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>
When a module's init text is freed, do_init_module() calls
ftrace_free_mem() with a half-open [start, end) range. However the
ftrace_cmp_recs() comparator treats the upper bound as inclusive, as all
its other users do, passing 'ip + size - 1'. So ftrace_free_mem() can
delete a record sitting exactly at 'end', which is outside the freed
range.
For a kernel without CFI or IBT, the first record of a function is at
the function start, which for the first function in a module is also the
base of its text allocation. As the module allocator packs its regions,
that address is often the 'end' passed by a neighboring module's
do_init_module(), causing the first function's ftrace location to get
disabled, preventing an attempt to livepatch it:
livepatch: failed to find location for function 'pcspkr_probe'
Convert the exclusive end to the inclusive 'end - 1' the comparator
expects, and return early for an empty range to avoid the subtraction
from underflowing when the init text size is zero.
Cc: stable@vger.kernel.org
Fixes: 42c269c88d ("ftrace: Allow for function tracing to record init functions on boot up")
Link: https://patch.msgid.link/1b5ccfa8095bdb1277f84af1c2c2e2205aca03ae.1785992188.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ring_buffer_swap_cpu() function currently checks the per-CPU
committing counter to determine if a buffer is actively being written to
before performing the swap. However, there exists a race window where
this check can be bypassed:
ring_buffer_lock_reserve
cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_a
rb_reserve_next_event
rb_start_commit // inc committing
if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...}
__rb_reserve_next
rb_move_tail
rb_end_commit(cpu_buffer); // dec committing => 0
/* interrupt hits here, successfully swaps! */
local_inc(&cpu_buffer->committing);
ring_buffer_unlock_commit
cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_b
rb_commit
rb_end_commit
RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing))
// triggers warning
The committing counter can temporarily drop to 0 during a single write
operation (within rb_move_tail), creating a window where swap can
succeed even though the write is still in progress. This leads to
inconsistent buffer state and triggers the RB_WARN_ON in rb_commit().
Replace the committing counter check with current_context checks, which
are set at the entry of ring_buffer_lock_reserve() and remain valid
throughout the entire write operation, providing a reliable indicator of
buffer busy state during swap.
Cc: stable@vger.kernel.org
Fixes: 4239c38fe0 ("ring-buffer: Process commits whenever moving to a new page.")
Link: https://patch.msgid.link/20260803005640.2445666-2-wutengda@huaweicloud.com
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull x86 fix from Ingo Molnar:
- Fix MCE CMCI discovery initialization ordering bug (Breno Leitao)
* tag 'x86-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Set up the polling timer before CMCI discovery
Pull futex fix from Ingo Molnar:
- Fix race in futex_pivot_pending() during private hash resize
that can cause stuck tasks (Yao Kai)
* tag 'locking-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Fix race in futex_pivot_pending() during private hash resize
Pull USB / Thunderbolt fixes from Greg KH:
"Here are some small USB and Thunderbolt driver fixes for 7.2-rc7 that
resolve some reported issues. Included in here are:
- new quirk for some broken USB devices
- thunderbolt device fixes for reported issues
- usb gadget driver fix
- usb atm driver fix
- xhci driver fixes.
