The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b81ac4395bbeaf36e078dea1a48c02dd97b76235 Mon Sep 17 00:00:00 2001
From: Dan Vacura <w36195(a)motorola.com>
Date: Tue, 3 May 2022 15:10:38 -0500
Subject: [PATCH] usb: gadget: uvc: allow for application to cleanly shutdown
Several types of kernel panics can occur due to timing during the uvc
gadget removal. This appears to be a problem with gadget resources being
managed by both the client application's v4l2 open/close and the UDC
gadget bind/unbind. Since the concept of USB_GADGET_DELAYED_STATUS
doesn't exist for unbind, add a wait to allow for the application to
close out.
Some examples of the panics that can occur are:
<1>[ 1147.652313] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000028
<4>[ 1147.652510] Call trace:
<4>[ 1147.652514] usb_gadget_disconnect+0x74/0x1f0
<4>[ 1147.652516] usb_gadget_deactivate+0x38/0x168
<4>[ 1147.652520] usb_function_deactivate+0x54/0x90
<4>[ 1147.652524] uvc_function_disconnect+0x14/0x38
<4>[ 1147.652527] uvc_v4l2_release+0x34/0xa0
<4>[ 1147.652537] __fput+0xdc/0x2c0
<4>[ 1147.652540] ____fput+0x10/0x1c
<4>[ 1147.652545] task_work_run+0xe4/0x12c
<4>[ 1147.652549] do_notify_resume+0x108/0x168
<1>[ 282.950561][ T1472] Unable to handle kernel NULL pointer
dereference at virtual address 00000000000005b8
<6>[ 282.953111][ T1472] Call trace:
<6>[ 282.953121][ T1472] usb_function_deactivate+0x54/0xd4
<6>[ 282.953134][ T1472] uvc_v4l2_release+0xac/0x1e4
<6>[ 282.953145][ T1472] v4l2_release+0x134/0x1f0
<6>[ 282.953167][ T1472] __fput+0xf4/0x428
<6>[ 282.953178][ T1472] ____fput+0x14/0x24
<6>[ 282.953193][ T1472] task_work_run+0xac/0x130
<3>[ 213.410077][ T29] configfs-gadget gadget: uvc: Failed to queue
request (-108).
<1>[ 213.410116][ T29] Unable to handle kernel NULL pointer
dereference at virtual address 0000000000000003
<6>[ 213.413460][ T29] Call trace:
<6>[ 213.413474][ T29] uvcg_video_pump+0x1f0/0x384
<6>[ 213.413489][ T29] process_one_work+0x2a4/0x544
<6>[ 213.413502][ T29] worker_thread+0x350/0x784
<6>[ 213.413515][ T29] kthread+0x2ac/0x320
<6>[ 213.413528][ T29] ret_from_fork+0x10/0x30
Signed-off-by: Dan Vacura <w36195(a)motorola.com>
Cc: stable <stable(a)vger.kernel.org>
Link: https://lore.kernel.org/r/20220503201039.71720-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 71bb5e477dba..d37965867b23 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -890,13 +890,37 @@ static void uvc_function_unbind(struct usb_configuration *c,
{
struct usb_composite_dev *cdev = c->cdev;
struct uvc_device *uvc = to_uvc(f);
+ long wait_ret = 1;
uvcg_info(f, "%s()\n", __func__);
+ /* If we know we're connected via v4l2, then there should be a cleanup
+ * of the device from userspace either via UVC_EVENT_DISCONNECT or
+ * though the video device removal uevent. Allow some time for the
+ * application to close out before things get deleted.
+ */
+ if (uvc->func_connected) {
+ uvcg_dbg(f, "waiting for clean disconnect\n");
+ wait_ret = wait_event_interruptible_timeout(uvc->func_connected_queue,
+ uvc->func_connected == false, msecs_to_jiffies(500));
+ uvcg_dbg(f, "done waiting with ret: %ld\n", wait_ret);
+ }
+
device_remove_file(&uvc->vdev.dev, &dev_attr_function_name);
video_unregister_device(&uvc->vdev);
v4l2_device_unregister(&uvc->v4l2_dev);
+ if (uvc->func_connected) {
+ /* Wait for the release to occur to ensure there are no longer any
+ * pending operations that may cause panics when resources are cleaned
+ * up.
