CVE-2025-68175: Undefined Security Weakness

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().