The GSP-RM display code in rm/r535/disp.c owns a handful of direct MMIO
routines: the head-timing (vblank) interrupt handler and the per-head
vblank enable/disable. They program display registers, not RM, so they
belong with the rest of the per-chip register code in engine/disp/.
Move them to tu102.c (Turing is the first GSP-capable generation) as
tu102_disp_intr() and tu102_head_vblank_get()/put(), exported for
rm/r535/disp.c, which keeps calling them by name for now. No functional
change.
Fixes: 6cc6e08d45 ("drm/nouveau/kms: add support for GB20x")
Cc: stable@vger.kernel.org
Signed-off-by: Mohamed Ahmed <mohamedahmedegypt2001@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20260825001408.14219-2-mohamedahmedegypt2001@gmail.com
That's right! It looks like this never actually got finished, something
which I just noticed today when I saw this fun message spamming one of my
test machine's kernel logs when enabling display debug output for nouveau:
[drm:drm_crtc_vblank_helper_get_vblank_timestamp_internal] crtc 0 : scanoutpos query failed.
So it looks like we've been falling back to DRM's core fallback for a while
now, whoops.
So, while it seems that we do have the option of doing this through GSP -
that doesn't seem like a great idea. Mainly because reading this from GSP
would involve a lot more latency then we should have for vblank handling
due to the RPC communication. So instead of implementing that, just use
gv100_head_state and gv100_head_rgpos for implementing .state and .rgpos.
It seems to work perfectly fine!
Fixes: 9e99444490 ("drm/nouveau/disp/r535: initial support")
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Timur Tabi <ttabi@nvidia.com>
Cc: Ben Skeggs <bskeggs@nvidia.com>
Cc: James Jones <jajones@nvidia.com>
Cc: Faith Ekstrand <faith.ekstrand@collabora.com>
Cc: Suraj Kandpal <suraj.kandpal@intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Aaron Kling <webgeek1234@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Zhang Enpei <zhang.enpei@zte.com.cn>
Cc: <stable@vger.kernel.org> # v6.7+
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patch.msgid.link/20260429030348.3930866-1-lyude@redhat.com
(cherry picked from commit 804cb093b2)
Signed-off-by: Lyude Paul <lyude@redhat.com>
Bits 15:14 of NPU_SET_{IFM,OFM}_PRECISION select the activation storage
mode on U85 only. On U65 the same field holds the rounding mode, and the
command stream parser has read it as a storage mode since the driver was
added.
That went unnoticed while unknown values fell through the switch, but
now that they are rejected, every U65 command stream that asks for
natural rounding (2) fails CMDSTREAM_BO_CREATE with -EINVAL. Mesa emits
it for average pooling, concatenation, split, unpack, strided slice, LUT
and argmax, which is 72 failures of the Teflon test suite on an i.MX93.
Truncating rounding (1) is misread as well: it picks the two-tile
address path and computes a bogus feature map size from tile bases the
command stream never set.
Read the field as a storage mode only on the hardware where it is one.
Fixes: 5a5e9c0228 ("accel: Add Arm Ethos-U NPU driver")
Fixes: 6b7e006629 ("accel: ethosu: Handle U85 internal chaining buffer")
Assisted-by: Claude:claude-opus-5
Signed-off-by: Tomeu Vizoso <tomeu@tomeuvizoso.net>
Link: https://patch.msgid.link/20260824152612.751007-1-tomeu@tomeuvizoso.net
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
amdxdna_cmd_set_error() looks up the first BO of a command chain, which
takes a reference, and drops it at the end of the function. The mapping of
that BO is established in between, and the failure path returns without the
put, so the reference is leaked.
Ordinary use does not reach it. The chain has been submitted before any of
this runs, so aie2_cmdlist_fill_slot() has already called
amdxdna_cmd_get_op() on that BO and amdxdna_gem_vmap() has cached its
address. What makes it reachable is that the BO is resolved again by
handle here, and the handle is userspace's to recycle: closing it after
submission and importing a dma-buf whose exporter implements no vmap onto
the same id leaves amdxdna_gem_get_obj() returning an object this cannot
map, since prime_import() types every import AMDXDNA_BO_SHARE.
