CVE-2025-68175 media: nxp: imx8-isi: Fix streaming cleanup on release
In the Linux kernel, the following vulnerability has been resolved:

media: nxp: imx8-isi: Fix streaming cleanup on release

The current implementation unconditionally calls
mxc_isi_video_cleanup_streaming() in mxc_isi_video_release(). This can
lead to situations where any release call (like from a simple
"v4l2-ctl -l") may release a currently streaming queue when called on
such a device.

This is reproducible on an i.MX8MP board by streaming from an ISI
capture device using gstreamer:

	gst-launch-1.0 -v v4l2src device=/dev/videoX ! \
	    video/x-raw,format=GRAY8,width=1280,height=800,framerate=1/120 ! \
	    fakesink

While this stream is running, querying the caps of the same device
provokes the error state:

	v4l2-ctl -l -d /dev/videoX

This results in the following trace:

[  155.452152] ------------[ cut here ]------------
[  155.452163] WARNING: CPU: 0 PID: 1708 at drivers/media/platform/nxp/imx8-isi/imx8-isi-pipe.c:713 mxc_isi_pipe_irq_handler+0x19c/0x1b0 [imx8_isi]
[  157.004248] Modules linked in: cfg80211 rpmsg_ctrl rpmsg_char rpmsg_tty virtio_rpmsg_bus rpmsg_ns rpmsg_core rfkill nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables mcp251x6
[  157.053499] CPU: 0 UID: 0 PID: 1708 Comm: python3 Not tainted 6.15.4-00114-g1f61ca5cad76 #1 PREEMPT
[  157.064369] Hardware name: imx8mp_board_01 (DT)
[  157.068205] pstate: 400000c5 (nZcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  157.075169] pc : mxc_isi_pipe_irq_handler+0x19c/0x1b0 [imx8_isi]
[  157.081195] lr : mxc_isi_pipe_irq_handler+0x38/0x1b0 [imx8_isi]
[  157.087126] sp : ffff800080003ee0
[  157.090438] x29: ffff800080003ee0 x28: ffff0000c3688000 x27: 0000000000000000
[  157.097580] x26: 0000000000000000 x25: ffff0000c1e7ac00 x24: ffff800081b5ad50
[  157.104723] x23: 00000000000000d1 x22: 0000000000000000 x21: ffff0000c25e4000
[  157.111866] x20: 0000000060000200 x19: ffff80007a0608d0 x18: 0000000000000000
[  157.119008] x17: ffff80006a4e3000 x16: ffff800080000000 x15: 0000000000000000
[  157.126146] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
[  157.133287] x11: 0000000000000040 x10: ffff0000c01445f0 x9 : ffff80007a053a38
[  157.140425] x8 : ffff0000c04004b8 x7 : 0000000000000000 x6 : 0000000000000000
[  157.147567] x5 : ffff0000c0400490 x4 : ffff80006a4e3000 x3 : ffff0000c25e4000
[  157.154706] x2 : 0000000000000000 x1 : ffff8000825c0014 x0 : 0000000060000200
[  157.161850] Call trace:
[  157.164296]  mxc_isi_pipe_irq_handler+0x19c/0x1b0 [imx8_isi] (P)
[  157.170319]  __handle_irq_event_percpu+0x58/0x218
[  157.175029]  handle_irq_event+0x54/0xb8
[  157.178867]  handle_fasteoi_irq+0xac/0x248
[  157.182968]  handle_irq_desc+0x48/0x68
[  157.186723]  generic_handle_domain_irq+0x24/0x38
[  157.191346]  gic_handle_irq+0x54/0x120
[  157.195098]  call_on_irq_stack+0x24/0x30
[  157.199027]  do_interrupt_handler+0x88/0x98
[  157.203212]  el0_interrupt+0x44/0xc0
[  157.206792]  __el0_irq_handler_common+0x18/0x28
[  157.211328]  el0t_64_irq_handler+0x10/0x20
[  157.215429]  el0t_64_irq+0x198/0x1a0
[  157.219009] ---[ end trace 0000000000000000 ]---

Address this issue by moving the streaming preparation and cleanup to
the vb2 .prepare_streaming() and .unprepare_streaming() operations. This
also simplifies the driver by allowing direct usage of the
vb2_ioctl_streamon() and vb2_ioctl_streamoff() helpers, and removal of
the manual cleanup from mxc_isi_video_release().
CVSS v3.1 score: 7.8