Module Name:    src
Committed By:   riastradh
Date:           Fri Aug 16 20:11:18 UTC 2024

Modified Files:
        src/sys/kern: subr_devsw.c

Log Message:
devsw(9): Don't leak devsw reference on open d_devtounit failure.

PR kern/56816: Deadlock: sleep during unloading module with
kernconfig_lock being held


To generate a diff of this commit:
cvs rdiff -u -r1.51 -r1.52 src/sys/kern/subr_devsw.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/kern/subr_devsw.c
diff -u src/sys/kern/subr_devsw.c:1.51 src/sys/kern/subr_devsw.c:1.52
--- src/sys/kern/subr_devsw.c:1.51	Wed Feb 15 13:12:45 2023
+++ src/sys/kern/subr_devsw.c	Fri Aug 16 20:11:18 2024
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_devsw.c,v 1.51 2023/02/15 13:12:45 riastradh Exp $	*/
+/*	$NetBSD: subr_devsw.c,v 1.52 2024/08/16 20:11:18 riastradh Exp $	*/
 
 /*-
  * Copyright (c) 2001, 2002, 2007, 2008 The NetBSD Foundation, Inc.
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.51 2023/02/15 13:12:45 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.52 2024/08/16 20:11:18 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_dtrace.h"
@@ -1181,10 +1181,15 @@ bdev_open(dev_t dev, int flag, int devty
 		 * reviewing them all to find and verify a common
 		 * pattern.
 		 */
-		if ((unit = (*d->d_devtounit)(dev)) == -1)
-			return ENXIO;
-		if ((dv = device_lookup_acquire(d->d_cfdriver, unit)) == NULL)
-			return ENXIO;
+		if ((unit = (*d->d_devtounit)(dev)) == -1) {
+			rv = ENXIO;
+			goto out;
+		}
+		if ((dv = device_lookup_acquire(d->d_cfdriver, unit)) ==
+		    NULL) {
+			rv = ENXIO;
+			goto out;
+		}
 		SDT_PROBE6(sdt, bdev, open, acquire,
 		    d, dev, flag, devtype, unit, dv);
 	}
@@ -1201,7 +1206,7 @@ bdev_open(dev_t dev, int flag, int devty
 		device_release(dv);
 	}
 
-	bdevsw_release(d, lc);
+out:	bdevsw_release(d, lc);
 
 	return rv;
 }
@@ -1412,10 +1417,15 @@ cdev_open(dev_t dev, int flag, int devty
 		 * reviewing them all to find and verify a common
 		 * pattern.
 		 */
-		if ((unit = (*d->d_devtounit)(dev)) == -1)
-			return ENXIO;
-		if ((dv = device_lookup_acquire(d->d_cfdriver, unit)) == NULL)
-			return ENXIO;
+		if ((unit = (*d->d_devtounit)(dev)) == -1) {
+			rv = ENXIO;
+			goto out;
+		}
+		if ((dv = device_lookup_acquire(d->d_cfdriver, unit)) ==
+		    NULL) {
+			rv = ENXIO;
+			goto out;
+		}
 		SDT_PROBE6(sdt, cdev, open, acquire,
 		    d, dev, flag, devtype, unit, dv);
 	}
@@ -1432,7 +1442,7 @@ cdev_open(dev_t dev, int flag, int devty
 		device_release(dv);
 	}
 
-	cdevsw_release(d, lc);
+out:	cdevsw_release(d, lc);
 
 	return rv;
 }

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