Patch "pinctrl: fix deadlock in create_pinctrl() when handling -EPROBE_DEFER" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    pinctrl: fix deadlock in create_pinctrl() when handling -EPROBE_DEFER

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pinctrl-fix-deadlock-in-create_pinctrl-when-handling.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2bdf0c7dd95b2c8576450f9a31181d21e5ee2eee
Author: Hagar Hemdan <hagarhem@xxxxxxxxxx>
Date:   Tue Jun 4 08:58:38 2024 +0000

    pinctrl: fix deadlock in create_pinctrl() when handling -EPROBE_DEFER
    
    [ Upstream commit adec57ff8e66aee632f3dd1f93787c13d112b7a1 ]
    
    In create_pinctrl(), pinctrl_maps_mutex is acquired before calling
    add_setting(). If add_setting() returns -EPROBE_DEFER, create_pinctrl()
    calls pinctrl_free(). However, pinctrl_free() attempts to acquire
    pinctrl_maps_mutex, which is already held by create_pinctrl(), leading to
    a potential deadlock.
    
    This patch resolves the issue by releasing pinctrl_maps_mutex before
    calling pinctrl_free(), preventing the deadlock.
    
    This bug was discovered and resolved using Coverity Static Analysis
    Security Testing (SAST) by Synopsys, Inc.
    
    Fixes: 42fed7ba44e4 ("pinctrl: move subsystem mutex to pinctrl_dev struct")
    Suggested-by: Maximilian Heyne <mheyne@xxxxxxxxx>
    Signed-off-by: Hagar Hemdan <hagarhem@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240604085838.3344-1-hagarhem@xxxxxxxxxx
    Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 052894d3a2047..97b1fa3a5e78d 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1078,8 +1078,8 @@ static struct pinctrl *create_pinctrl(struct device *dev,
 		 * an -EPROBE_DEFER later, as that is the worst case.
 		 */
 		if (ret == -EPROBE_DEFER) {
-			pinctrl_free(p, false);
 			mutex_unlock(&pinctrl_maps_mutex);
+			pinctrl_free(p, false);
 			return ERR_PTR(ret);
 		}
 	}