diff options
| author | Peng Fan <peng.fan@nxp.com> | 2020-03-13 09:58:07 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-31 18:37:49 +0200 |
| commit | 9989c022a11fd91f432d1311e5c2e7958c03d68f (patch) | |
| tree | c973dcce5dd872812a4eb13d699d67ea2ae0633b | |
| parent | ddb5bba46338d01565e5052e77607fde0893deee (diff) | |
regmap: debugfs: check count when read regmap file
commit 74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/base/regmap/regmap-debugfs.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index 056e34ce1edd..182b1908edec 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -209,6 +209,9 @@ 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; @@ -357,6 +360,9 @@ 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; |