+ */
+ uvcg_warn(f, "%s no clean disconnect, wait for release\n", __func__);
+ wait_ret = wait_event_interruptible_timeout(uvc->func_connected_queue,
+ uvc->func_connected == false, msecs_to_jiffies(1000));
+ uvcg_dbg(f, "done waiting for release with ret: %ld\n", wait_ret);
+ }
+
usb_ep_free_request(cdev->gadget->ep0, uvc->control_req);
kfree(uvc->control_buf);
@@ -915,6 +939,7 @@ static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
mutex_init(&uvc->video.mutex);
uvc->state = UVC_STATE_DISCONNECTED;
+ init_waitqueue_head(&uvc->func_connected_queue);
opts = fi_to_f_uvc_opts(fi);
mutex_lock(&opts->lock);
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index c3607a32b986..886103a1fe9b 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -14,6 +14,7 @@
#include <linux/spinlock.h>
#include <linux/usb/composite.h>
#include <linux/videodev2.h>
+#include <linux/wait.h>
#include <media/v4l2-device.h>
#include <media/v4l2-dev.h>
@@ -129,6 +130,7 @@ struct uvc_device {
struct usb_function func;
struct uvc_video video;
bool func_connected;
+ wait_queue_head_t func_connected_queue;
/* Descriptors */
struct {
diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index a2c78690c5c2..fd8f73bb726d 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -253,10 +253,11 @@ uvc_v4l2_subscribe_event(struct v4l2_fh *fh,
static void uvc_v4l2_disable(struct uvc_device *uvc)
{
- uvc->func_connected = false;
uvc_function_disconnect(uvc);
uvcg_video_enable(&uvc->video, 0);
uvcg_free_buffers(&uvc->video.queue);
+ uvc->func_connected = false;
+ wake_up_interruptible(&uvc->func_connected_queue);
}
static int
From: Eric Biggers <ebiggers(a)google.com>
Tryng to rename a directory that has all following properties fails with
EINVAL and triggers the 'WARN_ON_ONCE(!fscrypt_has_encryption_key(dir))'
in f2fs_match_ci_name():
- The directory is casefolded
- The directory is encrypted
- The directory's encryption key is not yet set up
- The parent directory is *not* encrypted
The problem is incorrect handling of the lookup of ".." to get the
parent reference to update. fscrypt_setup_filename() treats ".." (and
".") specially, as it's never encrypted. It's passed through as-is, and
setting up the directory's key is not attempted. As the name isn't a
no-key name, f2fs treats it as a "normal" name and attempts a casefolded
comparison. That breaks the assumption of the WARN_ON_ONCE() in
f2fs_match_ci_name() which assumes that for encrypted directories,
casefolded comparisons only happen when the directory's key is set up.
We could just remove this WARN_ON_ONCE(). However, since casefolding is
always a no-op on "." and ".." anyway, let's instead just not casefold
these names. This results in the standard bytewise comparison.
Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")
Cc: <stable(a)vger.kernel.org> # v5.11+
Signed-off-by: Eric Biggers <ebiggers(a)google.com>
---
fs/f2fs/dir.c | 3 ++-
fs/f2fs/f2fs.h | 10 +++++-----
fs/f2fs/hash.c | 11 ++++++-----
3 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index a0e51937d92eb..d5bd7932fb642 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -82,7 +82,8 @@ int f2fs_init_casefolded_name(const struct inode *dir,
#if IS_ENABLED(CONFIG_UNICODE)
struct super_block *sb = dir->i_sb;
- if (IS_CASEFOLDED(dir)) {
+ if (IS_CASEFOLDED(dir) &&
+ !is_dot_dotdot(fname->usr_fname->name, fname->usr_fname->len)) {
fname->cf_name.name = f2fs_kmem_cache_alloc(f2fs_cf_name_slab,
GFP_NOFS, false, F2FS_SB(sb));
if (!fname->cf_name.name)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 492af5b96de19..e9e32bc814dfe 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -508,11 +508,11 @@ struct f2fs_filename {
#if IS_ENABLED(CONFIG_UNICODE)
/*
* For casefolded directories: the casefolded name, but it's left NULL
- * if the original name is not valid Unicode, if the directory is both
- * casefolded and encrypted and its encryption key is unavailable, or if
- * the filesystem is doing an internal operation where usr_fname is also
- * NULL. In all these cases we fall back to treating the name as an
- * opaque byte sequence.
+ * if the original name is not valid Unicode, if the original name is
+ * "." or "..", if the directory is both casefolded and encrypted and
+ * its encryption key is unavailable, or if the filesystem is doing an
+ * internal operation where usr_fname is also NULL. In all these cases
+ * we fall back to treating the name as an opaque byte sequence.
*/
struct fscrypt_str cf_name;
#endif
diff --git a/fs/f2fs/hash.c b/fs/f2fs/hash.c
index 3cb1e7a24740f..049ce50cec9b0 100644
--- a/fs/f2fs/hash.c
+++ b/fs/f2fs/hash.c
@@ -91,7 +91,7 @@ static u32 TEA_hash_name(const u8 *p, size_t len)
/*
* Compute @fname->hash. For all directories, @fname->disk_name must be set.
* For casefolded directories, @fname->usr_fname must be set, and also
- * @fname->cf_name if the filename is valid Unicode.
+ * @fname->cf_name if the filename is valid Unicode and is not "." or "..".
*/
void f2fs_hash_filename(const struct inode *dir, struct f2fs_filename *fname)
{
@@ -110,10 +110,11 @@ void f2fs_hash_filename(const struct inode *dir, struct f2fs_filename *fname)
/*
* If the casefolded name is provided, hash it instead of the
* on-disk name. If the casefolded name is *not* provided, that
- * should only be because the name wasn't valid Unicode, so fall
- * back to treating the name as an opaque byte sequence. Note
- * that to handle encrypted directories, the fallback must use
- * usr_fname (plaintext) rather than disk_name (ciphertext).
+ * should only be because the name wasn't valid Unicode or was
+ * "." or "..", so fall back to treating the name as an opaque
+ * byte sequence. Note that to handle encrypted directories,
+ * the fallback must use usr_fname (plaintext) rather than
+ * disk_name (ciphertext).
*/
WARN_ON_ONCE(!fname->usr_fname->name);
if (fname->cf_name.name) {
base-commit: c0d31ec6397d963d85a190996b4b74654ef32e1d
--
2.36.1