This is a note to let you know that I've just added the patch titled
of: Don't allow __of_attached_node_sysfs() without CONFIG_SYSFS
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:
of-don-t-allow-__of_attached_node_sysfs-without-conf.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 7039e066e9b8314aac06ed2af512854d2d09324f
Author: Marc Zyngier <maz@xxxxxxxxxx>
Date: Fri Aug 20 15:47:22 2021 +0100
of: Don't allow __of_attached_node_sysfs() without CONFIG_SYSFS
[ Upstream commit 6211e9cb2f8faf7faae0b6caf844bfe9527cc607 ]
Trying to boot without SYSFS, but with OF_DYNAMIC quickly
results in a crash:
[ 0.088460] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
[...]
[ 0.103927] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.14.0-rc3 #4179
[ 0.105810] Hardware name: linux,dummy-virt (DT)
[ 0.107147] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
[ 0.108876] pc : kernfs_find_and_get_ns+0x3c/0x7c
[ 0.110244] lr : kernfs_find_and_get_ns+0x3c/0x7c
[...]
[ 0.134087] Call trace:
[ 0.134800] kernfs_find_and_get_ns+0x3c/0x7c
[ 0.136054] safe_name+0x4c/0xd0
[ 0.136994] __of_attach_node_sysfs+0xf8/0x124
[ 0.138287] of_core_init+0x90/0xfc
[ 0.139296] driver_init+0x30/0x4c
[ 0.140283] kernel_init_freeable+0x160/0x1b8
[ 0.141543] kernel_init+0x30/0x140
[ 0.142561] ret_from_fork+0x10/0x18
While not having sysfs isn't a very common option these days,
it is still expected that such configuration would work.
Paper over it by bailing out from __of_attach_node_sysfs() if
CONFIG_SYSFS isn't enabled.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210820144722.169226-1-maz@xxxxxxxxxx
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/of/kobj.c b/drivers/of/kobj.c
index a32e60b024b8..6675b5e56960 100644
--- a/drivers/of/kobj.c
+++ b/drivers/of/kobj.c
@@ -119,7 +119,7 @@ int __of_attach_node_sysfs(struct device_node *np)
struct property *pp;
int rc;
- if (!of_kset)
+ if (!IS_ENABLED(CONFIG_SYSFS) || !of_kset)
return 0;
np->kobj.kset = of_kset;
