ext4: fix superblock checksum failure when setting password salt

commit dfd56c2c0c0dbb11be939b804ddc8d5395ab3432 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 9dbb5542167a2b595c75c407d27382b2f1922b6c..6718c7ccd63146991f29963fbac1a35d869a52ae 100644 (file)
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1032,7 +1032,10 @@ 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: