Linux-ARM-Kernel Archive on
 help / color / Atom feed
Subject: [PATCH V2 1/2] soc: imx8: Fix potential kernel dump in error path
Date: Fri, 14 Jun 2019 16:07:47 +0800
Message-ID: <> (raw)

From: Anson Huang <>

When SoC's revision value is 0, SoC driver will print out
"unknown" in sysfs's revision node, this "unknown" is a
static string which can NOT be freed, this will caused below
kernel dump in later error path which calls kfree:

kernel BUG at mm/slub.c:3942!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc4-next-20190611-00023-g705146c-dirty #2197
Hardware name: NXP i.MX8MQ EVK (DT)
pstate: 60000005 (nZCv daif -PAN -UAO)
pc : kfree+0x170/0x1b0
lr : imx8_soc_init+0xc0/0xe4
sp : ffff00001003bd10
x29: ffff00001003bd10 x28: ffff00001121e0a0
x27: ffff000011482000 x26: ffff00001117068c
x25: ffff00001121e100 x24: ffff000011482000
x23: ffff000010fe2b58 x22: ffff0000111b9ab0
x21: ffff8000bd9dfba0 x20: ffff0000111b9b70
x19: ffff7e000043f880 x18: 0000000000001000
x17: ffff000010d05fa0 x16: ffff0000122e0000
x15: 0140000000000000 x14: 0000000030360000
x13: ffff8000b94b5bb0 x12: 0000000000000038
x11: ffffffffffffffff x10: ffffffffffffffff
x9 : 0000000000000003 x8 : ffff8000b9488147
x7 : ffff00001003bc00 x6 : 0000000000000000
x5 : 0000000000000003 x4 : 0000000000000003
x3 : 0000000000000003 x2 : b8793acd604edf00
x1 : ffff7e000043f880 x0 : ffff7e000043f888
Call trace:

This patch fixes this potential kernel dump when a chip's
revision is "unknown", it is done by checking whether the
revision space can be freed.

Fixes: a7e26f356ca1 ("soc: imx: Add generic i.MX8 SoC driver")
Signed-off-by: Anson Huang <>
Changes since V1:
	- still need the "unknown" info for revision to avoid confusion, so fix this issue
	  by checking whether the revision space can be freed before freeing it.
 drivers/soc/imx/soc-imx8.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c
index 02309a2..5c7f330 100644
--- a/drivers/soc/imx/soc-imx8.c
+++ b/drivers/soc/imx/soc-imx8.c
@@ -155,7 +155,8 @@ static int __init imx8_soc_init(void)
 	return 0;
-	kfree(soc_dev_attr->revision);
+	if (strcmp(soc_dev_attr->revision, "unknown"))
+		kfree(soc_dev_attr->revision);

linux-arm-kernel mailing list

             reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-14  8:07 Anson.Huang [this message]
2019-06-14  8:07 ` [PATCH V2 2/2] soc: imx8: Use existing of_root directly Anson.Huang
2019-06-18  9:14   ` Shawn Guo
2019-06-18  9:44     ` Anson Huang
2019-06-18  9:13 ` [PATCH V2 1/2] soc: imx8: Fix potential kernel dump in error path Shawn Guo

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on

Archives are clonable:
	git clone --mirror linux-arm-kernel/git/0.git
	git clone --mirror linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ \
	public-inbox-index linux-arm-kernel

Newsgroup available over NNTP:

AGPL code for this site: git clone public-inbox