diff options
| author | Minu Jin <s9430939@naver.com> | 2026-02-05 11:16:20 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-02-07 13:05:14 +0100 |
| commit | 54911107352dfe04b56828dd9f81fd570c1b76b0 (patch) | |
| tree | 773193d724010724ec0d7d639273bc421da6060d /drivers/staging/most | |
| parent | ad3521dc9c2f9b369f57de1bbcc14f85458a3828 (diff) | |
staging: most: video: fix potential race in list iteration
There is a pattern in the loops where the lock is dropped
to call a specific function and then re-acquired.
The list can be exposed during this short gap, creating a potential
race condition. This patch fixes the problem by replacing the list
head with a local free list using list_replace_init(), instead of
using the lock/unlock pattern in the loop.
Signed-off-by: Minu Jin <s9430939@naver.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/20260205021620.1165137-1-s9430939@naver.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/most')
| -rw-r--r-- | drivers/staging/most/video/video.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/drivers/staging/most/video/video.c b/drivers/staging/most/video/video.c index 32f71d9a9cf7..8eeae209ff1c 100644 --- a/drivers/staging/most/video/video.c +++ b/drivers/staging/most/video/video.c @@ -121,6 +121,7 @@ static int comp_vdev_close(struct file *filp) struct comp_fh *fh = to_comp_fh(filp); struct most_video_dev *mdev = fh->mdev; struct mbo *mbo, *tmp; + LIST_HEAD(free_list); /* * We need to put MBOs back before we call most_stop_channel() @@ -133,13 +134,14 @@ static int comp_vdev_close(struct file *filp) spin_lock_irq(&mdev->list_lock); mdev->mute = true; - list_for_each_entry_safe(mbo, tmp, &mdev->pending_mbos, list) { - list_del(&mbo->list); - spin_unlock_irq(&mdev->list_lock); + list_replace_init(&mdev->pending_mbos, &free_list); + spin_unlock_irq(&mdev->list_lock); + + list_for_each_entry_safe(mbo, tmp, &free_list, list) { + list_del_init(&mbo->list); most_put_mbo(mbo); - spin_lock_irq(&mdev->list_lock); } - spin_unlock_irq(&mdev->list_lock); + most_stop_channel(mdev->iface, mdev->ch_idx, &comp); mdev->mute = false; @@ -554,6 +556,7 @@ static int __init comp_init(void) static void __exit comp_exit(void) { struct most_video_dev *mdev, *tmp; + LIST_HEAD(free_list); /* * As the mostcore currently doesn't call disconnect_channel() @@ -562,16 +565,15 @@ static void __exit comp_exit(void) * This must be fixed in core. */ spin_lock_irq(&list_lock); - list_for_each_entry_safe(mdev, tmp, &video_devices, list) { - list_del(&mdev->list); - spin_unlock_irq(&list_lock); + list_replace_init(&video_devices, &free_list); + spin_unlock_irq(&list_lock); + list_for_each_entry_safe(mdev, tmp, &free_list, list) { + list_del_init(&mdev->list); comp_unregister_videodev(mdev); v4l2_device_disconnect(&mdev->v4l2_dev); v4l2_device_put(&mdev->v4l2_dev); - spin_lock_irq(&list_lock); } - spin_unlock_irq(&list_lock); most_deregister_configfs_subsys(&comp); most_deregister_component(&comp); |