ACK/Cmnt: [SRU][N][PATCH 0/1] CVE-2024-35990

[Bethany Jamison]

Sorry I should be more clear about this -- it's been applied to 
master-next (5.15.0-115.125).

On 6/28/24 8:22 AM, Stefan Bader wrote:
> On 26.06.24 16:45, Bethany Jamison wrote:
>> [Impact]
>>
>> dma: xilinx_dpdma: Fix locking
>>
>> There are several places where either chan->lock or chan->vchan.lock was
>> not held. Add appropriate locking. This fixes lockdep warnings like
>>
>> [   31.077578] ------------[ cut here ]------------
>> [   31.077831] WARNING: CPU: 2 PID: 40 at 
>> drivers/dma/xilinx/xilinx_dpdma.c:834 
>> xilinx_dpdma_chan_queue_transfer+0x274/0x5e0
>> [   31.077953] Modules linked in:
>> [   31.078019] CPU: 2 PID: 40 Comm: kworker/u12:1 Not tainted 6.6.20+ 
>> #98
>> [   31.078102] Hardware name: xlnx,zynqmp (DT)
>> [   31.078169] Workqueue: events_unbound deferred_probe_work_func
>> [   31.078272] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS 
>> BTYPE=--)
>> [   31.078377] pc : xilinx_dpdma_chan_queue_transfer+0x274/0x5e0
>> [   31.078473] lr : xilinx_dpdma_chan_queue_transfer+0x270/0x5e0
>> [   31.078550] sp : ffffffc083bb2e10
>> [   31.078590] x29: ffffffc083bb2e10 x28: 0000000000000000 x27: 
>> ffffff880165a168
>> [   31.078754] x26: ffffff880164e920 x25: ffffff880164eab8 x24: 
>> ffffff880164d480
>> [   31.078920] x23: ffffff880165a148 x22: ffffff880164e988 x21: 
>> 0000000000000000
>> [   31.079132] x20: ffffffc082aa3000 x19: ffffff880164e880 x18: 
>> 0000000000000000
>> [   31.079295] x17: 0000000000000000 x16: 0000000000000000 x15: 
>> 0000000000000000
>> [   31.079453] x14: 0000000000000000 x13: ffffff8802263dc0 x12: 
>> 0000000000000001
>> [   31.079613] x11: 0001ffc083bb2e34 x10: 0001ff880164e98f x9 : 
>> 0001ffc082aa3def
>> [   31.079824] x8 : 0001ffc082aa3dec x7 : 0000000000000000 x6 : 
>> 0000000000000516
>> [   31.079982] x5 : ffffffc7f8d43000 x4 : ffffff88003c9c40 x3 : 
>> ffffffffffffffff
>> [   31.080147] x2 : ffffffc7f8d43000 x1 : 00000000000000c0 x0 : 
>> 0000000000000000
>> [   31.080307] Call trace:
>> [   31.080340]  xilinx_dpdma_chan_queue_transfer+0x274/0x5e0
>> [   31.080518]  xilinx_dpdma_issue_pending+0x11c/0x120
>> [   31.080595]  zynqmp_disp_layer_update+0x180/0x3ac
>> [   31.080712]  zynqmp_dpsub_plane_atomic_update+0x11c/0x21c
>> [   31.080825]  drm_atomic_helper_commit_planes+0x20c/0x684
>> [   31.080951]  drm_atomic_helper_commit_tail+0x5c/0xb0
>> [   31.081139]  commit_tail+0x234/0x294
>> [   31.081246]  drm_atomic_helper_commit+0x1f8/0x210
>> [   31.081363]  drm_atomic_commit+0x100/0x140
>> [   31.081477]  drm_client_modeset_commit_atomic+0x318/0x384
>> [   31.081634]  drm_client_modeset_commit_locked+0x8c/0x24c
>> [   31.081725]  drm_client_modeset_commit+0x34/0x5c
>> [   31.081812] __drm_fb_helper_restore_fbdev_mode_unlocked+0x104/0x168
