Commit e3fc2151 authored by Filipe Manana's avatar Filipe Manana Committed by Greg Kroah-Hartman

Btrfs: ensure path name is null terminated at btrfs_control_ioctl

commit f505754fd6599230371cb01b9332754ddc104be1 upstream.

We were using the path name received from user space without checking that
it is null terminated. While btrfs-progs is well behaved and does proper
validation and null termination, someone could call the ioctl and pass
a non-null terminated patch, leading to buffer overrun problems in the
kernel.  The ioctl is protected by CAP_SYS_ADMIN.

So just set the last byte of the path to a null character, similar to what
we do in other ioctls (add/remove/resize device, snapshot creation, etc).

CC: # 4.4+
Reviewed-by: default avatarAnand Jain <>
Signed-off-by: default avatarFilipe Manana <>
Reviewed-by: default avatarDavid Sterba <>
Signed-off-by: default avatarDavid Sterba <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 327242a4
......@@ -2104,6 +2104,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
vol = memdup_user((void __user *)arg, sizeof(*vol));
if (IS_ERR(vol))
return PTR_ERR(vol);
vol->name[BTRFS_PATH_NAME_MAX] = '\0';
switch (cmd) {
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