Fixes: d76856beb4 ("accel/amdxdna: Refactor GEM BO handling and add helper APIs for address retrieval")
Signed-off-by: Taimuraz Kaitmazov <taimuraz@kaitmazov.com>
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260819230852.287751-1-taimuraz@kaitmazov.com
A chain whose command_count is zero passes the payload length check,
because struct_size(payload, data, 0) is just the header. The fill loop
then does not run, so offset stays zero and the request is submitted with
a zero-length buffer.
On firmware without AIE2_NPU_COMMAND that ends at the opcode check, since
op is still ERT_INVALID_CMD and aie2_get_chain_msg_op() answers
MSG_OP_MAX_OPCODE. aie2_get_npu_chain_msg_op() answers
MSG_OP_CHAIN_EXEC_NPU whatever it is given, so there the submission
continues to drm_clflush_virt_range(cmd_buf, 0), which reads the byte
before the buffer and faults on the vmap guard page. EXEC_CMD is
reachable by any process that can open the render node.
Reject the request instead.
Fixes: 8ed8b02396 ("accel/amdxdna: Add debug prints for command submission")
Signed-off-by: Taimuraz Kaitmazov <taimuraz@kaitmazov.com>
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260818000019.369366-1-taimuraz@kaitmazov.com
struct amdxdna_cmd_chain contains a flexible array annotated with
__counted_by(command_count). Since the structure is stored in shared
AMDXDNA_BO_SHARE memory, userspace can modify command_count concurrently.
If command_count is changed to zero, the bounds check generated from
__counted_by may fail and trigger a kernel panic.
Remove __counted_by to avoid relying on the userspace-controlled
command_count for the flexible array bounds check.
Fixes: aac243092b ("accel/amdxdna: Add command execution")
Reviewed-by: Max Zhen <max.zhen@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260821033543.1839719-1-lizhi.hou@amd.com
Add a test case that verifies no file descriptor is leaked when
DMA_HEAP_IOCTL_ALLOC succeeds internally but copy_to_user() fails
to deliver the fd number back to userspace.
The failure is triggered by placing the ioctl argument in a private
anonymous page and flipping it to PROT_READ (via mprotect) between
the kernel's copy_from_user() and copy_to_user() calls. With the
buggy kernel the ioctl returns -EFAULT but leaves an extra open fd
in the process's fd table; with the fixed kernel the fd count is
unchanged.
This serves as a regression test for:
"dma-buf: dma-heap: don't publish fd before copy_to_user() succeeds"
Suggested-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Baineng Shou <shoubaineng@gmail.com>
Link: https://lore.kernel.org/r/20260817050457.1005285-5-shoubaineng@gmail.com
Signed-off-by: Christian König <christian.koenig@amd.com>
drm_gem_prime_handle_to_fd() open-codes fd reservation and install
using get_unused_fd_flags() + fd_install() directly. This bypasses
the DMA_BUF_TRACE() call that dma_buf_fd() emits, so observability
tools relying on the trace_dma_buf_fd tracepoint silently miss all
DRM PRIME exports.
Replace the bare fd_install() with dma_buf_fd_install(), which wraps
fd_install() together with DMA_BUF_TRACE(), restoring full tracepoint
coverage. No functional change; the fd lifecycle (get_unused_fd_flags
→ work → install) is already correct.
Note: this patch depends on dma_buf_fd_install() introduced in
"dma-buf: dma-heap: don't publish fd before copy_to_user() succeeds"
[1].
[1] https://lore.kernel.org/dri-devel/20260714114654.3885457-2-shoubaineng@gmail.com/
Suggested-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Baineng Shou <shoubaineng@gmail.com>
Link: https://lore.kernel.org/r/20260817050457.1005285-4-shoubaineng@gmail.com
Signed-off-by: Christian König <christian.koenig@amd.com>
fastrpc_ioctl_alloc_dmabuf() calls dma_buf_fd() which installs the fd
into the caller's fd table before copy_to_user() copies the fd number
back to userspace. If copy_to_user() fails, the fd is already visible
to other threads in the same process but the ioctl returns -EFAULT.
The existing comment in the code even acknowledges the problem:
"The usercopy failed, but we can't do much about it, as dma_buf_fd()
already called fd_install()..."
Now that dma_buf_fd_install() is available (introduced to fix the same
issue in dma-heap), apply the same pattern here: reserve the fd with
get_unused_fd_flags(), attempt copy_to_user(), and only on success call
dma_buf_fd_install() to publish it atomically with the tracepoint. On
copy_to_user() failure, put_unused_fd() and dma_buf_put() cleanly
unwind without any user-visible side effects.
Fixes: 6cffd79504 ("misc: fastrpc: Add support for dmabuf exporter")
Cc: stable@vger.kernel.org
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Baineng Shou <shoubaineng@gmail.com>
Link: https://lore.kernel.org/r/20260817050457.1005285-3-shoubaineng@gmail.com
Signed-off-by: Christian König <christian.koenig@amd.com>
DMA_HEAP_IOCTL_ALLOC allocates a dma-buf and installs an fd into the
caller's fd table via dma_buf_fd() -> fd_install() before
dma_heap_ioctl() copies the result back to userspace. If the trailing
copy_to_user() fails, userspace never learns the fd number, but the
fd (and the underlying dma-buf reference) are already visible to
other threads in the same process and are leaked for the lifetime of
the process.
The obvious "close it on the failure path" fix is unsafe: once
fd_install() has run, another thread can already dup() the fd, send
it via SCM_RIGHTS, or close() it and let its number be reused, so a
subsequent close_fd() from the ioctl path can operate on an unrelated
file. This was pointed out by Christian König on v1 [1].
Restructure the allocation path so that fd_install() is the last,
unfailable step of a successful ioctl:
1. heap->ops->allocate() creates the dma_buf.
2. get_unused_fd_flags() reserves an fd number in the caller's
fd table without publishing it, so
no other thread can observe it.
3. copy_to_user() delivers the fd number to userspace;
on failure the fd is returned with
put_unused_fd() and the dma_buf
reference is dropped with
dma_buf_put(), leaving no user-
visible state behind.
4. dma_buf_fd_install() publishes the fd and emits the
trace_dma_buf_fd tracepoint -- from
here on the ioctl cannot fail.
A new dma_buf_fd_install() helper is introduced in dma-buf.c to wrap
fd_install() together with the DMA_BUF_TRACE() call, preserving the
export tracing that dma_buf_fd() provides. dma_heap_ioctl_allocate()
is refactored to return the struct dma_buf * directly (returning
ERR_PTR on failure) so the caller holds the dmabuf reference across
steps 3 and 4.
The failure at step 3 is easily reachable from userspace: pass a
struct dma_heap_allocation_data that lives in a page whose protection
is flipped to PROT_READ between copy_from_user() and copy_to_user()
(e.g. via mprotect()). Before this change each such ioctl leaks one
dmabuf fd; after it, the fd table is unchanged on failure and only
/dev/dma_heap/<name> remains open.
No UAPI or heap-driver interface change.
