In the Linux kernel, the following vulnerability has been resolved:
drm/gem: Acquire references on GEM handles for framebuffers
A GEM handle can be released while the GEM buffer object is attached
to a DRM framebuffer. This leads to the release of the dma-buf backing
the buffer object, if any. [1] Trying to use the framebuffer in further
mode-setting operations leads to a segmentation fault. Most easily
happens with driver that use shadow planes for vmap-ing the dma-buf
during a page flip. An example is shown below.
[ 156.791968] ------------[ cut here ]------------
[ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430
[...]
[ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430
[ 157.043420] Call Trace:
[ 157.045898] <TASK>
[ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0
[ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0
[ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0
[ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710
[ 157.065567] ? dma_buf_vmap+0x224/0x430
[ 157.069446] ? __warn.cold+0x58/0xe4
[ 157.073061] ? dma_buf_vmap+0x224/0x430
[ 157.077111] ? report_bug+0x1dd/0x390
[ 157.080842] ? handle_bug+0x5e/0xa0
[ 157.084389] ? exc_invalid_op+0x14/0x50
[ 157.088291] ? asm_exc_invalid_op+0x16/0x20
[ 157.092548] ? dma_buf_vmap+0x224/0x430
[ 157.096663] ? dma_resv_get_singleton+0x6d/0x230
[ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10
[ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10
[ 157.110697] drm_gem_shmem_vmap+0x74/0x710
[ 157.114866] drm_gem_vmap+0xa9/0x1b0
[ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0
[ 157.123086] drm_gem_fb_vmap+0xab/0x300
[ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10
[ 157.133032] ? lockdep_init_map_type+0x19d/0x880
[ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0
[ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180
[ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40
[...]
[ 157.346424] ---[ end trace 0000000000000000 ]---
Acquiring GEM handles for the framebuffer's GEM buffer objects prevents
this from happening. The framebuffer's cleanup later puts the handle
references.
Commit 1a148af06000 ("drm/gem-shmem: Use dma_buf from GEM object
instance") triggers the segmentation fault easily by using the dma-buf
field more widely. The underlying issue with reference counting has
been present before.
v2:
- acquire the handle instead of the BO (Christian)
- fix comment style (Christian)
- drop the Fixes tag (Christian)
- rename err_ gotos
- add missing Link tag
In the Linux kernel, the following vulnerability has been resolved:
ASoC: SOF: Intel: hda: Use devm_kstrdup() to avoid memleak.
sof_pdata->tplg_filename can have address allocated by kstrdup()
and can be overwritten. Memory leak was detected with kmemleak:
unreferenced object 0xffff88812391ff60 (size 16):
comm "kworker/4:1", pid 161, jiffies 4294802931
hex dump (first 16 bytes):
73 6f 66 2d 68 64 61 2d 67 65 6e 65 72 69 63 00 sof-hda-generic.
backtrace (crc 4bf1675c):
__kmalloc_node_track_caller_noprof+0x49c/0x6b0
kstrdup+0x46/0xc0
hda_machine_select.cold+0x1de/0x12cf [snd_sof_intel_hda_generic]
sof_init_environment+0x16f/0xb50 [snd_sof]
sof_probe_continue+0x45/0x7c0 [snd_sof]
sof_probe_work+0x1e/0x40 [snd_sof]
process_one_work+0x894/0x14b0
worker_thread+0x5e5/0xfb0
kthread+0x39d/0x760
ret_from_fork+0x31/0x70
ret_from_fork_asm+0x1a/0x30
In the Linux kernel, the following vulnerability has been resolved:
drm/scheduler: signal scheduled fence when kill job
When an entity from application B is killed, drm_sched_entity_kill()
removes all jobs belonging to that entity through
drm_sched_entity_kill_jobs_work(). If application A's job depends on a
scheduled fence from application B's job, and that fence is not properly
signaled during the killing process, application A's dependency cannot be
cleared.
This leads to application A hanging indefinitely while waiting for a
dependency that will never be resolved. Fix this issue by ensuring that
scheduled fences are properly signaled when an entity is killed, allowing
dependent applications to continue execution.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Add basic validation for RAS header
If RAS header read from EEPROM is corrupted, it could result in trying
to allocate huge memory for reading the records. Add some validation to
header fields.
In the Linux kernel, the following vulnerability has been resolved:
video: screen_info: Relocate framebuffers behind PCI bridges
Apply PCI host-bridge window offsets to screen_info framebuffers. Fixes
invalid access to I/O memory.
Resources behind a PCI host bridge can be relocated by a certain offset
in the kernel's CPU address range used for I/O. The framebuffer memory
range stored in screen_info refers to the CPU addresses as seen during
boot (where the offset is 0). During boot up, firmware may assign a
different memory offset to the PCI host bridge and thereby relocating
the framebuffer address of the PCI graphics device as seen by the kernel.
The information in screen_info must be updated as well.
The helper pcibios_bus_to_resource() performs the relocation of the
screen_info's framebuffer resource (given in PCI bus addresses). The
result matches the I/O-memory resource of the PCI graphics device (given
in CPU addresses). As before, we store away the information necessary to
later update the information in screen_info itself.
Commit 78aa89d1dfba ("firmware/sysfb: Update screen_info for relocated
EFI framebuffers") added the code for updating screen_info. It is based
on similar functionality that pre-existed in efifb. Efifb uses a pointer
to the PCI resource, while the newer code does a memcpy of the region.
