--- /dev/null
+From c0a40097f0bc81deafc15f9195d1fb54595cd6d0 Mon Sep 17 00:00:00 2001
+From: Dirk Behme <dirk.behme@de.bosch.com>
+Date: Mon, 13 May 2024 07:06:34 +0200
+Subject: drivers: core: synchronize really_probe() and dev_uevent()
+
+From: Dirk Behme <dirk.behme@de.bosch.com>
+
+commit c0a40097f0bc81deafc15f9195d1fb54595cd6d0 upstream.
+
+Synchronize the dev->driver usage in really_probe() and dev_uevent().
+These can run in different threads, what can result in the following
+race condition for dev->driver uninitialization:
+
+Thread #1:
+==========
+
+really_probe() {
+...
+probe_failed:
+...
+device_unbind_cleanup(dev) {
+ ...
+ dev->driver = NULL; // <= Failed probe sets dev->driver to NULL
+ ...
+ }
+...
+}
+
+Thread #2:
+==========
+
+dev_uevent() {
+...
+if (dev->driver)
+ // If dev->driver is NULLed from really_probe() from here on,
+ // after above check, the system crashes
+ add_uevent_var(env, "DRIVER=%s", dev->driver->name);
+...
+}
+
+really_probe() holds the lock, already. So nothing needs to be done
+there. dev_uevent() is called with lock held, often, too. But not
+always. What implies that we can't add any locking in dev_uevent()
+itself. So fix this race by adding the lock to the non-protected
+path. This is the path where above race is observed:
+
+ dev_uevent+0x235/0x380
+ uevent_show+0x10c/0x1f0 <= Add lock here
+ dev_attr_show+0x3a/0xa0
+ sysfs_kf_seq_show+0x17c/0x250
+ kernfs_seq_show+0x7c/0x90
+ seq_read_iter+0x2d7/0x940
+ kernfs_fop_read_iter+0xc6/0x310
+ vfs_read+0x5bc/0x6b0
+ ksys_read+0xeb/0x1b0
+ __x64_sys_read+0x42/0x50
+ x64_sys_call+0x27ad/0x2d30
+ do_syscall_64+0xcd/0x1d0
+ entry_SYSCALL_64_after_hwframe+0x77/0x7f
+
+Similar cases are reported by syzkaller in
+
+https://syzkaller.appspot.com/bug?extid=ffa8143439596313a85a
+
+But these are regarding the *initialization* of dev->driver
+
+dev->driver = drv;
+
+As this switches dev->driver to non-NULL these reports can be considered
+to be false-positives (which should be "fixed" by this commit, as well,
+though).
+
+The same issue was reported and tried to be fixed back in 2015 in
+
+https://lore.kernel.org/lkml/1421259054-2574-1-git-send-email-a.sangwan@samsung.com/
+
+already.
+
+Fixes: 239378f16aa1 ("Driver core: add uevent vars for devices of a class")
+Cc: stable <stable@kernel.org>
+Cc: syzbot+ffa8143439596313a85a@syzkaller.appspotmail.com
+Cc: Ashish Sangwan <a.sangwan@samsung.com>
+Cc: Namjae Jeon <namjae.jeon@samsung.com>
+Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
+Link: https://lore.kernel.org/r/20240513050634.3964461-1-dirk.behme@de.bosch.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/base/core.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/drivers/base/core.c
++++ b/drivers/base/core.c
+@@ -1273,8 +1273,11 @@ static ssize_t uevent_show(struct device
+ if (!env)
+ return -ENOMEM;
+
++ /* Synchronize with really_probe() */
++ device_lock(dev);
+ /* let the kset specific function add its keys */
+ retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
++ device_unlock(dev);
+ if (retval)
+ goto out;
+
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
- drivers/net/ethernet/pensando/ionic/ionic_lif.c | 4 +---
+ drivers/net/ethernet/pensando/ionic/ionic_lif.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
-diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
-index e7d868da6a380..7adad91617d8c 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
-@@ -205,10 +205,8 @@ static int ionic_qcq_enable(struct ionic_qcq *qcq)
+@@ -205,10 +205,8 @@ static int ionic_qcq_enable(struct ionic
if (ret)
return ret;
irq_set_affinity_hint(qcq->intr.vector,
&qcq->intr.affinity_mask);
ionic_intr_mask(idev->intr_ctrl, qcq->intr.index,
---
-2.43.0
-