LKML Archive on
help / color / mirror / Atom feed
* [PATCH 2.6.25-rc4] gigaset: fix Oops on module unload regression
@ 2008-03-07 18:47 Tilman Schmidt
  0 siblings, 0 replies; only message in thread
From: Tilman Schmidt @ 2008-03-07 18:47 UTC (permalink / raw)
  To: Linus Torvalds, Linux Kernel Mailing List
  Cc: Hansjoerg Lipp, Karsten Keil, Roland Kletzing

The card state mutex was only initialized when a device was connected,
but used during unload unconditionally, leading to an Oops if a driver
was loaded and unloaded again without ever connecting a device.

Fix this by initializing the mutex as soon as the structure is allocated.
Also add a missing mutex unlock revealed in the same execution path.

Thanks to Roland Kletzing for reporting this problem.

Signed-off-by: Tilman Schmidt <>
Tested-by: Roland Kletzing <>
Cc: Hansjoerg Lipp <>
Cc: Karsten Keil <>
This fixes a possible Oops in 2.6.25-rc that was introduced by commit
e468c04894f36045cf93d1384183a461014b6840 (Gigaset: permit module unload).
Please merge as a regression fix for 2.6.25.

 drivers/isdn/gigaset/common.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index aacedec..827c32c 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -637,7 +637,6 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
 		err("maximum number of devices exceeded");
 		return NULL;
-	mutex_init(&cs->mutex);
 	gig_dbg(DEBUG_INIT, "allocating bcs[0..%d]", channels - 1);
 	cs->bcs = kmalloc(channels * sizeof(struct bc_state), GFP_KERNEL);
@@ -898,8 +897,10 @@ int gigaset_shutdown(struct cardstate *cs)
-	if (!(cs->flags & VALID_MINOR))
+	if (!(cs->flags & VALID_MINOR)) {
+		mutex_unlock(&cs->mutex);
 		return -1;
+	}
 	cs->waiting = 1;
@@ -1086,6 +1087,7 @@ struct gigaset_driver *gigaset_initdriver(unsigned minor, unsigned minors,
 		drv->cs[i].driver = drv;
 		drv->cs[i].ops = drv->ops;
 		drv->cs[i].minor_index = i;
+		mutex_init(&drv->cs[i].mutex);
 	gigaset_if_initdriver(drv, procname, devname);

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2008-03-07 18:47 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-03-07 18:47 [PATCH 2.6.25-rc4] gigaset: fix Oops on module unload regression Tilman Schmidt

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).