ext4: fix superblock checksum failure when setting password salt

When setting password salt in the superblock, we forget to recompute the
superblock checksum so it will not match until the next superblock
modification which recomputes the checksum. Fix it.

CC: Michael Halcrow <mhalcrow@google.com>
Reported-by: Andreas Dilger <adilger@dilger.ca>
Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20201216101844.22917-8-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index f0381876a7e5b06d288b9d8953bfd2aa69dd3e25..106bf149e8ca8cb01315f1dcc8558368c8fd3590 100644 (file)
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1157,7 +1157,10 @@ resizefs_out:
                        err = ext4_journal_get_write_access(handle, sbi->s_sbh);
                        if (err)
                                goto pwsalt_err_journal;
+                       lock_buffer(sbi->s_sbh);
                        generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
+                       ext4_superblock_csum_set(sb);
+                       unlock_buffer(sbi->s_sbh);
                        err = ext4_handle_dirty_metadata(handle, NULL,
                                                         sbi->s_sbh);
                pwsalt_err_journal: