On Sun Mar 2 17:58:25 2025 +0300, Nikita Zhandarovich wrote:
> Syzbot reported [1] a warning prompted by a check in call_s_stream()
> that checks whether .s_stream() operation is warranted for unstarted
> or stopped subdevs.
>
> Add a simple fix in vimc_streamer_pipeline_terminate() ensuring that
> entities skip a call to .s_stream() unless they have been previously
> properly started.
>
> [1] Syzbot report:
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 5933 at drivers/media/v4l2-core/v4l2-subdev.c:460
> call_s_stream+0x2df/0x350 drivers/media/v4l2-core/v4l2-subdev.c:460
> Modules linked in:
> CPU: 0 UID: 0 PID: 5933 Comm: syz-executor330 Not tainted
> 6.13.0-rc2-syzkaller-00362-g2d8308bf5b67 #0
> ...
> Call Trace:
> <TASK>
> vimc_streamer_pipeline_terminate+0x218/0x320
> drivers/media/test-drivers/vimc/vimc-streamer.c:62
> vimc_streamer_pipeline_init
> drivers/media/test-drivers/vimc/vimc-streamer.c:101 [inline]
> vimc_streamer_s_stream+0x650/0x9a0
> drivers/media/test-drivers/vimc/vimc-streamer.c:203
> vimc_capture_start_streaming+0xa1/0x130
> drivers/media/test-drivers/vimc/vimc-capture.c:256
> vb2_start_streaming+0x15f/0x5a0
> drivers/media/common/videobuf2/videobuf2-core.c:1789
> vb2_core_streamon+0x2a7/0x450
> drivers/media/common/videobuf2/videobuf2-core.c:2348
> vb2_streamon drivers/media/common/videobuf2/videobuf2-v4l2.c:875 [inline]
> vb2_ioctl_streamon+0xf4/0x170
> drivers/media/common/videobuf2/videobuf2-v4l2.c:1118
> __video_do_ioctl+0xaf0/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3122
> video_usercopy+0x4d2/0x1620 drivers/media/v4l2-core/v4l2-ioctl.c:3463
> v4l2_ioctl+0x1ba/0x250 drivers/media/v4l2-core/v4l2-dev.c:366
> vfs_ioctl fs/ioctl.c:51 [inline]
> __do_sys_ioctl fs/ioctl.c:906 [inline]
> __se_sys_ioctl fs/ioctl.c:892 [inline]
> __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f2b85c01b19
> ...
>
> Reported-by: [email protected]
> Closes: https://syzkaller.appspot.com/bug?extid=5bcd7c809d365e14c4df
> Fixes: adc589d2a208 ("media: vimc: Add vimc-streamer for stream control")
> Cc: [email protected]
> Signed-off-by: Nikita Zhandarovich <[email protected]>
> Signed-off-by: Hans Verkuil <[email protected]>
Patch committed.
Thanks,
Hans Verkuil
drivers/media/test-drivers/vimc/vimc-streamer.c | 6 ++++++
1 file changed, 6 insertions(+)
---
diff --git a/drivers/media/test-drivers/vimc/vimc-streamer.c
b/drivers/media/test-drivers/vimc/vimc-streamer.c
index 807551a5143b..15d863f97cbf 100644
--- a/drivers/media/test-drivers/vimc/vimc-streamer.c
+++ b/drivers/media/test-drivers/vimc/vimc-streamer.c
@@ -59,6 +59,12 @@ static void vimc_streamer_pipeline_terminate(struct
vimc_stream *stream)
continue;
sd = media_entity_to_v4l2_subdev(ved->ent);
+ /*
+ * Do not call .s_stream() to stop an already
+ * stopped/unstarted subdev.
+ */
+ if (!v4l2_subdev_is_streaming(sd))
+ continue;
v4l2_subdev_call(sd, video, s_stream, 0);
}
}
