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| author |   Peng Fan <peng.fan@nxp.com> | 2020-03-13 09:58:07 +0800 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2020-03-13 16:33:58 +0000 |
| commit | 74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91 (patch) | |
| tree | c52fc2420ac61aba892572fff6da666db1713cfb /drivers/base/regmap | |
| parent | Linux 5.6-rc1 (diff) | |
| download | linux-dev-74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91.tar.xz linux-dev-74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91.zip | |
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>
Diffstat (limited to 'drivers/base/regmap')
| -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 e72843fe41df..089e5dc7144a 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -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; |