[1] https://lore.kernel.org/dri-devel/175e98de-f414-47d7-81c1-c0fe0a8f7f62@amd.com/
Fixes: c02a81fba7 ("dma-buf: Add dma-buf heaps framework")
Cc: stable@vger.kernel.org
Reviewed-by: T.J. Mercier <tjmercier@google.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Baineng Shou <shoubaineng@gmail.com>
Link: https://lore.kernel.org/r/20260817050457.1005285-2-shoubaineng@gmail.com
Signed-off-by: Christian König <christian.koenig@amd.com>
The GUD protocol returns TV mode names as fixed-size
GUD_CONNECTOR_TV_MODE_NAME_LEN entries and requires each name to be
NUL-terminated.
gud_connector_add_tv_mode() currently passes each fixed-size entry
directly to drm_mode_create_tv_properties_legacy(), which eventually
reaches drm_property_add_enum() and strlen(). If a device returns an
entry without a terminating NUL byte, strlen() reads past the end of
the slot and can run beyond the allocated buffer, triggering an
out-of-bounds read.
Validate that each returned TV mode name contains a NUL terminator
within its fixed-size slot before passing it to the DRM property code.
If a malformed entry is found, reject the device response with -EIO.
This fixes the out-of-bounds read without changing the handling of
valid devices, and avoids silently truncating malformed protocol data.
Reported-by: syzbot+9ae8e7884e451eaed5b4@syzkaller.appspotmail.com
Fixes: 40e1a70b4a ("drm: Add GUD USB Display driver")
Signed-off-by: Tao Yu <tao1.yu@intel.com>
Reviewed-by: Ruben Wauters <rubenru09@aol.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ruben Wauters <rubenru09@aol.com>
Link: https://patch.msgid.link/20260819072835.4074130-1-tao1.yu@intel.com
nouveau_channel_del() tears the fence context down first and only drops
the channel-kill subscription later, in the middle of the nvif object
teardown:
if (chan->fence)
nouveau_fence(chan->cli->drm)->context_del(chan);
...
nvif_object_dtor(&chan->vram);
nvif_event_dtor(&chan->kill);
The subscribed handler is nouveau_channel_killed(), which calls
nouveau_channel_kill() and from there nouveau_fence_context_kill() on
chan->fence. A kill event delivered in that window takes fctx->lock and
walks fctx->pending on a fence context that context_del() has already
freed.
Nothing reaches this below Fermi today, because the subscription is
gated on FERMI_CHANNEL_GPFIFO and nothing kills a channel there. On
Fermi and newer the window is real but narrow, since a kill has to land
exactly while the channel is being destroyed. That is reason enough on
its own, which is why this carries a Fixes: tag. The last patch in this
series subscribes Tesla channels as well; nothing kills those today, so
it does not widen the exposure now, but it is the groundwork for a
recovery path that would, and the ordering is better fixed before that
lands than alongside it.
Drop the subscription before anything it depends on is torn down.
Fixes: ea13e5abf8 ("drm/nouveau: signal pending fences when channel has been killed")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: Marek Czernohous <marek@czernohous.de>
Fixes: ea13e5abf8 ("drm/nouveau: signal pending fences when channel has been killed")
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20260812231330.705425-2-mczernohous@gmail.com
SYNC_BO does not constrain its size, so a request for zero bytes reaches
drm_clflush_virt_range(), which ends with an unconditional
clflushopt(end - 1). For an empty range that is the byte before the
mapping, and abo->mem.kva comes from vmap(), so the access lands in the
guard page below the vmalloc area and faults:
BUG: unable to handle page fault for address: ffffd16fbbc70fff
#PF: supervisor read access in kernel mode
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 7 UID: 1000 Comm: sync_bo_probe
RIP: 0010:drm_clflush_virt_range+0x3c/0x70
Call Trace:
amdxdna_drm_sync_bo_ioctl+0x124/0x430 [amdxdna]
drm_ioctl+0x301/0x4c0
__x64_sys_ioctl+0x115/0x2f0
do_syscall_64+0xa6/0x3d0
Any process that can open the render node can do this. Reproduced 3 of 3
times on a Strix Point NPU (1022:17f0), by calling SYNC_BO with size 0 on
an AMDXDNA_BO_SHARE object. The import arm takes the same request but
flushes the whole scatterlist, so it survives it.
Nothing needs flushing for an empty range, so answer before choosing a
path.
Fixes: e252e3f348 ("accel/amdxdna: Revise device bo creation and free")
Cc: stable@vger.kernel.org
Signed-off-by: Taimuraz Kaitmazov <taimuraz@kaitmazov.com>
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260817230655.356785-1-taimuraz@kaitmazov.com
Although 'commit 2feec5ae5d ("accel/qaic: Handle DBC deactivation if the
owner went away")' fixes the scenario it was intended for by walking the
message and only decoding QAIC_TRANS_DEACTIVATE_FROM_DEV, if present, it
skipped over the bounds checking code that is included in decode_message().
This could lead to issues such as reading past the slab allocation's end,
infinite loops or kernel panics. For those issues to happen, a malformed
wire message is needed to be sent from the device.
Instead of duplicating the bounds checking code already present in
decode_message(), use the function inside resp_worker().
Reported-by: Ruikai Peng <ruikai@pwno.io>
Fixes: 2feec5ae5d ("accel/qaic: Handle DBC deactivation if the owner went away")
Reviewed-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com>
Signed-off-by: Youssef Samir <youssef.abdulrahman@oss.qualcomm.com>
Signed-off-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Link: https://patch.msgid.link/20260731152344.1905882-1-youssef.abdulrahman@oss.qualcomm.com
On a Xen PV domain page addresses bear no relation to the real machine
addresses the host would have to use to reach it.
virtio_ring.c handles this correctly, vring_use_map_api() returns true
for any xen_domain() regardless of VIRTIO_F_ACCESS_PLATFORM.
virtio-gpu makes the same decision independently, but its copy
looks only at the feature bit:
bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
QEMU does not set iommu_platform on virtio-vga by default, so
VIRTIO_F_ACCESS_PLATFORM is not negotiated, use_dma_api is false, and
virtio_gpu_object_shmem_init() describes the framebuffer's backing pages
to the host with sg_phys(). Those are guest-physical addresses. In a PV
domain they resolve, on the host side, to pages belonging to some other
domain, so the host scans out unrelated memory.
Move the decision into virtio_gpu_use_dma_api() and give it the
xen_domain() check, like vring_use_map_api() has. This
additionally enables the dma_sync_sgtable_for_device() calls in
virtgpu_vq.c, which are required for correctness whenever swiotlb
is in play.
Reproduced with a Xen 4.21 PV dom0 nested inside QEMU 8.2 with
virtio-vga, on both a distro 6.8 kernel and 6.18 LTS. A PVH dom0
works fine and doesn't need this fix because it is identity-mapped,
only PV dom0s are affected.
Fixes: a3b815f09b ("drm/virtio: add iommu support.")
Signed-off-by: Ben Leggett <benjamin@edera.io>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patch.msgid.link/20260806-virtgpu-xen-dma-v1-1-e499b345bbad@edera.io
virtio_gpu_free_vbufs() destroys the vbufs kmem_cache after the virtqueues
have already been released. Commands that were queued but never completed
by the device leave their vbuffers stranded in the virtqueue, so the cache
still holds live objects when virtio_gpu_deinit() tears everything down.
This triggers a WARNING in virtio_gpu_free_vbufs:
BUG virtio-gpu-vbufs (Not tainted): Objects remaining in cache
on __kmem_cache_shutdown()
Drain any buffers still sitting in the control and cursor virtqueues in
virtio_gpu_deinit() after the device has been reset and before the
virtqueues are deleted, following the same pattern used by virtio_console's
remove_vqs(). Each reclaimed buffer is released with free_vbuf(), dropping
the reference on any GEM objects it holds. Pending RESOURCE_UNREF
commands are handled as well: their resp_cb_data still references a GEM
object, so it is cleaned up with virtio_gpu_cleanup_object() to avoid
leaking it on teardown.
Reported-by: syzbot+06f9b2a53ba4a5a47644@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=06f9b2a53ba4a5a47644
Signed-off-by: Anuj Bolewar <bolewara@gmail.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patch.msgid.link/20260802-virtio-gpu-reclaim-vbufs-v2-1-5767fb860691@gmail.com
When scale is large enough that scaled_font exceeds the display
dimensions, rows or columns become 0. A columns value of 0 causes
an infinite loop in drm_log_draw_kmsg_record() because the loop
never decrements len.
Check for zero rows/columns in drm_log_setup_modeset() and return
an error, cleaning up the already allocated buffer to avoid a leak.
Fixes: 8a4b913df4 ("drm/log: Add integer scaling support")
Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patch.msgid.link/20260729084815.692944-1-oushixiong1025@163.com
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
The scale module parameter can be set to 0 via kernel command line.
When scale is 0, scaled_font_h and scaled_font_w become 0, causing
a division by zero in the rows/columns calculation.
Since the scale module parameter is read-only (0444 permissions), it
cannot be changed at runtime via sysfs. Clamp it to 1 once in
drm_log_register().
Fixes: 8a4b913df4 ("drm/log: Add integer scaling support")
Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patch.msgid.link/20260730014440.66323-1-oushixiong1025@163.com
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
aie2_populate_range() incorrectly failed jobs for BOs with multiple
mmaps: if the unmapped entry appeared first in umap_list, the loop would
pick it up, call hmm_range_fault() on a gone VMA, and return -EFAULT
without ever trying the remaining valid mapps.
Fix it by skipping unmapped entries. After the loop, if the map list is
empty or all maps are valid, map_invalid can be cleared normally.
Fixes: e486147c91 ("accel/amdxdna: Add BO import and export")
Reviewed-by: Max Zhen <max.zhen@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260812205628.810816-1-lizhi.hou@amd.com
Pull tracing fixes from Steven Rostedt:
- Fix use-after-free in eventfs_remove_rec()
The freeing of the eventfs_inode children used list_for_each_entry()
where the child is freed via srcu, but there's still a chance that it
gets freed. It should be using list_for_each_entry_safe().
- Fix eventfs_inode SRCU use of list in freeing
The iterator uses an SRCU protected list walk on the eventfs inodes.
The eventfs inode uses its "list" field in a union with the RCU list
head. When the inode gets added to the SRCU list it immediately
corrupts the list pointer and can cause an issue with the iterator.
Move the RCU list head to be shared with the children list head which
allows the iterator to check the parent inode if is freed before
referencing the child. Have the iterator check the parent "is_freed"
field and break out if it is set. Also add memory barriers to make
sure the ordering is correct.
- Fix various RCU synchronization issues with direct_functions
Updates to direct_functions have some missing RCU protection and
synchronization. Restructure the code a bit to make sure updates to
the direct_functions are protected.
- Remove an unneeded comma from a scope_guard()
There's a spurious comma in a scope_guard(). Remove it.
- Fix race in per CPU buffer swap in the ring buffer
When a per CPU buffer swap happens, it must make sure that it doesn't
occur while a writer is active. Instead it returns an -EBUSY. But
there's a small race window when a writer moves from one sub-buffer
to the next that it resets the "committing" counter. If a swap
happens at that moment, the buffer used for the commit of an event
will not match the buffer the event is actually on. Instead of using
the "committing" counter, use the recursive detection counter that
does not get reset when the writer crosses sub-buffers.
- Fix off-by-one in ftrace_free_mem()
The function ftrace_free_mem() gets an "end_ptr" as a parameter that
is exclusive to the rang to be freed. But its value is used to search
for the records that expects an inclusive value. Subtract one from
the parameter to convert it to an inclusive range.
- Disable resizing of the ring buffer for persistent buffers
Resizing the persistent buffer has undefined behavior. Prevent it
from being resized.
- Disable changing ring buffer subbuf order when resizing is disabled
The ring buffer subbuffer order can not be changed during resizing.
Use that instead of just checking if the buffer is mapped as mapped
buffers also have resizing disabled.
