From: Jan Kara <jack@suse.cz>
Date: Wed, 16 Dec 2020 10:18:43 +0000 (+0100)
Subject: ext4: fix superblock checksum failure when setting password salt
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=dfd56c2c0c0dbb11be939b804ddc8d5395ab3432;p=linux.git

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 f0381876a7e5b..106bf149e8ca8 100644
--- 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: