2007-08-13 09:09:20

by Dmitry Monakhov

Subject: [PATCH] ext3: fix ext34_fill_super group description initialization

->s_group_desc have to be zero filled because if sb_read() failed
we jump to following error path.
failed_mount2:
for (i = 0; i < db_count; i++)
brelse(sbi->s_group_desc[i]);<< Bad things may happen here

Signed-off-by: Dmitry Monakhov <[email protected]>
---
fs/ext3/super.c | 2 +-
fs/ext4/super.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index f8ac18f..208738e 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -1718,7 +1718,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
/ EXT3_BLOCKS_PER_GROUP(sb)) + 1;
db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
EXT3_DESC_PER_BLOCK(sb);
- sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
+ sbi->s_group_desc = kzalloc(db_count * sizeof (struct buffer_head *),
GFP_KERNEL);
if (sbi->s_group_desc == NULL) {
printk (KERN_ERR "EXT3-fs: not enough memory\n");
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 8f1d2f6..fefffc0 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1830,7 +1830,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
sbi->s_groups_count = blocks_count;
db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
EXT4_DESC_PER_BLOCK(sb);
- sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
+ sbi->s_group_desc = kzalloc(db_count * sizeof (struct buffer_head *),
GFP_KERNEL);
if (sbi->s_group_desc == NULL) {
printk (KERN_ERR "EXT4-fs: not enough memory\n");
--
1.5.2.2

2007-08-13 09:24:38

by Dmitri Monakhov

Subject: Re: [PATCH] ext3: fix ext34_fill_super group description initialization

On 13:09 Mon 13 Aug , Dmitry Monakhov wrote:
> ->s_group_desc have to be zero filled because if sb_read() failed
> we jump to following error path.
> failed_mount2:
> for (i = 0; i < db_count; i++)
> brelse(sbi->s_group_desc[i]);<< Bad things may happen here
OOPs i'm sorry. I've lost db_count changing after sb_read() error,
so error path is ok, and this patch is not needed.
>
> Signed-off-by: Dmitry Monakhov <[email protected]>
> ---
> fs/ext3/super.c | 2 +-
> fs/ext4/super.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ext3/super.c b/fs/ext3/super.c
> index f8ac18f..208738e 100644
> --- a/fs/ext3/super.c
> +++ b/fs/ext3/super.c
> @@ -1718,7 +1718,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
> / EXT3_BLOCKS_PER_GROUP(sb)) + 1;
> db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
> EXT3_DESC_PER_BLOCK(sb);
> - sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
> + sbi->s_group_desc = kzalloc(db_count * sizeof (struct buffer_head *),
> GFP_KERNEL);
> if (sbi->s_group_desc == NULL) {
> printk (KERN_ERR "EXT3-fs: not enough memory\n");
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 8f1d2f6..fefffc0 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1830,7 +1830,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
> sbi->s_groups_count = blocks_count;
> db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
> EXT4_DESC_PER_BLOCK(sb);
> - sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
> + sbi->s_group_desc = kzalloc(db_count * sizeof (struct buffer_head *),
> GFP_KERNEL);
> if (sbi->s_group_desc == NULL) {
> printk (KERN_ERR "EXT4-fs: not enough memory\n");
> --
> 1.5.2.2
>
>
> -
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2007-08-13 09:27:45

by Aneesh Kumar K.V

Subject: Re: [PATCH] ext3: fix ext34_fill_super group description initialization

Dmitry Monakhov wrote:
> ->s_group_desc have to be zero filled because if sb_read() failed
> we jump to following error path.
> failed_mount2:
> for (i = 0; i < db_count; i++)
> brelse(sbi->s_group_desc[i]);<< Bad things may happen here
>


But the db_count is updated in the failure path to point to the number
of successful sb_read.

-aneesh

2007-08-13 13:31:02

by Mariusz Kozlowski

Subject: Re: [PATCH] ext3: fix ext34_fill_super group description initialization

> ->s_group_desc have to be zero filled because if sb_read() failed
> we jump to following error path.
> failed_mount2:
> for (i = 0; i < db_count; i++)
> brelse(sbi->s_group_desc[i]);<< Bad things may happen here
>
> Signed-off-by: Dmitry Monakhov <[email protected]>
> ---
> fs/ext3/super.c | 2 +-
> fs/ext4/super.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ext3/super.c b/fs/ext3/super.c
> index f8ac18f..208738e 100644
> --- a/fs/ext3/super.c
> +++ b/fs/ext3/super.c
> @@ -1718,7 +1718,7 @@ static int ext3_fill_super (struct super_block *sb,
> void *data, int silent) / EXT3_BLOCKS_PER_GROUP(sb)) + 1;
> db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
> EXT3_DESC_PER_BLOCK(sb);
> - sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
> + sbi->s_group_desc = kzalloc(db_count * sizeof (struct buffer_head *),
> GFP_KERNEL);

kcalloc?

> if (sbi->s_group_desc == NULL) {
> printk (KERN_ERR "EXT3-fs: not enough memory\n");
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 8f1d2f6..fefffc0 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1830,7 +1830,7 @@ static int ext4_fill_super (struct super_block *sb,
> void *data, int silent) sbi->s_groups_count = blocks_count;
> db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
> EXT4_DESC_PER_BLOCK(sb);
> - sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
> + sbi->s_group_desc = kzalloc(db_count * sizeof (struct buffer_head *),
> GFP_KERNEL);

kcalloc?

> if (sbi->s_group_desc == NULL) {
> printk (KERN_ERR "EXT4-fs: not enough memory\n");

Regards,

Mariusz