btrfs-progs: utils: Fix NULL pointer derefernces in string_is_numerical

In get_running_kernel_version() function, we directly pass return
pointer from strtok_r() to string_is_numerical().

Return pointer from strok_r() can be NULL, but string_is_numerical()
can't handle it and will cause NULL pointer derefernces.

Fix it by check if it's a NULL pointer first.

Resolves-Coverity-CID: 1374097
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2016-10-24 10:43:34 +08:00 committed by David Sterba
parent 04329d1e77
commit d6ab2fdca4

View File

@ -4056,6 +4056,8 @@ unsigned int get_unit_mode_from_arg(int *argc, char *argv[], int df_mode)
int string_is_numerical(const char *str)
{
if (!str)
return 0;
if (!(*str >= '0' && *str <= '9'))
return 0;
while (*str >= '0' && *str <= '9')