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 2016f5a5d3cf16e31eae42e841770655bb21a044..75fff707beb6a63153f14678fe1d7b5eb6601b7c 100644 (file)
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -799,7 +799,10 @@ 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: