From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 14 Jul 2022 09:31:50 +0000 (+0200)
Subject: growfs: ensure that we operate on a block device before issuing a block ioctl
X-Git-Tag: v252-rc1~653^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=12810f3abbc5e3d0d9a54495b79538cb18714180;p=thirdparty%2Fsystemd.git

growfs: ensure that we operate on a block device before issuing a block ioctl

Similar to the previous commit: let's add extra safety so that we don't
issue ioctls on the wrong type of inode.
---

diff --git a/src/partition/growfs.c b/src/partition/growfs.c
index d7069b8d082..cd859468123 100644
--- a/src/partition/growfs.c
+++ b/src/partition/growfs.c
@@ -198,6 +198,7 @@ static int run(int argc, char *argv[]) {
         _cleanup_close_ int mountfd = -1, devfd = -1;
         _cleanup_free_ char *devpath = NULL;
         uint64_t size, newsize;
+        struct stat st;
         dev_t devno;
         int r;
 
@@ -233,10 +234,15 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 return log_error_errno(r, "Failed to format device major/minor path: %m");
 
-        devfd = open(devpath, O_RDONLY|O_CLOEXEC);
+        devfd = open(devpath, O_RDONLY|O_CLOEXEC|O_NOCTTY);
         if (devfd < 0)
                 return log_error_errno(errno, "Failed to open \"%s\": %m", devpath);
 
+        if (fstat(devfd, &st) < 0)
+                return log_error_errno(r, "Failed to stat() device %s: %m", devpath);
+        if (!S_ISBLK(st.st_mode))
+                return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Backing device of file system is not a block device, refusing.");
+
         if (ioctl(devfd, BLKGETSIZE64, &size) != 0)
                 return log_error_errno(errno, "Failed to query size of \"%s\": %m", devpath);