diff mbox

[5/5] resize2fs: sanity check the free blocks and inode counts

Message ID 20170723045035.26019-5-tytso@mit.edu
State Accepted, archived
Headers show

Commit Message

Theodore Ts'o July 23, 2017, 4:50 a.m. UTC
If the free block or free inodes count are larger than the number of
blocks or inodes in the system, request that the file system be
checked.  Otherwise it's possible for calcuate_minimum_resize_size()
to hang in an infinite loop.

This problem was found using American Fuzzy Lop.

Reported-by: Adam Buchbinder <abuchbinder@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
 resize/main.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox

Patch

diff --git a/resize/main.c b/resize/main.c
index 396391b68..ab7375c17 100644
--- a/resize/main.c
+++ b/resize/main.c
@@ -440,6 +440,10 @@  int main (int argc, char ** argv)
 		    !print_min_size)
 			checkit = 1;
 
+		if ((fs->super->s_free_blocks_count > fs->super->s_blocks_count) ||
+		    (fs->super->s_free_inodes_count > fs->super->s_inodes_count))
+			checkit = 1;
+
 		if (checkit) {
 			fprintf(stderr,
 				_("Please run 'e2fsck -f %s' first.\n\n"),