- Initialize subbuf_order of reader pages when they are created
In rb_allocate_cpu_buffer() the bpage->order is not updated to the
current subbuf_order leaving it as zero. This value is used when the
page is freed.
- Fix test_ringbuffer() to test for ERR_PTR before calling
kthread_stop()
The rb_threads[] array is assigned the output of kthread_run_on_cpu()
which could return an ERR_PTR. At the end of the test, all threads in
the array are cleaned up by kthread_stop() passing in the value in
the array if it isn't zero. But if the array contains an ERR_PTR,
kthread_stop() will not be able to handle it properly.
* tag 'trace-v7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Fix crash passing ERR_PTR to kthread_stop()
ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer()
ring-buffer: Prevent subbuf order change when resizing is disabled
ring-buffer: Prevent resizing of persistent ring buffer
ftrace: Fix off-by-one fentry site disable in ftrace_free_mem()
ring-buffer: Use current_context for safe per-CPU buffer swap
ftrace: Drop extra comma in trace_buffered_event_enable
ftrace: Protect direct_functions in update_ftrace_direct_mod
ftrace: Protect direct_functions in update_ftrace_direct_del
ftrace: Protect direct_functions in ftrace_find_rec_direct
eventfs: Use children field for rcu head and add memory barriers
eventfs: Fix use-after-free in eventfs_remove_rec()
Pull s390 fixes from Vasily Gorbik:
- Fix potential uninitialized memory reads and buffer overflows from
malformed zcrypt CCA and EP11 requests by properly validating lengths
and payloads
- Fix possible out of bounds accesses in zcrypt EP11 domain handling by
replacing fixed payload layout assumptions with parsing ASN.1 fields
with bounds checks
- Fix zcrypt CCA and EP11 request and reply buffer allocations missing
required 4-byte padding, and scrub the full allocation on release
- Fix zcrypt CCA and EP11 messages leaking up to 3 uninitialized bytes
of memory by zeroing trailing alignment padding
* tag 's390-7.2-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/zcrypt: Pad trailing CCA or EP11 message with zeros
s390/zcrypt: Improve EP11 CPRB domain handling with ASN.1 parsing
s390/zcrypt: Improve EP11 CPRB length and overflow checks
s390/zcrypt: Improve CCA CPRB length and overflow checks
s390/zcrypt: Fix CPRB memory allocation in zcrypt misc code
In test_ringbuffer()'s out_free cleanup loop, the check
`!rb_threads[cpu]` only catches NULL entries and misses entries that
hold an ERR_PTR.
rb_threads[] is static, so unassigned slots are NULL. But when
kthread_run_on_cpu() fails for a cpu, it stores ERR_PTR(-ENOMEM) (or
-EINTR) in rb_threads[cpu] before the creation loop jumps to out_free.
That entry is non-NULL, so the old `!ptr` check does not break, and the
cleanup proceeds to call kthread_stop() on the ERR_PTR. kthread_stop()
then dereferences the bogus pointer, crashing the kernel during the
late_initcall self-test.
crash logs:
BUG: kernel NULL pointer dereference, address: 000000000000001c
Oops: 0002 [#1] SMP NOPTI
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 7.2.0-rc6-dirty #7 PREEMPT(lazy)
RIP: 0010:kthread_stop+0x2e/0x220
RBX: fffffffffffffff4
CR2: 000000000000001c
Call Trace:
<TASK>
test_ringbuffer+0x1ec/0x650
do_one_initcall+0x6c/0x2c0
kernel_init_freeable+0x21d/0x420
kernel_init+0x15/0x1c0
ret_from_fork+0x21b/0x320
</TASK>
Kernel panic - not syncing: Fatal exception
Cc: stable@vger.kernel.org
Fixes: 64ed3a049e ("ring-buffer: make use of the helper function kthread_run_on_cpu()")
Link: https://patch.msgid.link/20260807154145.2846521-2-sh_def@163.com
Signed-off-by: Hui Su <sh_def@163.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
