed-off-by: Ziyi Guo &lt;n7l8m4@u.northwestern.edu&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit 1fe7bf5457f6efd7be60b17e23163ba54341d73d)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a1ba4594232c87c3b8defd6f89a2e40f8b08395d upstream.

kvcalloc(args-&gt;num_entries, sizeof(*vm_entries), GFP_KERNEL) at
amdgpu_gem.c:1050 uses the user-supplied num_entries directly without
any upper bounds check. Since num_entries is a __u32 and
sizeof(drm_amdgpu_gem_vm_entry) is 32 bytes, a large num_entries
produces an allocation exceeding INT_MAX, triggering
WARNING in __kvmalloc_node_noprof(), causing a kernel WARNING,
TAINT_WARN, and panic on CONFIG_PANIC_ON_WARN=y systems.

Add a size bounds check before we invoke the kvzalloc() to
reject oversized num_entries early with -EINVAL.

Fixes: 4d82724f7f2b ("drm/amdgpu: Add mapping info option for GEM_OP ioctl")
Signed-off-by: Ziyi Guo &lt;n7l8m4@u.northwestern.edu&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit 1fe7bf5457f6efd7be60b17e23163ba54341d73d)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: fix lock leak on ENOMEM in AMDGPU_GEM_OP_GET_MAPPING_INFO</title>
<updated>2026-06-09T10:28:48+00:00</updated>
<author>
<name>Michael Bommarito</name>
<email>michael.bommarito@gmail.com</email>
</author>
<published>2026-05-17T13:17:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1eb86334e391695d4a40743b114afc15df4dc506'/>
<id>1eb86334e391695d4a40743b114afc15df4dc506</id>
<content type='text'>
commit 2e7f55eb408c3f72ee1957a0d0ad11d8648a6379 upstream.

The AMDGPU_GEM_OP_GET_MAPPING_INFO branch of amdgpu_gem_op_ioctl()
holds three cleanup-tracked resources before calling kvcalloc():
the drm_gem_object reference from drm_gem_object_lookup(), the
drm_exec lock on the looked-up GEM via drm_exec_lock_obj(), and
the drm_exec lock on the per-process VM root page directory via
amdgpu_vm_lock_pd().  All three are released by the out_exec
label that every other error path in this function jumps to.
The kvcalloc() failure path returns -ENOMEM directly, skipping
out_exec and leaking all three.

The leaked per-process VM root PD dma_resv lock is the
load-bearing leak: any subsequent operation on the same VM
(further GEM ops, command-submission, eviction, TTM shrinker
callbacks) blocks on the held lock.  DRM_IOCTL_AMDGPU_GEM_OP is
DRM_AUTH | DRM_RENDER_ALLOW, so this is an unprivileged-local
denial of service against the caller's GPU context, reachable
by any process with /dev/dri/renderD* access.

Route the failure through out_exec so drm_exec_fini() and
drm_gem_object_put() run.

Reproduced on stock 7.0.0-10, Ryzen 7 5700U / Radeon Vega
(Lucienne): the failing ioctl returns -ENOMEM and a second
GET_MAPPING_INFO on the same fd then blocks in
drm_exec_lock_obj() on the leaked dma_resv.  SIGKILL on the
caller does not reap the task; the fd-release path during
process exit goes through amdgpu_gem_object_close() -&gt;
drm_exec_prepare_obj() on the same lock, leaving the task in D
state until the box is rebooted.  The patched kernel was not
rebuilt and re-tested on this hardware; the fix is mechanical.
Tested on a single Lucienne / Vega box only.

Ziyi Guo posted an independent INT_MAX-bound check for
args-&gt;num_entries in the same branch [1]; the two patches are
complementary and can land in either order.

Fixes: 4d82724f7f2b ("drm/amdgpu: Add mapping info option for GEM_OP ioctl")
Link: https://lore.kernel.org/all/20260208000255.4073363-1-n7l8m4@u.northwestern.edu/ # [1]
Signed-off-by: Michael Bommarito &lt;michael.bommarito@gmail.com&gt;
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit b69d3256d79de15f54c322986ff4da68f1d65b0a)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2e7f55eb408c3f72ee1957a0d0ad11d8648a6379 upstream.

