libsupport: avoid possible null dereference in quota_set_sb_inum()

If the quota type is invalid, quota_sb_inump will return NULL; this
should not cause the program to crash.

Link: https://lore.kernel.org/r/ee0b034c-71f3-63b7-a8de-d8e7760b9545@huawei.com
Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/support/mkquota.c b/lib/support/mkquota.c
index 5de7c48..c89f895 100644 (file)
--- a/lib/support/mkquota.c
+++ b/lib/support/mkquota.c
@@ -99,6 +99,8 @@ void quota_set_sb_inum(ext2_filsys fs, ext2_ino_t ino, enum quota_type qtype)
 
        log_debug("setting quota ino in superblock: ino=%u, type=%d", ino,
                 qtype);
+       if (inump == NULL)
+               return;
        *inump = ino;
        ext2fs_mark_super_dirty(fs);
 }