[PATCH 6.1.y] driver core: bus: Fix double free in driver API bus_register()

[PATCH 6.1.y] driver core: bus: Fix double free in driver API bus_register()

[jianqi.ren.cn]

From: Zijun Hu <quic_zijuhu@quicinc.com>

[ Upstream commit bfa54a793ba77ef696755b66f3ac4ed00c7d1248 ]

For bus_register(), any error which happens after kset_register() will
cause that @priv are freed twice, fixed by setting @priv with NULL after
the first free.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240727-bus_register_fix-v1-1-fed8dd0dba7a@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Using bus->p instead of priv which will be consistent with the context ]
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
---
 drivers/base/bus.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 339a9edcde5f..028e45d2f7fe 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -853,6 +853,8 @@ int bus_register(struct bus_type *bus)
 	bus_remove_file(bus, &bus_attr_uevent);
 bus_uevent_fail:
 	kset_unregister(&bus->p->subsys);
+	/* Above kset_unregister() will kfree @priv */
+	bus->p = NULL;
 out:
 	kfree(bus->p);
 	bus->p = NULL;
-- 
2.25.1

Re: [PATCH 6.1.y] driver core: bus: Fix double free in driver API bus_register()

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: bfa54a793ba77ef696755b66f3ac4ed00c7d1248

WARNING: Author mismatch between patch and upstream commit:
Backport author: <jianqi.ren.cn@windriver.com>
Commit author: Zijun Hu <quic_zijuhu@quicinc.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: d885c464c250)
6.1.y | Present (different SHA1: 25d339a6e63b)

Note: The patch differs from the upstream commit:
---
1:  bfa54a793ba77 < -:  ------------- driver core: bus: Fix double free in driver API bus_register()
-:  ------------- > 1:  eda23201cf4ef driver core: bus: Fix double free in driver API bus_register()
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |

[PATCH 6.1.y] driver core: bus: Fix double free in driver API bus_register()

[jianqi.ren.cn]

From: Zijun Hu <quic_zijuhu@quicinc.com>

[ Upstream commit bfa54a793ba77ef696755b66f3ac4ed00c7d1248 ]

For bus_register(), any error which happens after kset_register() will
cause that @priv are freed twice, fixed by setting @priv with NULL after
the first free.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240727-bus_register_fix-v1-1-fed8dd0dba7a@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Using bus->p instead of priv which will be consistent with the context ]
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
---
 drivers/base/bus.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 339a9edcde5f..028e45d2f7fe 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -853,6 +853,8 @@ int bus_register(struct bus_type *bus)
 	bus_remove_file(bus, &bus_attr_uevent);
 bus_uevent_fail:
 	kset_unregister(&bus->p->subsys);
+	/* Above kset_unregister() will kfree @priv */
+	bus->p = NULL;
 out:
 	kfree(bus->p);
 	bus->p = NULL;
-- 
2.25.1

Re: [PATCH 6.1.y] driver core: bus: Fix double free in driver API bus_register()

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: bfa54a793ba77ef696755b66f3ac4ed00c7d1248

WARNING: Author mismatch between patch and upstream commit:
Backport author: <jianqi.ren.cn@windriver.com>
Commit author: Zijun Hu <quic_zijuhu@quicinc.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: d885c464c250)
6.1.y | Present (different SHA1: cb6ae5642a3b)

Note: The patch differs from the upstream commit:
---
1:  bfa54a793ba77 < -:  ------------- driver core: bus: Fix double free in driver API bus_register()
-:  ------------- > 1:  554a31ffcf40a driver core: bus: Fix double free in driver API bus_register()
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |