[PATCH AUTOSEL 4.19 097/167] ext4: protect journal inode's blocks using block_validity

[PATCH AUTOSEL 4.19 097/167] ext4: protect journal inode's blocks using block_validity

[Sasha Levin]

From: Theodore Ts'o <tytso@mit.edu>

[ Upstream commit 345c0dbf3a30872d9b204db96b5857cd00808cae ]

Add the blocks which belong to the journal inode to block_validity's
system zone so attempts to deallocate or overwrite the journal due a
corrupted file system where the journal blocks are also claimed by
another inode.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202879
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/block_validity.c | 48 ++++++++++++++++++++++++++++++++++++++++
 fs/ext4/inode.c          |  4 ++++
 2 files changed, 52 insertions(+)

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 913061c0de1b3..9409b1e11a22e 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -137,6 +137,48 @@ static void debug_print_tree(struct ext4_sb_info *sbi)
 	printk(KERN_CONT "\n");
 }
 
+static int ext4_protect_reserved_inode(struct super_block *sb, u32 ino)
+{
+	struct inode *inode;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_map_blocks map;
+	u32 i = 0, err = 0, num, n;
+
+	if ((ino < EXT4_ROOT_INO) ||
+	    (ino > le32_to_cpu(sbi->s_es->s_inodes_count)))
+		return -EINVAL;
+	inode = ext4_iget(sb, ino, EXT4_IGET_SPECIAL);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+	num = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+	while (i < num) {
+		map.m_lblk = i;
+		map.m_len = num - i;
+		n = ext4_map_blocks(NULL, inode, &map, 0);
+		if (n < 0) {
+			err = n;
+			break;
+		}
+		if (n == 0) {
+			i++;
+		} else {
+			if (!ext4_data_block_valid(sbi, map.m_pblk, n)) {
+				ext4_error(sb, "blocks %llu-%llu from inode %u "
+					   "overlap system zone", map.m_pblk,
+					   map.m_pblk + map.m_len - 1, ino);
+				err = -EFSCORRUPTED;
+				break;
+			}
+			err = add_system_zone(sbi, map.m_pblk, n);
+			if (err < 0)
+				break;
+			i += n;
+		}
+	}
+	iput(inode);
+	return err;
+}
+
 int ext4_setup_system_zone(struct super_block *sb)
 {
 	ext4_group_t ngroups = ext4_get_groups_count(sb);
@@ -171,6 +213,12 @@ int ext4_setup_system_zone(struct super_block *sb)
 		if (ret)
 			return ret;
 	}
+	if (ext4_has_feature_journal(sb) && sbi->s_es->s_journal_inum) {
+		ret = ext4_protect_reserved_inode(sb,
+				le32_to_cpu(sbi->s_es->s_journal_inum));
+		if (ret)
+			return ret;
+	}
 
 	if (test_opt(sb, DEBUG))
 		debug_print_tree(sbi);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e65559bf77281..cff6277f7a9ff 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -399,6 +399,10 @@ static int __check_block_validity(struct inode *inode, const char *func,
 				unsigned int line,
 				struct ext4_map_blocks *map)
 {
+	if (ext4_has_feature_journal(inode->i_sb) &&
+	    (inode->i_ino ==
+	     le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum)))
+		return 0;
 	if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
 				   map->m_len)) {
 		ext4_error_inode(inode, func, line, map->m_pblk,
-- 
2.20.1

[PATCH AUTOSEL 4.19 164/167] ext4: don't perform block validity checks on the journal inode

[Sasha Levin]

From: Theodore Ts'o <tytso@mit.edu>

[ Upstream commit 0a944e8a6c66ca04c7afbaa17e22bf208a8b37f0 ]

Since the journal inode is already checked when we added it to the
block validity's system zone, if we check it again, we'll just trigger
a failure.

This was causing failures like this:

[   53.897001] EXT4-fs error (device sda): ext4_find_extent:909: inode
#8: comm jbd2/sda-8: pblk 121667583 bad header/extent: invalid extent entries - magic f30a, entries 8, max 340(340), depth 0(0)
[   53.931430] jbd2_journal_bmap: journal block not found at offset 49 on sda-8
[   53.938480] Aborting journal on device sda-8.

... but only if the system was under enough memory pressure that
logical->physical mapping for the journal inode gets pushed out of the
extent cache.  (This is why it wasn't noticed earlier.)

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Dan Rue <dan.rue@linaro.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 45aea792d22a0..00bf0b67aae87 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -518,10 +518,14 @@ __read_extent_tree_block(const char *function, unsigned int line,
 	}
 	if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
 		return bh;
-	err = __ext4_ext_check(function, line, inode,
-			       ext_block_hdr(bh), depth, pblk);
-	if (err)
-		goto errout;
+	if (!ext4_has_feature_journal(inode->i_sb) ||
+	    (inode->i_ino !=
+	     le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum))) {
+		err = __ext4_ext_check(function, line, inode,
+				       ext_block_hdr(bh), depth, pblk);
+		if (err)
+			goto errout;
+	}
 	set_buffer_verified(bh);
 	/*
 	 * If this is a leaf block, cache all of its entries
-- 
2.20.1

[PATCH AUTOSEL 4.19 165/167] ext4: fix block validity checks for journal inodes using indirect blocks

[Sasha Levin]

From: Theodore Ts'o <tytso@mit.edu>

[ Upstream commit 170417c8c7bb2cbbdd949bf5c443c0c8f24a203b ]

Commit 345c0dbf3a30 ("ext4: protect journal inode's blocks using
block_validity") failed to add an exception for the journal inode in
ext4_check_blockref(), which is the function used by ext4_get_branch()
for indirect blocks.  This caused attempts to read from the ext3-style
journals to fail with:

[  848.968550] EXT4-fs error (device sdb7): ext4_get_branch:171: inode #8: block 30343695: comm jbd2/sdb7-8: invalid block

Fix this by adding the missing exception check.

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/block_validity.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 9409b1e11a22e..cd7129b622f85 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -275,6 +275,11 @@ int ext4_check_blockref(const char *function, unsigned int line,
 	__le32 *bref = p;
 	unsigned int blk;
 
+	if (ext4_has_feature_journal(inode->i_sb) &&
+	    (inode->i_ino ==
+	     le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum)))
+		return 0;
+
 	while (bref < p+max) {
 		blk = le32_to_cpu(*bref++);
 		if (blk &&
-- 
2.20.1

[PATCH AUTOSEL 4.19 166/167] ext4: unsigned int compared against zero

[Sasha Levin]

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit fbbbbd2f28aec991f3fbc248df211550fbdfd58c ]

There are two cases where u32 variables n and err are being checked
for less than zero error values, the checks is always false because
the variables are not signed. Fix this by making the variables ints.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/block_validity.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index cd7129b622f85..e8e27cdc2f677 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -142,7 +142,8 @@ static int ext4_protect_reserved_inode(struct super_block *sb, u32 ino)
 	struct inode *inode;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_map_blocks map;
-	u32 i = 0, err = 0, num, n;
+	u32 i = 0, num;
+	int err = 0, n;
 
 	if ((ino < EXT4_ROOT_INO) ||
 	    (ino > le32_to_cpu(sbi->s_es->s_inodes_count)))
-- 
2.20.1