The AMDGPU_GEM_OP_GET_MAPPING_INFO branch of amdgpu_gem_op_ioctl()
holds three cleanup-tracked resources before calling kvcalloc():
the drm_gem_object reference from drm_gem_object_lookup(), the
drm_exec lock on the looked-up GEM via drm_exec_lock_obj(), and
the drm_exec lock on the per-process VM root page directory via
amdgpu_vm_lock_pd().  All three are released by the out_exec
label that every other error path in this function jumps to.
The kvcalloc() failure path returns -ENOMEM directly, skipping
out_exec and leaking all three.

The leaked per-process VM root PD dma_resv lock is the
load-bearing leak: any subsequent operation on the same VM
(further GEM ops, command-submission, eviction, TTM shrinker
callbacks) blocks on the held lock.  DRM_IOCTL_AMDGPU_GEM_OP is
DRM_AUTH | DRM_RENDER_ALLOW, so this is an unprivileged-local
denial of service against the caller's GPU context, reachable
by any process with /dev/dri/renderD* access.

Route the failure through out_exec so drm_exec_fini() and
drm_gem_object_put() run.

Reproduced on stock 7.0.0-10, Ryzen 7 5700U / Radeon Vega
(Lucienne): the failing ioctl returns -ENOMEM and a second
GET_MAPPING_INFO on the same fd then blocks in
drm_exec_lock_obj() on the leaked dma_resv.  SIGKILL on the
caller does not reap the task; the fd-release path during
process exit goes through amdgpu_gem_object_close() -&gt;
drm_exec_prepare_obj() on the same lock, leaving the task in D
state until the box is rebooted.  The patched kernel was not
rebuilt and re-tested on this hardware; the fix is mechanical.
Tested on a single Lucienne / Vega box only.

Ziyi Guo posted an independent INT_MAX-bound check for
args-&gt;num_entries in the same branch [1]; the two patches are
complementary and can land in either order.

Fixes: 4d82724f7f2b ("drm/amdgpu: Add mapping info option for GEM_OP ioctl")
Link: https://lore.kernel.org/all/20260208000255.4073363-1-n7l8m4@u.northwestern.edu/ # [1]
Signed-off-by: Michael Bommarito &lt;michael.bommarito@gmail.com&gt;
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
(cherry picked from commit b69d3256d79de15f54c322986ff4da68f1d65b0a)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v7</title>
<updated>2026-03-04T12:21:36+00:00</updated>
<author>
<name>Srinivasan Shanmugam</name>
<email>srinivasan.shanmugam@amd.com</email>
</author>
<published>2026-01-09T12:31:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0ac822bf990244874a4f8c1cbbc5857f9f8458be'/>
<id>0ac822bf990244874a4f8c1cbbc5857f9f8458be</id>
<content type='text'>
[ Upstream commit efdc66fe12b07e7b7d28650bd8d4f7e3bb92c5d4 ]

When GPU memory mappings are updated, the driver returns a fence so
userspace knows when the update is finished.

The previous refactor could pick the wrong fence or rely on checks that
are not safe for GPU mappings that stay valid even when memory is
missing. In some cases this could return an invalid fence or cause fence
reference counting problems.

Fix this by (v5,v6, per Christian):
- Starting from the VM’s existing last update fence, so a valid and
  meaningful fence is always returned even when no new work is required.
- Selecting the VM-level fence only for always-valid / PRT mappings using
  the required combined bo_va + bo guard.
- Using the per-BO page table update fence for normal MAP and REPLACE
  operations.
- For UNMAP and CLEAR, returning the fence provided by
  amdgpu_vm_clear_freed(), which may remain unchanged when nothing needs
  clearing.
- Keeping fence reference counting balanced.

v7: Drop the extra bo_va/bo NULL guard since
    amdgpu_vm_is_bo_always_valid() handles NULL BOs correctly (including
    PRT). (Christian)

This makes VM timeline fences correct and prevents crashes caused by
incorrect fence handling.

Fixes: bd8150a1b337 ("drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4")
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Srinivasan Shanmugam &lt;srinivasan.shanmugam@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit efdc66fe12b07e7b7d28650bd8d4f7e3bb92c5d4 ]

When GPU memory mappings are updated, the driver returns a fence so
userspace knows when the update is finished.

