2021-03-17 08:45:25

by Luis Henriques

[permalink] [raw]
Subject: [PATCH v2] virtiofs: fix memory leak in virtio_fs_probe()

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: [email protected]
Signed-off-by: Luis Henriques <[email protected]>
---
Changes since v1:
- Use kfree() to free fs->vqs instead of calling virtio_fs_put()

fs/fuse/virtio_fs.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 8868ac31a3c0..989ef4f88636 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -896,6 +896,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
out_vqs:
vdev->config->reset(vdev);
virtio_fs_cleanup_vqs(vdev, fs);
+ kfree(fs->vqs);

out:
vdev->priv = NULL;


2021-03-17 09:39:29

by Stefan Hajnoczi

[permalink] [raw]
Subject: Re: [PATCH v2] virtiofs: fix memory leak in virtio_fs_probe()

On Wed, Mar 17, 2021 at 08:44:43AM +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: [email protected]
> Signed-off-by: Luis Henriques <[email protected]>
> ---
> Changes since v1:
> - Use kfree() to free fs->vqs instead of calling virtio_fs_put()
>
> fs/fuse/virtio_fs.c | 1 +
> 1 file changed, 1 insertion(+)

Reviewed-by: Stefan Hajnoczi <[email protected]>


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2021-03-17 12:36:29

by Vivek Goyal

[permalink] [raw]
Subject: Re: [PATCH v2] virtiofs: fix memory leak in virtio_fs_probe()

On Wed, Mar 17, 2021 at 08:44:43AM +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: [email protected]
> Signed-off-by: Luis Henriques <[email protected]>

Reviewed-by: Vivek Goyal <[email protected]>

Thanks
Vivek

> ---
> Changes since v1:
> - Use kfree() to free fs->vqs instead of calling virtio_fs_put()
>
> fs/fuse/virtio_fs.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
> index 8868ac31a3c0..989ef4f88636 100644
> --- a/fs/fuse/virtio_fs.c
> +++ b/fs/fuse/virtio_fs.c
> @@ -896,6 +896,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
> out_vqs:
> vdev->config->reset(vdev);
> virtio_fs_cleanup_vqs(vdev, fs);
> + kfree(fs->vqs);
>
> out:
> vdev->priv = NULL;
>

2021-04-13 03:24:27

by Miklos Szeredi

[permalink] [raw]
Subject: Re: [PATCH v2] virtiofs: fix memory leak in virtio_fs_probe()

On Wed, Mar 17, 2021 at 9:43 AM Luis Henriques <[email protected]> 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: [email protected]
> Signed-off-by: Luis Henriques <[email protected]>
> ---
> Changes since v1:
> - Use kfree() to free fs->vqs instead of calling virtio_fs_put()

Applied, thanks.

Miklos