Hence efifb sees any updates to the PCI resource and avoids the issue.
v3:
- Only use struct pci_bus_region for PCI bus addresses (Bjorn)
- Clarify address semantics in commit messages and comments (Bjorn)
v2:
- Fixed tags (Takashi, Ivan)
- Updated information on efifb
In the Linux kernel, the following vulnerability has been resolved:
bus: mhi: ep: Update read pointer only after buffer is written
Inside mhi_ep_ring_add_element, the read pointer (rd_offset) is updated
before the buffer is written, potentially causing race conditions where
the host sees an updated read pointer before the buffer is actually
written. Updating rd_offset prematurely can lead to the host accessing
an uninitialized or incomplete element, resulting in data corruption.
Invoke the buffer write before updating rd_offset to ensure the element
is fully written before signaling its availability.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: fix GCC_GCC_PCIE_HOT_RST definition for WCN7850
GCC_GCC_PCIE_HOT_RST is wrongly defined for WCN7850, causing kernel crash
on some specific platforms.
Since this register is divergent for WCN7850 and QCN9274, move it to
register table to allow different definitions. Then correct the register
address for WCN7850 to fix this issue.
Note IPQ5332 is not affected as it is not PCIe based device.
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
In the Linux kernel, the following vulnerability has been resolved:
genirq/irq_sim: Initialize work context pointers properly
Initialize `ops` member's pointers properly by using kzalloc() instead of
kmalloc() when allocating the simulation work context. Otherwise the
pointers contain random content leading to invalid dereferencing.
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: Fix timeline left held on VMA alloc error
The following error has been reported sporadically by CI when a test
unbinds the i915 driver on a ring submission platform:
<4> [239.330153] ------------[ cut here ]------------
<4> [239.330166] i915 0000:00:02.0: [drm] drm_WARN_ON(dev_priv->mm.shrink_count)
<4> [239.330196] WARNING: CPU: 1 PID: 18570 at drivers/gpu/drm/i915/i915_gem.c:1309 i915_gem_cleanup_early+0x13e/0x150 [i915]
...
<4> [239.330640] RIP: 0010:i915_gem_cleanup_early+0x13e/0x150 [i915]
...
<4> [239.330942] Call Trace:
<4> [239.330944] <TASK>
<4> [239.330949] i915_driver_late_release+0x2b/0xa0 [i915]
<4> [239.331202] i915_driver_release+0x86/0xa0 [i915]
<4> [239.331482] devm_drm_dev_init_release+0x61/0x90
<4> [239.331494] devm_action_release+0x15/0x30
<4> [239.331504] release_nodes+0x3d/0x120
<4> [239.331517] devres_release_all+0x96/0xd0
<4> [239.331533] device_unbind_cleanup+0x12/0x80
<4> [239.331543] device_release_driver_internal+0x23a/0x280
<4> [239.331550] ? bus_find_device+0xa5/0xe0
<4> [239.331563] device_driver_detach+0x14/0x20
...
<4> [357.719679] ---[ end trace 0000000000000000 ]---
If the test also unloads the i915 module then that's followed with:
<3> [357.787478] =============================================================================
<3> [357.788006] BUG i915_vma (Tainted: G U W N ): Objects remaining on __kmem_cache_shutdown()
<3> [357.788031] -----------------------------------------------------------------------------
<3> [357.788204] Object 0xffff888109e7f480 @offset=29824
<3> [357.788670] Allocated in i915_vma_instance+0xee/0xc10 [i915] age=292729 cpu=4 pid=2244
<4> [357.788994] i915_vma_instance+0xee/0xc10 [i915]
<4> [357.789290] init_status_page+0x7b/0x420 [i915]
<4> [357.789532] intel_engines_init+0x1d8/0x980 [i915]
<4> [357.789772] intel_gt_init+0x175/0x450 [i915]
<4> [357.790014] i915_gem_init+0x113/0x340 [i915]
<4> [357.790281] i915_driver_probe+0x847/0xed0 [i915]
<4> [357.790504] i915_pci_probe+0xe6/0x220 [i915]
...
Closer analysis of CI results history has revealed a dependency of the
error on a few IGT tests, namely:
- igt@api_intel_allocator@fork-simple-stress-signal,
- igt@api_intel_allocator@two-level-inception-interruptible,
- igt@gem_linear_blits@interruptible,
- igt@prime_mmap_coherency@ioctl-errors,
which invisibly trigger the issue, then exhibited with first driver unbind
attempt.
All of the above tests perform actions which are actively interrupted with
signals. Further debugging has allowed to narrow that scope down to
DRM_IOCTL_I915_GEM_EXECBUFFER2, and ring_context_alloc(), specific to ring
submission, in particular.
If successful then that function, or its execlists or GuC submission
equivalent, is supposed to be called only once per GEM context engine,
followed by raise of a flag that prevents the function from being called
again. The function is expected to unwind its internal errors itself, so
it may be safely called once more after it returns an error.
In case of ring submission, the function first gets a reference to the
engine's legacy timeline and then allocates a VMA. If the VMA allocation
fails, e.g. when i915_vma_instance() called from inside is interrupted
with a signal, then ring_context_alloc() fails, leaving the timeline held
referenced. On next I915_GEM_EXECBUFFER2 IOCTL, another reference to the
timeline is got, and only that last one is put on successful completion.
As a consequence, the legacy timeline, with its underlying engine status
page's VMA object, is still held and not released on driver unbind.
Get the legacy timeline only after successful allocation of the context
engine's VMA.
v2: Add a note on other submission methods (Krzysztof Karas):
Both execlists and GuC submission use lrc_alloc() which seems free
from a similar issue.
(cherry picked from commit cc43422b3cc79eacff4c5a8ba0d224688ca9dd4f)