2018-10-30 22:01:03

by Vasily Averin

Subject: [PATCH v2 09/11] ext4: iloc.bh cleanup in add_new_gdb()

iloc.bh was taken in ext4_reserve_inode_write() and released
in ext4_mark_iloc_dirty(). It should not be released 2nd time
in rollback after failed ext4_handle_dirty_metadata(gdb_bh)

Fixes b40971426a83 ("ext4: add error checking to calls to ...") # 2.6.38

Signed-off-by: Vasily Averin <[email protected]>
---
fs/ext4/resize.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 85158e9de7c2..aedfd6a6fcd1 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -871,7 +871,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
if (unlikely(err)) {
ext4_std_error(sb, err);
- goto exit_inode;
+ goto exit_kfree;
}
brelse(dind);

@@ -891,8 +891,9 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
return err;

exit_inode:
- kvfree(n_group_desc);
brelse(iloc.bh);
+exit_kfree:
+ kvfree(n_group_desc);
exit_dind:
brelse(dind);
exit_bh:
--
2.17.1

2018-11-06 22:21:06

by Theodore Ts'o

Subject: Re: [PATCH v2 09/11] ext4: iloc.bh cleanup in add_new_gdb()

On Wed, Oct 31, 2018 at 12:58:38AM +0300, Vasily Averin wrote:
> iloc.bh was taken in ext4_reserve_inode_write() and released
> in ext4_mark_iloc_dirty(). It should not be released 2nd time
> in rollback after failed ext4_handle_dirty_metadata(gdb_bh)
>
> Fixes b40971426a83 ("ext4: add error checking to calls to ...") # 2.6.38
>
> Signed-off-by: Vasily Averin <[email protected]>

I fixed this in a simpler way:

From 6a91a2eb1c5af1381caebfb4c1c91dc175351f6f Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <[email protected]>
Date: Tue, 6 Nov 2018 17:18:17 -0500
Subject: [PATCH] ext4: avoid possible double brelse() in add_new_gdb() on
error path

Fixes: b40971426a83 ("ext4: add error checking to calls to ...")
Reported-by: Vasily Averin <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected] # 2.6.38
---
fs/ext4/resize.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 85158e9de7c2..a5efee34415f 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -871,6 +871,7 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
if (unlikely(err)) {
ext4_std_error(sb, err);
+ iloc.bh = NULL;
goto exit_inode;
}
brelse(dind);
--
2.18.0.rc0