diff options
| author | Nicholas Johnson | 2020-03-10 13:22:52 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2020-03-19 07:41:03 +0100 |
| commit | 3c91ef69a3e94f78546b246225ed573fbf1735b4 (patch) | |
| tree | 3251acb10ce8c6a59de3426fa5810b002a730114 | |
| parent | 061a320b32d47438d64d64b412c0ea2c323a1470 (diff) | |
nvmem: check for NULL reg_read and reg_write before dereferencing
Return -EPERM if reg_read is NULL in bin_attr_nvmem_read() or if
reg_write is NULL in bin_attr_nvmem_write().
This prevents NULL dereferences such as the one described in
03cd45d2e219 ("thunderbolt: Prevent crash if non-active NVMem file is
read")
Signed-off-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200310132257.23358-10-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/nvmem/nvmem-sysfs.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/nvmem/nvmem-sysfs.c b/drivers/nvmem/nvmem-sysfs.c index 9e0c429cd08a..8759c4470012 100644 --- a/drivers/nvmem/nvmem-sysfs.c +++ b/drivers/nvmem/nvmem-sysfs.c @@ -56,6 +56,9 @@ static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, count = round_down(count, nvmem->word_size); + if (!nvmem->reg_read) + return -EPERM; + rc = nvmem->reg_read(nvmem->priv, pos, buf, count); if (rc) @@ -90,6 +93,9 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, count = round_down(count, nvmem->word_size); + if (!nvmem->reg_write) + return -EPERM; + rc = nvmem->reg_write(nvmem->priv, pos, buf, count); if (rc) |