>> [   31.081899]  drm_fb_helper_set_par+0x50/0x70
>> [   31.081971]  fbcon_init+0x538/0xc48
>> [   31.082047]  visual_init+0x16c/0x23c
>> [   31.082207]  do_bind_con_driver.isra.0+0x2d0/0x634
>> [   31.082320]  do_take_over_console+0x24c/0x33c
>> [   31.082429]  do_fbcon_takeover+0xbc/0x1b0
>> [   31.082503]  fbcon_fb_registered+0x2d0/0x34c
>> [   31.082663]  register_framebuffer+0x27c/0x38c
>> [   31.082767] __drm_fb_helper_initial_config_and_unlock+0x5c0/0x91c
>> [   31.082939]  drm_fb_helper_initial_config+0x50/0x74
>> [   31.083012]  drm_fbdev_dma_client_hotplug+0xb8/0x108
>> [   31.083115]  drm_client_register+0xa0/0xf4
>> [   31.083195]  drm_fbdev_dma_setup+0xb0/0x1cc
>> [   31.083293]  zynqmp_dpsub_drm_init+0x45c/0x4e0
>> [   31.083431]  zynqmp_dpsub_probe+0x444/0x5e0
>> [   31.083616]  platform_probe+0x8c/0x13c
>> [   31.083713]  really_probe+0x258/0x59c
>> [   31.083793]  __driver_probe_device+0xc4/0x224
>> [   31.083878]  driver_probe_device+0x70/0x1c0
>> [   31.083961]  __device_attach_driver+0x108/0x1e0
>> [   31.084052]  bus_for_each_drv+0x9c/0x100
>> [   31.084125]  __device_attach+0x100/0x298
>> [   31.084207]  device_initial_probe+0x14/0x20
>> [   31.084292]  bus_probe_device+0xd8/0xdc
>> [   31.084368]  deferred_probe_work_func+0x11c/0x180
>> [   31.084451]  process_one_work+0x3ac/0x988
>> [   31.084643]  worker_thread+0x398/0x694
>> [   31.084752]  kthread+0x1bc/0x1c0
>> [   31.084848]  ret_from_fork+0x10/0x20
>> [   31.084932] irq event stamp: 64549
>> [   31.084970] hardirqs last  enabled at (64548): 
>> [<ffffffc081adf35c>] _raw_spin_unlock_irqrestore+0x80/0x90
>> [   31.085157] hardirqs last disabled at (64549): 
>> [<ffffffc081adf010>] _raw_spin_lock_irqsave+0xc0/0xdc
>> [   31.085277] softirqs last  enabled at (64503): 
>> [<ffffffc08001071c>] __do_softirq+0x47c/0x500
>> [   31.085390] softirqs last disabled at (64498): 
>> [<ffffffc080017134>] ____do_softirq+0x10/0x1c
>> [   31.085501] ---[ end trace 0000000000000000 ]---
>>
>> [Fix]
>>
>> Noble:    Clean cherry-pick from linux-6.8.y
>> Jammy:    pending
>
> Which kind of pending is this? Applied to jammy:linux/master-next 
> already or pending to be processed?
>
>> Focal:    not affected
>> Bionic: not affected
>> Xenial:    not affected
>> Trusty:    not affected
>>
>> [Test Case]
>>
>> Compile and boot tested
>>
>> [Where problems could occur]
>>
>> This fix affects those who use the Xilinx ZynqMP DPDMA Engine
>> driver, an issue with this fix would be visible to the user via
>> unexpected system behavior.
>>
>> Sean Anderson (1):
>>    dma: xilinx_dpdma: Fix locking
>>
>>   drivers/dma/xilinx/xilinx_dpdma.c | 13 ++++++++++---
>>   1 file changed, 10 insertions(+), 3 deletions(-)
>>
>
> Acked-by: Stefan Bader <stefan.bader at canonical.com>