* [PATCH] virtiofs: fix memory leak in virtio_fs_probe()
@ 2021-03-16 17:02 Luis Henriques
2021-03-16 18:17 ` Vivek Goyal
0 siblings, 1 reply; 6+ messages in thread
From: Luis Henriques @ 2021-03-16 17:02 UTC (permalink / raw)
To: Vivek Goyal, Stefan Hajnoczi, Miklos Szeredi
Cc: virtualization, linux-fsdevel, linux-kernel, Luis Henriques, stable
When accidentally passing twice the same tag to qemu, kmemleak ended up
reporting a memory leak in virtiofs. Also, looking at the log I saw the
following error (that's when I realised the duplicated tag):
virtiofs: probe of virtio5 failed with error -17
Here's the kmemleak log for reference:
unreferenced object 0xffff888103d47800 (size 1024):
comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................
backtrace:
[<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
[<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
[<000000004d6baf3c>] really_probe+0xea/0x430
[<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
[<00000000196f47a7>] __driver_attach+0x98/0x140
[<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
[<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
[<0000000032b09ba7>] driver_register+0x8f/0xe0
[<00000000cdd55998>] 0xffffffffa002c013
[<000000000ea196a2>] do_one_initcall+0x64/0x2e0
[<0000000008f727ce>] do_init_module+0x5c/0x260
[<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
[<00000000ad2f48c6>] do_syscall_64+0x33/0x40
[<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae
Cc: stable@vger.kernel.org
Signed-off-by: Luis Henriques <lhenriques@suse.de>
---
fs/fuse/virtio_fs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 8868ac31a3c0..4e6ef9f24e84 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -899,7 +899,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
out:
vdev->priv = NULL;
- kfree(fs);
+ virtio_fs_put(fs);
return ret;
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] virtiofs: fix memory leak in virtio_fs_probe()
2021-03-16 17:02 [PATCH] virtiofs: fix memory leak in virtio_fs_probe() Luis Henriques
2021-03-16 18:17 ` Vivek Goyal
@ 2021-03-16 18:17 ` Vivek Goyal
0 siblings, 0 replies; 6+ messages in thread
From: Vivek Goyal @ 2021-03-16 18:17 UTC (permalink / raw)
To: Luis Henriques
Cc: Stefan Hajnoczi, Miklos Szeredi, virtualization, linux-fsdevel,
linux-kernel, stable, virtio-fs-list
On Tue, Mar 16, 2021 at 05:02:34PM +0000, Luis Henriques wrote:
> When accidentally passing twice the same tag to qemu, kmemleak ended up
> reporting a memory leak in virtiofs. Also, looking at the log I saw the
> following error (that's when I realised the duplicated tag):
>
> virtiofs: probe of virtio5 failed with error -17
>
> Here's the kmemleak log for reference:
>
> unreferenced object 0xffff888103d47800 (size 1024):
> comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
> hex dump (first 32 bytes):
> 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
> ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................
> backtrace:
> [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
> [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
> [<000000004d6baf3c>] really_probe+0xea/0x430
> [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
> [<00000000196f47a7>] __driver_attach+0x98/0x140
> [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
> [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
> [<0000000032b09ba7>] driver_register+0x8f/0xe0
> [<00000000cdd55998>] 0xffffffffa002c013
> [<000000000ea196a2>] do_one_initcall+0x64/0x2e0
> [<0000000008f727ce>] do_init_module+0x5c/0x260
> [<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
> [<00000000ad2f48c6>] do_syscall_64+0x33/0x40
> [<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Luis Henriques <lhenriques@suse.de>
Hi Luis,
Thanks for the report and the fix. So looks like leak is happening
because we are not doing kfree(fs->vqs) in error path.
> ---
> fs/fuse/virtio_fs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
> index 8868ac31a3c0..4e6ef9f24e84 100644
> --- a/fs/fuse/virtio_fs.c
> +++ b/fs/fuse/virtio_fs.c
> @@ -899,7 +899,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
>
> out:
> vdev->priv = NULL;
> - kfree(fs);
> + virtio_fs_put(fs);
[ CC virtio-fs list ]
fs object is not fully formed. So calling virtio_fs_put() is little odd.
I will expect it to be called if somebody takes a reference using _get()
or in the final virtio_fs_remove() when creation reference should go
away.
How about open coding it and free fs->vqs explicitly. Something like
as follows.
@@ -896,7 +896,7 @@ static int virtio_fs_probe(struct virtio
out_vqs:
vdev->config->reset(vdev);
virtio_fs_cleanup_vqs(vdev, fs);
-
+ kfree(fs->vqs);
out:
vdev->priv = NULL;
kfree(fs);
Thanks
Vivek
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] virtiofs: fix memory leak in virtio_fs_probe()
@ 2021-03-16 18:17 ` Vivek Goyal
0 siblings, 0 replies; 6+ messages in thread
From: Vivek Goyal @ 2021-03-16 18:17 UTC (permalink / raw)
To: Luis Henriques
Cc: Miklos Szeredi, linux-kernel, stable, virtualization,
virtio-fs-list, Stefan Hajnoczi, linux-fsdevel
On Tue, Mar 16, 2021 at 05:02:34PM +0000, Luis Henriques wrote:
> When accidentally passing twice the same tag to qemu, kmemleak ended up
> reporting a memory leak in virtiofs. Also, looking at the log I saw the
> following error (that's when I realised the duplicated tag):
>
> virtiofs: probe of virtio5 failed with error -17
>
> Here's the kmemleak log for reference:
>
> unreferenced object 0xffff888103d47800 (size 1024):
> comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
> hex dump (first 32 bytes):
> 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
> ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................
> backtrace:
> [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
> [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
> [<000000004d6baf3c>] really_probe+0xea/0x430
> [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
> [<00000000196f47a7>] __driver_attach+0x98/0x140
> [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
> [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
> [<0000000032b09ba7>] driver_register+0x8f/0xe0
> [<00000000cdd55998>] 0xffffffffa002c013
> [<000000000ea196a2>] do_one_initcall+0x64/0x2e0
> [<0000000008f727ce>] do_init_module+0x5c/0x260
> [<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
> [<00000000ad2f48c6>] do_syscall_64+0x33/0x40
> [<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Luis Henriques <lhenriques@suse.de>
Hi Luis,
Thanks for the report and the fix. So looks like leak is happening
because we are not doing kfree(fs->vqs) in error path.
> ---
> fs/fuse/virtio_fs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
> index 8868ac31a3c0..4e6ef9f24e84 100644
> --- a/fs/fuse/virtio_fs.c
> +++ b/fs/fuse/virtio_fs.c
> @@ -899,7 +899,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
>
> out:
> vdev->priv = NULL;
> - kfree(fs);
> + virtio_fs_put(fs);
[ CC virtio-fs list ]
fs object is not fully formed. So calling virtio_fs_put() is little odd.
I will expect it to be called if somebody takes a reference using _get()
or in the final virtio_fs_remove() when creation reference should go
away.
How about open coding it and free fs->vqs explicitly. Something like
as follows.
@@ -896,7 +896,7 @@ static int virtio_fs_probe(struct virtio
out_vqs:
vdev->config->reset(vdev);
virtio_fs_cleanup_vqs(vdev, fs);
-
+ kfree(fs->vqs);
out:
vdev->priv = NULL;
kfree(fs);
Thanks
Vivek
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Virtio-fs] [PATCH] virtiofs: fix memory leak in virtio_fs_probe()
@ 2021-03-16 18:17 ` Vivek Goyal
0 siblings, 0 replies; 6+ messages in thread
From: Vivek Goyal @ 2021-03-16 18:17 UTC (permalink / raw)
To: Luis Henriques
Cc: Miklos Szeredi, linux-kernel, stable, virtualization,
virtio-fs-list, linux-fsdevel
On Tue, Mar 16, 2021 at 05:02:34PM +0000, Luis Henriques wrote:
> When accidentally passing twice the same tag to qemu, kmemleak ended up
> reporting a memory leak in virtiofs. Also, looking at the log I saw the
> following error (that's when I realised the duplicated tag):
>
> virtiofs: probe of virtio5 failed with error -17
>
> Here's the kmemleak log for reference:
>
> unreferenced object 0xffff888103d47800 (size 1024):
> comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
> hex dump (first 32 bytes):
> 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
> ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................
