ext4: fix superblock checksum failure when setting password salt

BugLink: https://bugs.launchpad.net/bugs/1914654
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: William Breathitt Gray <william.gray@canonical.com>

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 0b7f316fd30f41391f9587487dbc41e204d5efae..ba13fbb443d58460aa9a2e1f3579ad9efe9c2427 100644 (file)
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1160,7 +1160,10 @@ 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: