[PATCH 5.16 118/126] ext4: fix error handling in ext4_fc_record_modified_inode()

Greg Kroah-Hartman
2022-02-07T12:03:26Z

From: Ritesh Harjani <riteshh@linux.ibm.com>

commit cdce59a1549190b66f8e3fe465c2b2f714b98a94 upstream.

Current code does not fully takes care of krealloc() error case, which
could lead to silent memory corruption or a kernel bug. This patch
fixes that.

Also it cleans up some duplicated error handling logic from various
functions in fast_commit.c file.

Reported-by: luo penghao <luo.penghao@zte.com.cn>
Suggested-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/62e8b6a1cce9359682051deb736a3c0953c9d1e9.1642416995.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ext4/fast_commit.c | 64 ++++++++++++++++++++++----------------------------
1 file changed, 29 insertions(+), 35 deletions(-)

--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1435,14 +1435,15 @@ static int ext4_fc_record_modified_inode
if (state->fc_modified_inodes[i] == ino)
return 0;
if (state->fc_modified_inodes_used == state->fc_modified_inodes_size) {
- state->fc_modified_inodes_size +=
- EXT4_FC_REPLAY_REALLOC_INCREMENT;
state->fc_modified_inodes = krealloc(
- state->fc_modified_inodes, sizeof(int) *
- state->fc_modified_inodes_size,
- GFP_KERNEL);
+ state->fc_modified_inodes,
+ sizeof(int) * (state->fc_modified_inodes_size +
+ EXT4_FC_REPLAY_REALLOC_INCREMENT),
+ GFP_KERNEL);
if (!state->fc_modified_inodes)
return -ENOMEM;
+ state->fc_modified_inodes_size +=
+ EXT4_FC_REPLAY_REALLOC_INCREMENT;
}
state->fc_modified_inodes[state->fc_modified_inodes_used++] = ino;
return 0;
@@ -1474,7 +1475,9 @@ static int ext4_fc_replay_inode(struct s
}
inode = NULL;

- ext4_fc_record_modified_inode(sb, ino);
+ ret = ext4_fc_record_modified_inode(sb, ino);
+ if (ret)
+ goto out;

raw_fc_inode = (struct ext4_inode *)
(val + offsetof(struct ext4_fc_inode, fc_raw_inode));
@@ -1674,6 +1677,8 @@ static int ext4_fc_replay_add_range(stru
}

ret = ext4_fc_record_modified_inode(sb, inode->i_ino);
+ if (ret)
+ goto out;

start = le32_to_cpu(ex->ee_block);
start_pblk = ext4_ext_pblock(ex);
@@ -1691,18 +1696,14 @@ static int ext4_fc_replay_add_range(stru
map.m_pblk = 0;
ret = ext4_map_blocks(NULL, inode, &map, 0);

- if (ret < 0) {
- iput(inode);
- return 0;
- }
+ if (ret < 0)
+ goto out;

if (ret == 0) {
/* Range is not mapped */
path = ext4_find_extent(inode, cur, NULL, 0);
- if (IS_ERR(path)) {
- iput(inode);
- return 0;
- }
+ if (IS_ERR(path))
+ goto out;
memset(&newex, 0, sizeof(newex));
newex.ee_block = cpu_to_le32(cur);
ext4_ext_store_pblock(
@@ -1716,10 +1717,8 @@ static int ext4_fc_replay_add_range(stru
up_write((&EXT4_I(inode)->i_data_sem));
ext4_ext_drop_refs(path);
kfree(path);
- if (ret) {
- iput(inode);
- return 0;
- }
+ if (ret)
+ goto out;
goto next;
}

@@ -1732,10 +1731,8 @@ static int ext4_fc_replay_add_range(stru
ret = ext4_ext_replay_update_ex(inode, cur, map.m_len,
ext4_ext_is_unwritten(ex),
start_pblk + cur - start);
- if (ret) {
- iput(inode);
- return 0;
- }
+ if (ret)
+ goto out;
/*
* Mark the old blocks as free since they aren't used
* anymore. We maintain an array of all the modified
@@ -1755,10 +1752,8 @@ static int ext4_fc_replay_add_range(stru
ext4_ext_is_unwritten(ex), map.m_pblk);
ret = ext4_ext_replay_update_ex(inode, cur, map.m_len,
ext4_ext_is_unwritten(ex), map.m_pblk);
- if (ret) {
- iput(inode);
- return 0;
- }
+ if (ret)
+ goto out;
/*
* We may have split the extent tree while toggling the state.
* Try to shrink the extent tree now.
@@ -1770,6 +1765,7 @@ next:
}
ext4_ext_replay_shrink_inode(inode, i_size_read(inode) >>
sb->s_blocksize_bits);
+out:
iput(inode);
return 0;
}
@@ -1799,6 +1795,8 @@ ext4_fc_replay_del_range(struct super_bl
}

ret = ext4_fc_record_modified_inode(sb, inode->i_ino);
+ if (ret)
+ goto out;

jbd_debug(1, "DEL_RANGE, inode %ld, lblk %d, len %d\n",
inode->i_ino, le32_to_cpu(lrange.fc_lblk),
@@ -1808,10 +1806,8 @@ ext4_fc_replay_del_range(struct super_bl
map.m_len = remaining;

ret = ext4_map_blocks(NULL, inode, &map, 0);
- if (ret < 0) {
- iput(inode);
- return 0;
- }
+ if (ret < 0)
+ goto out;
if (ret > 0) {
remaining -= ret;
cur += ret;
@@ -1826,15 +1822,13 @@ ext4_fc_replay_del_range(struct super_bl
ret = ext4_ext_remove_space(inode, lrange.fc_lblk,
lrange.fc_lblk + lrange.fc_len - 1);
up_write(&EXT4_I(inode)->i_data_sem);
- if (ret) {
- iput(inode);
- return 0;
- }
+ if (ret)
+ goto out;
ext4_ext_replay_shrink_inode(inode,
i_size_read(inode) >> sb->s_blocksize_bits);
ext4_mark_inode_dirty(NULL, inode);
+out:
iput(inode);
-
return 0;
}