diff mbox series

[v2,11/16] device-mapper: "." and ".." are not valid symlink names

Message ID 20230530203116.2008-12-demi@invisiblethingslab.com (mailing list archive)
State Superseded, archived
Delegated to: Mike Snitzer
Headers show
Series Diskseq support in loop, device-mapper, and blkback | expand

Commit Message

Demi Marie Obenour May 30, 2023, 8:31 p.m. UTC 
Using either of these is going to greatly confuse userspace, as they are
not valid symlink names and so creating the usual /dev/mapper/NAME
symlink will not be possible.  As creating a device with either of these
names is almost certainly a userspace bug, just error out.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
---
 drivers/md/dm-ioctl.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 9ae00e3c1a72c19575814cf473774835b364320b..17ece816d490b6c40d019da131ade44c9a201dab 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -775,8 +775,10 @@  static int check_name(const char *name)
 		return -EINVAL;
 	}
 
-	if (strcmp(name, DM_CONTROL_NODE) == 0) {
-		DMERR("device name cannot be \"%s\"", DM_CONTROL_NODE);
+	if (strcmp(name, DM_CONTROL_NODE) == 0 ||
+	    strcmp(name, ".") == 0 ||
+	    strcmp(name, "..") == 0) {
+		DMERR("device name cannot be \"%s\", \".\", or \"..\"", DM_CONTROL_NODE);
 		return -EINVAL;
 	}