> backtrace:
> [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
> [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
> [<000000004d6baf3c>] really_probe+0xea/0x430
> [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
> [<00000000196f47a7>] __driver_attach+0x98/0x140
> [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
> [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
> [<0000000032b09ba7>] driver_register+0x8f/0xe0
> [<00000000cdd55998>] 0xffffffffa002c013
> [<000000000ea196a2>] do_one_initcall+0x64/0x2e0
> [<0000000008f727ce>] do_init_module+0x5c/0x260
> [<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
> [<00000000ad2f48c6>] do_syscall_64+0x33/0x40
> [<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Luis Henriques <lhenriques@suse.de>
Hi Luis,
Thanks for the report and the fix. So looks like leak is happening
because we are not doing kfree(fs->vqs) in error path.
> ---
> fs/fuse/virtio_fs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
> index 8868ac31a3c0..4e6ef9f24e84 100644
> --- a/fs/fuse/virtio_fs.c
> +++ b/fs/fuse/virtio_fs.c
> @@ -899,7 +899,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
>
> out:
> vdev->priv = NULL;
> - kfree(fs);
> + virtio_fs_put(fs);
[ CC virtio-fs list ]
fs object is not fully formed. So calling virtio_fs_put() is little odd.
I will expect it to be called if somebody takes a reference using _get()
or in the final virtio_fs_remove() when creation reference should go
away.
How about open coding it and free fs->vqs explicitly. Something like
as follows.
@@ -896,7 +896,7 @@ static int virtio_fs_probe(struct virtio
out_vqs:
vdev->config->reset(vdev);
virtio_fs_cleanup_vqs(vdev, fs);
-
+ kfree(fs->vqs);
out:
vdev->priv = NULL;
kfree(fs);
Thanks
Vivek
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] virtiofs: fix memory leak in virtio_fs_probe()
2021-03-16 18:17 ` Vivek Goyal
@ 2021-03-16 21:14 ` Luis Henriques
-1 siblings, 0 replies; 6+ messages in thread
From: Luis Henriques @ 2021-03-16 21:14 UTC (permalink / raw)
To: Vivek Goyal
Cc: Stefan Hajnoczi, Miklos Szeredi, virtualization, linux-fsdevel,
linux-kernel, stable, virtio-fs-list
Vivek Goyal <vgoyal@redhat.com> writes:
> On Tue, Mar 16, 2021 at 05:02:34PM +0000, Luis Henriques wrote:
>> When accidentally passing twice the same tag to qemu, kmemleak ended up
>> reporting a memory leak in virtiofs. Also, looking at the log I saw the
>> following error (that's when I realised the duplicated tag):
>>
>> virtiofs: probe of virtio5 failed with error -17
>>
>> Here's the kmemleak log for reference:
>>
>> unreferenced object 0xffff888103d47800 (size 1024):
>> comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
>> hex dump (first 32 bytes):
>> 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
>> ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................
>> backtrace:
>> [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
>> [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
>> [<000000004d6baf3c>] really_probe+0xea/0x430
>> [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
>> [<00000000196f47a7>] __driver_attach+0x98/0x140
>> [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
>> [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
>> [<0000000032b09ba7>] driver_register+0x8f/0xe0
>> [<00000000cdd55998>] 0xffffffffa002c013
>> [<000000000ea196a2>] do_one_initcall+0x64/0x2e0
>> [<0000000008f727ce>] do_init_module+0x5c/0x260
>> [<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
>> [<00000000ad2f48c6>] do_syscall_64+0x33/0x40
>> [<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Luis Henriques <lhenriques@suse.de>
>
> Hi Luis,
>
> Thanks for the report and the fix. So looks like leak is happening
> because we are not doing kfree(fs->vqs) in error path.
Yep!
>> ---
>> fs/fuse/virtio_fs.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
>> index 8868ac31a3c0..4e6ef9f24e84 100644
>> --- a/fs/fuse/virtio_fs.c
>> +++ b/fs/fuse/virtio_fs.c
>> @@ -899,7 +899,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
>>
>> out:
>> vdev->priv = NULL;
>> - kfree(fs);
>> + virtio_fs_put(fs);
>
> [ CC virtio-fs list ]
Oops, forgot to include it. Maybe it should be added to the MAINTAINERS
file (although IIRC it's not an open list).
> fs object is not fully formed. So calling virtio_fs_put() is little odd.
> I will expect it to be called if somebody takes a reference using _get()
> or in the final virtio_fs_remove() when creation reference should go
> away.
>
> How about open coding it and free fs->vqs explicitly. Something like
> as follows.