- other minor USB driver fixes
All of these have been in linux-next this week with no reported
issues"
* tag 'usb-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: xhci: use BIT_ULL for CRCR bits to fix incorrect 64bit mask
usb: quirks: Add ShanWan gamepad to quirk list
usb: hub: Split announce_device() to log device identity before enumeration
usb: core: Add quirk for 255-bytes initial config read
usb: atm: cxacru: properly kill rcv_urb on error in cxacru_cm()
usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg
usb: gadget: f_ncm: Use unsigned int for ndp_index
usb: cdnsp: fix incorrect endian conversions for APB timeout register
thunderbolt: Initialize ->domain_released completion before it is being used
thunderbolt: icm: Preserve USB4 proxy data-valid bit
thunderbolt: Bound the DROM dual link port number before indexing sw->ports
thunderbolt: Fix bandwidth group reservation indexing
thunderbolt: stream: Unmap buffers with mapped size
Pull tty / serial / vt driver fixes from Greg KH:
"Here are some small serial and vt tty driver fixes for 7.2-rc7 that
resolve some reported problems. Included in here are:
- two vt core fixes
- amba-pl011 serial driver fixes
- 8250_of and 8250_dma driver fixes
- qcom-geni serial driver fix
- sc16is7xx serial driver fix
All of these have been in linux-next this week with no reported
issues"
* tag 'tty-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: amba-pl011: synchronize DMA teardown
serial: amba-pl011: cancel RS485 hrtimers after freeing IRQ
serial: amba-pl011: fix indefinite RS485 post-send delay
vt: add permission check for KDSKBMETA ioctl
vt: stabilize tty reference in kbd_keycode with tty_port_tty_get
serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx
serial: qcom-geni: fix TX DMA buffer flush
serial: 8250_dma: Clear stale RX state on shutdown
serial: sc16is7xx: enable THRI before filling TX FIFO
Pull staging driver fixes from Greg KH:
"Here are some more small staging driver fixes, just for the rtl8723bs
driver, for some reported problems found with it now that people are
starting to actually test the thing with "bad" networks.
Nothing major, but good to have in the -final release. All of these
have been in linux-next for over a week with no reported problems"
* tag 'staging-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: rtl8723bs: validate monitor transmit frame lengths
staging: rtl8723bs: fix missing shared-key auth challenge length check
staging: rtl8723bs: fix OOB read in WMM_param_handler()
staging: rtl8723bs: fix OOB read in rtw_get_wpa_ie()
Pull char / misc and documentation fixes from Greg KH:
"Here are some small char/misc and nvmem and documentation fixes for
7.2-rc7 to resolve some reported issues. Included in here are:
- updates to the documentation for the kernel threat model and
security bugs to get the LLMs to actually follow what we have been
asking them to do (i.e. not claim security issues for things we do
not consider security issues.)
- nvmem driver fixes which required a tiny "layout" driver to be
added.
- fastrpc driver fixes
- mei driver fix
- counter driver fix
- binder driver fix
All of these have been in linux-next this week with no reported
problems"
* tag 'char-misc-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
docs: security-bugs: clarify some mandatory steps for AI reports
docs: coding-assistant: explain important steps when looking for bugs
docs: security-bugs: clarify what counts as a valid version
docs: threat-model: move fake devices out of "non production use"
docs: threat-model: clarify "security bug" vs "vulnerability"
counter: microchip-tcb-capture: Fix DT channel validation
mei: pull kvfree out of spinlock
rust_binder: do not query current thread for all ioctls
nvmem: layouts: Add fixed-layout driver
nvmem: apple-spmi-nvmem: wrap regmap calls to satisfy CFI
misc: fastrpc: fix memory leak in fastrpc_channel_ctx_free
misc: fastrpc: fix channel ctx ref leak when session alloc fails
misc: fastrpc: take fl->lock when moving mmaps on interrupted invoke
misc: fastrpc: Remove buffer from list prior to unmap operation
misc: fastrpc: Fix initial memory allocation for Audio PD memory pool
Pull fbdev fixes from Helge Deller:
"A few patches for the core fbdev layer which stabilize or fix
potential issues with text font rendering after screen rotation or
after user initiated font changes and locking fixes for sysfb during
modifications of the graphics mode database"
* tag 'fbdev-for-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
fbdev: bitblit: bound-check glyph index in bit_cursor()
fbdev: Fix out-of-bounds access when rotating console after font resize
fbdev: core: Fix pointer desynchronization in fb_io_read()
fbdev: serialize mode sysfs access with lock_fb_info()
fbdev: clear fb_info->mode before deleting a videomode
fbdev: bound mode sysfs output to the sysfs buffer
