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* [PATCH] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
@ 2021-06-12 14:05 ` Pavel Skripkin
  0 siblings, 0 replies; 4+ messages in thread
From: Pavel Skripkin @ 2021-06-12 14:05 UTC (permalink / raw)
  To: konishi.ryusuke, Vyacheslav.Dubeyko, akpm
  Cc: linux-nilfs, linux-kernel, Pavel Skripkin

My local syzbot instance hit memory leak in nilfs2.
The problem was in missing kobject_put() in
nilfs_sysfs_delete_device_group().

kobject_del() does not call kobject_cleanup() for
passed kobject and it leads to leaking duped
kobject name if kobject_put() was not called.

Fail log:

BUG: memory leak
unreferenced object 0xffff8880596171e0 (size 8):
  comm "syz-executor379", pid 8381, jiffies 4294980258 (age 21.100s)
  hex dump (first 8 bytes):
    6c 6f 6f 70 30 00 00 00                          loop0...
  backtrace:
    [<ffffffff81a2c656>] kstrdup+0x36/0x70 mm/util.c:60
    [<ffffffff81a2c6e3>] kstrdup_const+0x53/0x80 mm/util.c:83
    [<ffffffff83ccc698>] kvasprintf_const+0x108/0x190 lib/kasprintf.c:48
    [<ffffffff83e99926>] kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289
    [<ffffffff83e99fd9>] kobject_add_varg lib/kobject.c:384 [inline]
    [<ffffffff83e99fd9>] kobject_init_and_add+0xc9/0x160 lib/kobject.c:473
    [<ffffffff8304e840>] nilfs_sysfs_create_device_group+0x150/0x800 fs/nilfs2/sysfs.c:999
    [<ffffffff830159f6>] init_nilfs+0xe26/0x12b0 fs/nilfs2/the_nilfs.c:637

Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 fs/nilfs2/sysfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 303d71430bdd..9c6c0e2e5880 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -1053,6 +1053,7 @@ void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
 	nilfs_sysfs_delete_superblock_group(nilfs);
 	nilfs_sysfs_delete_segctor_group(nilfs);
 	kobject_del(&nilfs->ns_dev_kobj);
+	kobject_put(&nilfs->ns_dev_kobj);
 	kfree(nilfs->ns_dev_subgroups);
 }
 
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
@ 2021-06-12 14:05 ` Pavel Skripkin
  0 siblings, 0 replies; 4+ messages in thread
From: Pavel Skripkin @ 2021-06-12 14:05 UTC (permalink / raw)
  To: konishi.ryusuke-Re5JQEeQqe8AvxtiuMwx3w,
	Vyacheslav.Dubeyko-XckBA8eALwE,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b
  Cc: linux-nilfs-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Pavel Skripkin

My local syzbot instance hit memory leak in nilfs2.
The problem was in missing kobject_put() in
nilfs_sysfs_delete_device_group().

kobject_del() does not call kobject_cleanup() for
passed kobject and it leads to leaking duped
kobject name if kobject_put() was not called.

Fail log:

BUG: memory leak
unreferenced object 0xffff8880596171e0 (size 8):
  comm "syz-executor379", pid 8381, jiffies 4294980258 (age 21.100s)
  hex dump (first 8 bytes):
    6c 6f 6f 70 30 00 00 00                          loop0...
  backtrace:
    [<ffffffff81a2c656>] kstrdup+0x36/0x70 mm/util.c:60
    [<ffffffff81a2c6e3>] kstrdup_const+0x53/0x80 mm/util.c:83
    [<ffffffff83ccc698>] kvasprintf_const+0x108/0x190 lib/kasprintf.c:48
    [<ffffffff83e99926>] kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289
    [<ffffffff83e99fd9>] kobject_add_varg lib/kobject.c:384 [inline]
    [<ffffffff83e99fd9>] kobject_init_and_add+0xc9/0x160 lib/kobject.c:473
    [<ffffffff8304e840>] nilfs_sysfs_create_device_group+0x150/0x800 fs/nilfs2/sysfs.c:999
    [<ffffffff830159f6>] init_nilfs+0xe26/0x12b0 fs/nilfs2/the_nilfs.c:637

Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group")
Signed-off-by: Pavel Skripkin <paskripkin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 fs/nilfs2/sysfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 303d71430bdd..9c6c0e2e5880 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -1053,6 +1053,7 @@ void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
 	nilfs_sysfs_delete_superblock_group(nilfs);
 	nilfs_sysfs_delete_segctor_group(nilfs);
 	kobject_del(&nilfs->ns_dev_kobj);
+	kobject_put(&nilfs->ns_dev_kobj);
 	kfree(nilfs->ns_dev_subgroups);
 }
 
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
@ 2021-06-24 19:29   ` Ryusuke Konishi
  0 siblings, 0 replies; 4+ messages in thread
From: Ryusuke Konishi @ 2021-06-24 19:29 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Pavel Skripkin, Vyacheslav Dubeyko, linux-nilfs, LKML

