| Message ID | 1494349025-6561-6-git-send-email-bmarzins@redhat.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | christophe varoqui |
| Headers | show |
On Tue, 2017-05-09 at 11:57 -0500, Benjamin Marzinski wrote: > There are a number of issues in the the kpartx device checking code. > First, it accepts files that are neither regular files or a block > device > nodes (you can run kpartx on character devices or directories, and it > will treat them as block devices). When trying to figure out the > basename of a device, the code returns garbage if the path doesn't > include a '/'. Finally, the set_delimiter code can access memory > outside > of the string if an empty string is passed in. > > Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Reviewed-by: Martin Wilck <mwilck@suse.com>
diff --git a/kpartx/kpartx.c b/kpartx/kpartx.c index cc7e2e7..a1af156 100644 --- a/kpartx/kpartx.c +++ b/kpartx/kpartx.c @@ -135,10 +135,13 @@ set_delimiter (char * device, char * delimiter) { char * p = device; - while (*(p++) != 0x0) + if (*p == 0x0) + return; + + while (*(++p) != 0x0) continue; - if (isdigit(*(p - 2))) + if (isdigit(*(p - 1))) *delimiter = 'p'; } @@ -157,15 +160,17 @@ strip_slash (char * device) static int find_devname_offset (char * device) { - char *p, *q = NULL; + char *p, *q; - p = device; + q = p = device; - while (*p++) + while (*p) { if (*p == '/') - q = p; + q = p + 1; + p++; + } - return (int)(q - device) + 1; + return (int)(q - device); } static char * @@ -381,6 +386,10 @@ main(int argc, char **argv){ exit (1); } } + else if (!S_ISBLK(buf.st_mode)) { + fprintf(stderr, "invalid device: %s\n", device); + exit(1); + } off = find_devname_offset(device);
There are a number of issues in the the kpartx device checking code. First, it accepts files that are neither regular files or a block device nodes (you can run kpartx on character devices or directories, and it will treat them as block devices). When trying to figure out the basename of a device, the code returns garbage if the path doesn't include a '/'. Finally, the set_delimiter code can access memory outside of the string if an empty string is passed in. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> --- kpartx/kpartx.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-)