redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

regmap: debugfs: check count when read regmap file 

When executing the following command, we met kernel dump.
dmesg -c > /dev/null; cd /sys;
for i in `ls /sys/kernel/debug/regmap/* -d`; do
	echo "Checking regmap in $i";
	cat $i/registers;
done && grep -ri "0x02d0" *;

It is because the count value is too big, and kmalloc fails. So add an
upper bound check to allow max size `PAGE_SIZE << (MAX_ORDER - 1)`.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1584064687-12964-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Joakim cherry pick from upstream commit: 74edd08a4f
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
5.4-rM2-2.2.x-imx-squashed
Peng Fan 2020-03-13 09:58:07 +08:00 committed by Joakim Zhang
parent 55863d4f74
commit f6298e826b
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/base/regmap/regmap-debugfs.c
View File

@ -227,6 +227,9 @@ static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
if (*ppos < 0 || !count)
return -EINVAL;
if (count > (PAGE_SIZE << (MAX_ORDER - 1)))
count = PAGE_SIZE << (MAX_ORDER - 1);
buf = kmalloc(count, GFP_KERNEL);
if (!buf)
return -ENOMEM;
@ -371,6 +374,9 @@ static ssize_t regmap_reg_ranges_read_file(struct file *file,
if (*ppos < 0 || !count)
return -EINVAL;
if (count > (PAGE_SIZE << (MAX_ORDER - 1)))
count = PAGE_SIZE << (MAX_ORDER - 1);
buf = kmalloc(count, GFP_KERNEL);
if (!buf)
return -ENOMEM;