Hi Andrew,

On Sat, Jun 12, 2021 at 11:06 PM Pavel Skripkin <paskripkin@gmail.com> wrote:
>
> My local syzbot instance hit memory leak in nilfs2.
> The problem was in missing kobject_put() in
> nilfs_sysfs_delete_device_group().
>
> kobject_del() does not call kobject_cleanup() for
> passed kobject and it leads to leaking duped
> kobject name if kobject_put() was not called.
>
> Fail log:
>
> BUG: memory leak
> unreferenced object 0xffff8880596171e0 (size 8):
>   comm "syz-executor379", pid 8381, jiffies 4294980258 (age 21.100s)
>   hex dump (first 8 bytes):
>     6c 6f 6f 70 30 00 00 00                          loop0...
>   backtrace:
>     [<ffffffff81a2c656>] kstrdup+0x36/0x70 mm/util.c:60
>     [<ffffffff81a2c6e3>] kstrdup_const+0x53/0x80 mm/util.c:83
>     [<ffffffff83ccc698>] kvasprintf_const+0x108/0x190 lib/kasprintf.c:48
>     [<ffffffff83e99926>] kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289
>     [<ffffffff83e99fd9>] kobject_add_varg lib/kobject.c:384 [inline]
>     [<ffffffff83e99fd9>] kobject_init_and_add+0xc9/0x160 lib/kobject.c:473
>     [<ffffffff8304e840>] nilfs_sysfs_create_device_group+0x150/0x800 fs/nilfs2/sysfs.c:999
>     [<ffffffff830159f6>] init_nilfs+0xe26/0x12b0 fs/nilfs2/the_nilfs.c:637
>
> Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group")
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>

This fix looks correct to me.

Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>

Thanks,
Ryusuke Konishi

> ---
>  fs/nilfs2/sysfs.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
> index 303d71430bdd..9c6c0e2e5880 100644
> --- a/fs/nilfs2/sysfs.c
> +++ b/fs/nilfs2/sysfs.c
> @@ -1053,6 +1053,7 @@ void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
>         nilfs_sysfs_delete_superblock_group(nilfs);
>         nilfs_sysfs_delete_segctor_group(nilfs);
>         kobject_del(&nilfs->ns_dev_kobj);
> +       kobject_put(&nilfs->ns_dev_kobj);
>         kfree(nilfs->ns_dev_subgroups);
>  }
>
> --
> 2.32.0
>

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
@ 2021-06-24 19:29   ` Ryusuke Konishi
  0 siblings, 0 replies; 4+ messages in thread
From: Ryusuke Konishi @ 2021-06-24 19:29 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Pavel Skripkin, Vyacheslav Dubeyko, linux-nilfs, LKML

Hi Andrew,

On Sat, Jun 12, 2021 at 11:06 PM Pavel Skripkin <paskripkin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
> My local syzbot instance hit memory leak in nilfs2.
> The problem was in missing kobject_put() in
> nilfs_sysfs_delete_device_group().
>
> kobject_del() does not call kobject_cleanup() for
> passed kobject and it leads to leaking duped
> kobject name if kobject_put() was not called.
>
> Fail log:
>
> BUG: memory leak
> unreferenced object 0xffff8880596171e0 (size 8):
>   comm "syz-executor379", pid 8381, jiffies 4294980258 (age 21.100s)
>   hex dump (first 8 bytes):
>     6c 6f 6f 70 30 00 00 00                          loop0...
>   backtrace:
>     [<ffffffff81a2c656>] kstrdup+0x36/0x70 mm/util.c:60
>     [<ffffffff81a2c6e3>] kstrdup_const+0x53/0x80 mm/util.c:83
>     [<ffffffff83ccc698>] kvasprintf_const+0x108/0x190 lib/kasprintf.c:48
>     [<ffffffff83e99926>] kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289
>     [<ffffffff83e99fd9>] kobject_add_varg lib/kobject.c:384 [inline]
>     [<ffffffff83e99fd9>] kobject_init_and_add+0xc9/0x160 lib/kobject.c:473
>     [<ffffffff8304e840>] nilfs_sysfs_create_device_group+0x150/0x800 fs/nilfs2/sysfs.c:999
>     [<ffffffff830159f6>] init_nilfs+0xe26/0x12b0 fs/nilfs2/the_nilfs.c:637
>
> Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group")
> Signed-off-by: Pavel Skripkin <paskripkin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

This fix looks correct to me.

Acked-by: Ryusuke Konishi <konishi.ryusuke-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

Thanks,
Ryusuke Konishi

> ---
>  fs/nilfs2/sysfs.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
> index 303d71430bdd..9c6c0e2e5880 100644
> --- a/fs/nilfs2/sysfs.c
> +++ b/fs/nilfs2/sysfs.c
> @@ -1053,6 +1053,7 @@ void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
>         nilfs_sysfs_delete_superblock_group(nilfs);
>         nilfs_sysfs_delete_segctor_group(nilfs);
>         kobject_del(&nilfs->ns_dev_kobj);
> +       kobject_put(&nilfs->ns_dev_kobj);
>         kfree(nilfs->ns_dev_subgroups);
>  }
>
> --
> 2.32.0
>

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-06-24 19:29 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-12 14:05 [PATCH] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group Pavel Skripkin
2021-06-12 14:05 ` Pavel Skripkin
2021-06-24 19:29 ` Ryusuke Konishi
2021-06-24 19:29   ` Ryusuke Konishi

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