Ok, I'll send v2 later (I'm currently away from my devel workstation). To
be honest, my initial version was doing exactly what you're suggesting. I
decided to change to virtio_fs_put() because the refcount was already
initialised early in the function. Bad decision.
Cheers,
--
Luis
>
> @@ -896,7 +896,7 @@ static int virtio_fs_probe(struct virtio
> out_vqs:
> vdev->config->reset(vdev);
> virtio_fs_cleanup_vqs(vdev, fs);
> -
> + kfree(fs->vqs);
> out:
> vdev->priv = NULL;
> kfree(fs);
>
> Thanks
> Vivek
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Virtio-fs] [PATCH] virtiofs: fix memory leak in virtio_fs_probe()
@ 2021-03-16 21:14 ` Luis Henriques
0 siblings, 0 replies; 6+ messages in thread
From: Luis Henriques @ 2021-03-16 21:14 UTC (permalink / raw)
To: Vivek Goyal
Cc: Miklos Szeredi, linux-kernel, stable, virtualization,
virtio-fs-list, linux-fsdevel
Vivek Goyal <vgoyal@redhat.com> writes:
> On Tue, Mar 16, 2021 at 05:02:34PM +0000, Luis Henriques wrote:
>> When accidentally passing twice the same tag to qemu, kmemleak ended up
>> reporting a memory leak in virtiofs. Also, looking at the log I saw the
>> following error (that's when I realised the duplicated tag):
>>
>> virtiofs: probe of virtio5 failed with error -17
>>
>> Here's the kmemleak log for reference:
>>
>> unreferenced object 0xffff888103d47800 (size 1024):
>> comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
>> hex dump (first 32 bytes):
>> 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
>> ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................
>> backtrace:
>> [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
>> [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
>> [<000000004d6baf3c>] really_probe+0xea/0x430
>> [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
>> [<00000000196f47a7>] __driver_attach+0x98/0x140
>> [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
>> [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
>> [<0000000032b09ba7>] driver_register+0x8f/0xe0
>> [<00000000cdd55998>] 0xffffffffa002c013
>> [<000000000ea196a2>] do_one_initcall+0x64/0x2e0
>> [<0000000008f727ce>] do_init_module+0x5c/0x260
>> [<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
>> [<00000000ad2f48c6>] do_syscall_64+0x33/0x40
>> [<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Luis Henriques <lhenriques@suse.de>
>
> Hi Luis,
>
> Thanks for the report and the fix. So looks like leak is happening
> because we are not doing kfree(fs->vqs) in error path.
Yep!
>> ---
>> fs/fuse/virtio_fs.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
>> index 8868ac31a3c0..4e6ef9f24e84 100644
>> --- a/fs/fuse/virtio_fs.c
>> +++ b/fs/fuse/virtio_fs.c
>> @@ -899,7 +899,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
>>
>> out:
>> vdev->priv = NULL;
>> - kfree(fs);
>> + virtio_fs_put(fs);
>
> [ CC virtio-fs list ]
Oops, forgot to include it. Maybe it should be added to the MAINTAINERS
file (although IIRC it's not an open list).
> fs object is not fully formed. So calling virtio_fs_put() is little odd.
> I will expect it to be called if somebody takes a reference using _get()
> or in the final virtio_fs_remove() when creation reference should go
> away.
>
> How about open coding it and free fs->vqs explicitly. Something like
> as follows.
Ok, I'll send v2 later (I'm currently away from my devel workstation). To
be honest, my initial version was doing exactly what you're suggesting. I
decided to change to virtio_fs_put() because the refcount was already
initialised early in the function. Bad decision.
Cheers,
--
Luis
>
> @@ -896,7 +896,7 @@ static int virtio_fs_probe(struct virtio
> out_vqs:
> vdev->config->reset(vdev);
> virtio_fs_cleanup_vqs(vdev, fs);
> -
> + kfree(fs->vqs);
> out:
> vdev->priv = NULL;
> kfree(fs);
>
> Thanks
> Vivek
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-03-16 21:15 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-16 17:02 [PATCH] virtiofs: fix memory leak in virtio_fs_probe() Luis Henriques
2021-03-16 18:17 ` Vivek Goyal
2021-03-16 18:17 ` [Virtio-fs] " Vivek Goyal
2021-03-16 18:17 ` Vivek Goyal
2021-03-16 21:14 ` Luis Henriques
2021-03-16 21:14 ` [Virtio-fs] " Luis Henriques
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