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| author | Andrei Kuchynski <akuchynski@chromium.org> | 2025-06-24 13:32:46 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-10 16:08:54 +0200 |
| commit | 80c25d7916a44715338d4f8924c8e52af50d0b9f (patch) | |
| tree | dcaffa7dcc9a200e506df5899fb593d79e0901a3 | |
| parent | 8ca9c0f5881de0c51f2f6f645f7eb8e84d8ce3e1 (diff) | |
| download | linux-80c25d7916a44715338d4f8924c8e52af50d0b9f.tar.gz linux-80c25d7916a44715338d4f8924c8e52af50d0b9f.tar.bz2 linux-80c25d7916a44715338d4f8924c8e52af50d0b9f.zip | |
usb: typec: displayport: Fix potential deadlock
commit 099cf1fbb8afc3771f408109f62bdec66f85160e upstream.
The deadlock can occur due to a recursive lock acquisition of
`cros_typec_altmode_data::mutex`.
The call chain is as follows:
1. cros_typec_altmode_work() acquires the mutex
2. typec_altmode_vdm() -> dp_altmode_vdm() ->
3. typec_altmode_exit() -> cros_typec_altmode_exit()
4. cros_typec_altmode_exit() attempts to acquire the mutex again
To prevent this, defer the `typec_altmode_exit()` call by scheduling
it rather than calling it directly from within the mutex-protected
context.
Cc: stable <stable@kernel.org>
Fixes: b4b38ffb38c9 ("usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode")
Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250624133246.3936737-1-akuchynski@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/typec/altmodes/displayport.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c index 773786129dfb..d8b906ec4d1c 100644 --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -394,8 +394,7 @@ static int dp_altmode_vdm(struct typec_altmode *alt, case CMDT_RSP_NAK: switch (cmd) { case DP_CMD_STATUS_UPDATE: - if (typec_altmode_exit(alt)) - dev_err(&dp->alt->dev, "Exit Mode Failed!\n"); + dp->state = DP_STATE_EXIT; break; case DP_CMD_CONFIGURE: dp->data.conf = 0; |