From: Jan Kara jack@suse.cz
mainline inclusion from mainline-v5.11-rc4 commit 05c2c00f3769abb9e323fcaca70d2de0b48af7ba category: bugfix bugzilla: 46758 CVE: NA
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Protect all superblock modifications (including checksum computation) with a superblock buffer lock. That way we are sure computed checksum matches current superblock contents (a mismatch could cause checksum failures in nojournal mode or if an unjournalled superblock update races with a journalled one). Also we avoid modifying superblock contents while it is being written out (which can cause DIF/DIX failures if we are running in nojournal mode).
Signed-off-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20201216101844.22917-4-jack@suse.cz Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Ye Bin yebin10@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/ext4/ext4_jbd2.c | 1 - fs/ext4/file.c | 3 +++ fs/ext4/inode.c | 3 +++ fs/ext4/namei.c | 6 ++++++ fs/ext4/resize.c | 12 ++++++++++++ fs/ext4/super.c | 2 +- fs/ext4/xattr.c | 3 +++ 7 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c index af2808995858..f720d8ceeff4 100644 --- a/fs/ext4/ext4_jbd2.c +++ b/fs/ext4/ext4_jbd2.c @@ -359,7 +359,6 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line, struct buffer_head *bh = EXT4_SB(sb)->s_sbh; int err = 0;
- ext4_superblock_csum_set(sb); if (ext4_handle_valid(handle)) { err = jbd2_journal_dirty_metadata(handle, bh); if (err) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 52d155b4e733..76dadab4638d 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -432,8 +432,11 @@ static int ext4_sample_last_mounted(struct super_block *sb, err = ext4_journal_get_write_access(handle, sbi->s_sbh); if (err) goto out_journal; + lock_buffer(sbi->s_sbh); strlcpy(sbi->s_es->s_last_mounted, cp, sizeof(sbi->s_es->s_last_mounted)); + ext4_superblock_csum_set(sb); + unlock_buffer(sbi->s_sbh); ext4_handle_dirty_super(handle, sb); out_journal: ext4_journal_stop(handle); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index e8190bec96f0..00dca30cc091 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5403,7 +5403,10 @@ static int ext4_do_update_inode(handle_t *handle, err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); if (err) goto out_brelse; + lock_buffer(EXT4_SB(sb)->s_sbh); ext4_set_feature_large_file(sb); + ext4_superblock_csum_set(sb); + unlock_buffer(EXT4_SB(sb)->s_sbh); ext4_handle_sync(handle); err = ext4_handle_dirty_super(handle, sb); } diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 29e3f7548707..bd5d0e5974d2 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2860,7 +2860,10 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) (le32_to_cpu(sbi->s_es->s_inodes_count))) { /* Insert this inode at the head of the on-disk orphan list */ NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); + lock_buffer(sbi->s_sbh); sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); + ext4_superblock_csum_set(sb); + unlock_buffer(sbi->s_sbh); dirty = true; } list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); @@ -2943,7 +2946,10 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) mutex_unlock(&sbi->s_orphan_lock); goto out_brelse; } + lock_buffer(sbi->s_sbh); sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); + ext4_superblock_csum_set(inode->i_sb); + unlock_buffer(sbi->s_sbh); mutex_unlock(&sbi->s_orphan_lock); err = ext4_handle_dirty_super(handle, inode->i_sb); } else { diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 6a0c5c880354..48c71de2e461 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -900,7 +900,10 @@ static int add_new_gdb(handle_t *handle, struct inode *inode, EXT4_SB(sb)->s_gdb_count++; ext4_kvfree_array_rcu(o_group_desc);
+ lock_buffer(EXT4_SB(sb)->s_sbh); le16_add_cpu(&es->s_reserved_gdt_blocks, -1); + ext4_superblock_csum_set(sb); + unlock_buffer(EXT4_SB(sb)->s_sbh); err = ext4_handle_dirty_super(handle, sb); if (err) ext4_std_error(sb, err); @@ -1386,6 +1389,7 @@ static void ext4_update_super(struct super_block *sb, reserved_blocks *= blocks_count; do_div(reserved_blocks, 100);
+ lock_buffer(sbi->s_sbh); ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * @@ -1423,6 +1427,8 @@ static void ext4_update_super(struct super_block *sb, * active. */ ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + reserved_blocks); + ext4_superblock_csum_set(sb); + unlock_buffer(sbi->s_sbh);
/* Update the free space counts */ percpu_counter_add(&sbi->s_freeclusters_counter, @@ -1719,8 +1725,11 @@ static int ext4_group_extend_no_check(struct super_block *sb, goto errout; }
+ lock_buffer(EXT4_SB(sb)->s_sbh); ext4_blocks_count_set(es, o_blocks_count + add); ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); + ext4_superblock_csum_set(sb); + unlock_buffer(EXT4_SB(sb)->s_sbh); ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, o_blocks_count + add); /* We add the blocks to the bitmap and set the group need init bit */ @@ -1878,10 +1887,13 @@ static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) if (err) goto errout;
+ lock_buffer(sbi->s_sbh); ext4_clear_feature_resize_inode(sb); ext4_set_feature_meta_bg(sb); sbi->s_es->s_first_meta_bg = cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count)); + ext4_superblock_csum_set(sb); + unlock_buffer(sbi->s_sbh);
err = ext4_handle_dirty_super(handle, sb); if (err) { diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 371ba6dda9de..8859803da166 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5033,6 +5033,7 @@ static int ext4_commit_super(struct super_block *sb) if (!sbh || block_device_ejected(sb)) return error;
+ lock_buffer(sbh); /* * If the file system is mounted read-only, don't update the * superblock write time. This avoids updating the superblock @@ -5104,7 +5105,6 @@ static int ext4_commit_super(struct super_block *sb)
BUFFER_TRACE(sbh, "marking dirty"); ext4_superblock_csum_set(sb); - lock_buffer(sbh); if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) { /* * Oh, dear. A previous attempt to write the diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 1a8416f52231..4c2d1afd005f 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -790,7 +790,10 @@ static void ext4_xattr_update_super_block(handle_t *handle,
BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { + lock_buffer(EXT4_SB(sb)->s_sbh); ext4_set_feature_xattr(sb); + ext4_superblock_csum_set(sb); + unlock_buffer(EXT4_SB(sb)->s_sbh); ext4_handle_dirty_super(handle, sb); } }