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Message-Id: <20210908024605.16857-1-cymi20@fudan.edu.cn>
Date: Wed, 8 Sep 2021 10:46:05 +0800
From: Chenyuan Mi <cymi20@...an.edu.cn>
To: unlisted-recipients:; (no To-header on input)
Cc: yuanxzhang@...an.edu.cn, Chenyuan Mi <cymi20@...an.edu.cn>,
Xiyu Yang <xiyuyang19@...an.edu.cn>,
Xin Tan <tanxin.ctf@...il.com>,
"Theodore Ts'o" <tytso@....edu>,
Andreas Dilger <adilger.kernel@...ger.ca>,
linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] ext4: Fix refcount leak bug in __ext4_new_inode()
After successfully creating handle by __ext4_journal_start_sb(),
the function forgets to decrease the refcount of handle in several
paths, causing refcount leak.
Fix this issue by recording a flag when successfully getting handle
by __ext4_journal_start_sb(), and decrease the refcount of handle
when exiting this function if holding the flag.
Signed-off-by: Chenyuan Mi <cymi20@...an.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@...an.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@...il.com>
---
fs/ext4/ialloc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index f73e5eb43eae..7563b892c64f 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -944,6 +944,7 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
ext4_group_t flex_group;
struct ext4_group_info *grp = NULL;
bool encrypt = false;
+ bool create_handle = false;
/* Cannot create files in a deleted directory */
if (!dir || !dir->i_nlink)
@@ -1085,6 +1086,7 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
ext4_std_error(sb, err);
goto out;
}
+ create_handle = true;
}
BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
err = ext4_journal_get_write_access(handle, sb, inode_bitmap_bh,
@@ -1345,7 +1347,8 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
ext4_std_error(sb, err);
goto fail_free_drop;
}
-
+ if (create_handle)
+ ext4_journal_stop(handle);
ext4_debug("allocating inode %lu\n", inode->i_ino);
trace_ext4_allocate_inode(inode, dir, mode);
brelse(inode_bitmap_bh);
@@ -1357,6 +1360,8 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
clear_nlink(inode);
unlock_new_inode(inode);
out:
+ if (create_handle)
+ ext4_journal_stop(handle);
dquot_drop(inode);
inode->i_flags |= S_NOQUOTA;
iput(inode);
--
2.17.1
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