The previous refactor could pick the wrong fence or rely on checks that
are not safe for GPU mappings that stay valid even when memory is
missing. In some cases this could return an invalid fence or cause fence
reference counting problems.

Fix this by (v5,v6, per Christian):
- Starting from the VM’s existing last update fence, so a valid and
  meaningful fence is always returned even when no new work is required.
- Selecting the VM-level fence only for always-valid / PRT mappings using
  the required combined bo_va + bo guard.
- Using the per-BO page table update fence for normal MAP and REPLACE
  operations.
- For UNMAP and CLEAR, returning the fence provided by
  amdgpu_vm_clear_freed(), which may remain unchanged when nothing needs
  clearing.
- Keeping fence reference counting balanced.

v7: Drop the extra bo_va/bo NULL guard since
    amdgpu_vm_is_bo_always_valid() handles NULL BOs correctly (including
    PRT). (Christian)

This makes VM timeline fences correct and prevents crashes caused by
incorrect fence handling.

Fixes: bd8150a1b337 ("drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4")
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Srinivasan Shanmugam &lt;srinivasan.shanmugam@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4</title>
<updated>2026-03-04T12:19:53+00:00</updated>
<author>
<name>Srinivasan Shanmugam</name>
<email>srinivasan.shanmugam@amd.com</email>
</author>
<published>2025-12-11T15:55:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e9e477d3197f7d8955a042c0d7f53f78f13218ba'/>
<id>e9e477d3197f7d8955a042c0d7f53f78f13218ba</id>
<content type='text'>
[ Upstream commit bd8150a1b3370a9f7761c5814202a3fe5a79f44f ]

This commit simplifies the amdgpu_gem_va_ioctl function, key updates
include:
 - Moved the logic for managing the last update fence directly into
   amdgpu_gem_va_update_vm.
 - Introduced checks for the timeline point to enable conditional
   replacement or addition of fences.

v2: Addressed review comments from Christian.
v3: Updated comments (Christian).
v4: The previous version selected the fence too early and did not manage its
    reference correctly, which could lead to stale or freed fences being used.
    This resulted in refcount underflows and could crash when updating GPU
    timelines.
    The fence is now chosen only after the VA mapping work is completed, and its
    reference is taken safely. After exporting it to the VM timeline syncobj, the
    driver always drops its local fence reference, ensuring balanced refcounting
    and avoiding use-after-free on dma_fence.

	Crash signature:
	[  205.828135] refcount_t: underflow; use-after-free.
	[  205.832963] WARNING: CPU: 30 PID: 7274 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110
	...
	[  206.074014] Call Trace:
	[  206.076488]  &lt;TASK&gt;
	[  206.078608]  amdgpu_gem_va_ioctl+0x6ea/0x740 [amdgpu]
	[  206.084040]  ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
	[  206.089994]  drm_ioctl_kernel+0x86/0xe0 [drm]
	[  206.094415]  drm_ioctl+0x26e/0x520 [drm]
	[  206.098424]  ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
	[  206.104402]  amdgpu_drm_ioctl+0x4b/0x80 [amdgpu]
	[  206.109387]  __x64_sys_ioctl+0x96/0xe0
	[  206.113156]  do_syscall_64+0x66/0x2d0
	...
	[  206.553351] BUG: unable to handle page fault for address: ffffffffc0dfde90
	...
	[  206.553378] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
	...
	[  206.553405] Call Trace:
	[  206.553409]  &lt;IRQ&gt;
	[  206.553415]  ? __pfx_drm_sched_fence_free_rcu+0x10/0x10 [gpu_sched]
	[  206.553424]  dma_fence_signal+0x30/0x60
	[  206.553427]  drm_sched_job_done.isra.0+0x123/0x150 [gpu_sched]
	[  206.553434]  dma_fence_signal_timestamp_locked+0x6e/0xe0
	[  206.553437]  dma_fence_signal+0x30/0x60
	[  206.553441]  amdgpu_fence_process+0xd8/0x150 [amdgpu]
	[  206.553854]  sdma_v4_0_process_trap_irq+0x97/0xb0 [amdgpu]
	[  206.554353]  edac_mce_amd(E) ee1004(E)
	[  206.554270]  amdgpu_irq_dispatch+0x150/0x230 [amdgpu]
	[  206.554702]  amdgpu_ih_process+0x6a/0x180 [amdgpu]
	[  206.555101]  amdgpu_irq_handler+0x23/0x60 [amdgpu]
	[  206.555500]  __handle_irq_event_percpu+0x4a/0x1c0
	[  206.555506]  handle_irq_event+0x38/0x80
	[  206.555509]  handle_edge_irq+0x92/0x1e0
	[  206.555513]  __common_interrupt+0x3e/0xb0
	[  206.555519]  common_interrupt+0x80/0xa0
	[  206.555525]  &lt;/IRQ&gt;
	[  206.555527]  &lt;TASK&gt;
	...
	[  206.555650] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
	...
	[  206.555667] Kernel panic - not syncing: Fatal exception in interrupt

Link: https://patchwork.freedesktop.org/patch/654669/
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Srinivasan Shanmugam &lt;srinivasan.shanmugam@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bd8150a1b3370a9f7761c5814202a3fe5a79f44f ]

This commit simplifies the amdgpu_gem_va_ioctl function, key updates
include:
 - Moved the logic for managing the last update fence directly into
   amdgpu_gem_va_update_vm.
 - Introduced checks for the timeline point to enable conditional
   replacement or addition of fences.

v2: Addressed review comments from Christian.
v3: Updated comments (Christian).
v4: The previous version selected the fence too early and did not manage its
    reference correctly, which could lead to stale or freed fences being used.
    This resulted in refcount underflows and could crash when updating GPU
    timelines.
    The fence is now chosen only after the VA mapping work is completed, and its
    reference is taken safely. After exporting it to the VM timeline syncobj, the
    driver always drops its local fence reference, ensuring balanced refcounting
    and avoiding use-after-free on dma_fence.

	Crash signature:
	[  205.828135] refcount_t: underflow; use-after-free.
	[  205.832963] WARNING: CPU: 30 PID: 7274 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110
	...
	[  206.074014] Call Trace:
	[  206.076488]  &lt;TASK&gt;
	[  206.078608]  amdgpu_gem_va_ioctl+0x6ea/0x740 [amdgpu]
	[  206.084040]  ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
	[  206.089994]  drm_ioctl_kernel+0x86/0xe0 [drm]
	[  206.094415]  drm_ioctl+0x26e/0x520 [drm]
	[  206.098424]  ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
	[  206.104402]  amdgpu_drm_ioctl+0x4b/0x80 [amdgpu]
	[  206.109387]  __x64_sys_ioctl+0x96/0xe0
	[  206.113156]  do_syscall_64+0x66/0x2d0
	...
	[  206.553351] BUG: unable to handle page fault for address: ffffffffc0dfde90
	...
	[  206.553378] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
	...
	[  206.553405] Call Trace:
	[  206.553409]  &lt;IRQ&gt;
	[  206.553415]  ? __pfx_drm_sched_fence_free_rcu+0x10/0x10 [gpu_sched]
	[  206.553424]  dma_fence_signal+0x30/0x60
	[  206.553427]  drm_sched_job_done.isra.0+0x123/0x150 [gpu_sched]
	[  206.553434]  dma_fence_signal_timestamp_locked+0x6e/0xe0
	[  206.553437]  dma_fence_signal+0x30/0x60
	[  206.553441]  amdgpu_fence_process+0xd8/0x150 [amdgpu]
	[  206.553854]  sdma_v4_0_process_trap_irq+0x97/0xb0 [amdgpu]
	[  206.554353]  edac_mce_amd(E) ee1004(E)
	[  206.554270]  amdgpu_irq_dispatch+0x150/0x230 [amdgpu]
	[  206.554702]  amdgpu_ih_process+0x6a/0x180 [amdgpu]
	[  206.555101]  amdgpu_irq_handler+0x23/0x60 [amdgpu]
	[  206.555500]  __handle_irq_event_percpu+0x4a/0x1c0
	[  206.555506]  handle_irq_event+0x38/0x80
	[  206.555509]  handle_edge_irq+0x92/0x1e0
	[  206.555513]  __common_interrupt+0x3e/0xb0
	[  206.555519]  common_interrupt+0x80/0xa0
	[  206.555525]  &lt;/IRQ&gt;
	[  206.555527]  &lt;TASK&gt;
	...
	[  206.555650] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
	...
	[  206.555667] Kernel panic - not syncing: Fatal exception in interrupt

Link: https://patchwork.freedesktop.org/patch/654669/
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Srinivasan Shanmugam &lt;srinivasan.shanmugam@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: use hmm_pfns instead of array of pages</title>
<updated>2025-09-23T14:22:31+00:00</updated>
<author>
<name>Sunil Khatri</name>
<email>sunil.khatri@amd.com</email>
</author>
<published>2025-09-17T14:42:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c5b3cc417b0260abc74ed32f6baa626c9de917c0'/>
<id>c5b3cc417b0260abc74ed32f6baa626c9de917c0</id>
<content type='text'>
we dont need to allocate local array of pages to hold
the pages returned by the hmm, instead we could use
the hmm_range structure itself to get to hmm_pfn
and get the required pages directly.

This avoids call to alloc/free quite a lot.

Signed-off-by: Sunil Khatri &lt;sunil.khatri@amd.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Acked-by: Felix Kuehling &lt;felix.kuehling@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
we dont need to allocate local array of pages to hold
the pages returned by the hmm, instead we could use
the hmm_range structure itself to get to hmm_pfn
and get the required pages directly.

This avoids call to alloc/free quite a lot.

Signed-off-by: Sunil Khatri &lt;sunil.khatri@amd.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Acked-by: Felix Kuehling &lt;felix.kuehling@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'amd-drm-next-6.18-2025-09-19' of https://gitlab.freedesktop.org/agd5f/linux into drm-next</title>
<updated>2025-09-21T22:45:51+00:00</updated>
<author>
<name>Dave Airlie</name>
<email>airlied@redhat.com</email>
</author>
<published>2025-09-21T22:44:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=342f141ba9f4c9e39de342d047a5245e8f4cda19'/>
<id>342f141ba9f4c9e39de342d047a5245e8f4cda19</id>
<content type='text'>
amd-drm-next-6.18-2025-09-19:

amdgpu:
- Fence drv clean up fix
- DPC fixes
- Misc display fixes
- Support the MMIO remap page as a ttm pool
- JPEG parser updates
- UserQ updates
- VCN ctx handling fixes
- Documentation updates
- Misc cleanups
- SMU 13.0.x updates
- SI DPM updates
- GC 11.x cleaner shader updates
- DMCUB updates
- DML fixes
- Improve fallback handling for pixel encoding
- VCN reset improvements
- DCE6 DC updates
- DSC fixes
- Use devm for i2c buses
- GPUVM locking updates
- GPUVM documentation improvements
- Drop non-DC DCE11 code
- S0ix fixes
- Backlight fix
- SR-IOV fixes

amdkfd:
- SVM updates

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;

From: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Link: https://lore.kernel.org/r/20250919193354.2989255-1-alexander.deucher@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
amd-drm-next-6.18-2025-09-19:

amdgpu:
- Fence drv clean up fix
- DPC fixes
- Misc display fixes
- Support the MMIO remap page as a ttm pool
- JPEG parser updates
- UserQ updates
- VCN ctx handling fixes
- Documentation updates
- Misc cleanups
- SMU 13.0.x updates
- SI DPM updates
- GC 11.x cleaner shader updates
- DMCUB updates
- DML fixes
- Improve fallback handling for pixel encoding
- VCN reset improvements
- DCE6 DC updates
- DSC fixes
- Use devm for i2c buses
- GPUVM locking updates
- GPUVM documentation improvements
- Drop non-DC DCE11 code
- S0ix fixes
- Backlight fix
- SR-IOV fixes

amdkfd:
- SVM updates

Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;

From: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Link: https://lore.kernel.org/r/20250919193354.2989255-1-alexander.deucher@amd.com
</pre>
</div>
</content>
</entry>
</feed>
