[PATCH 2/2] fix error in previous patches

From: Yoochan Lee
Date: Sat Dec 31 2022 - 04:22:23 EST


---
drivers/misc/hpilo.c | 68 ++++++++++++++++++++++++--------------------
drivers/misc/hpilo.h | 1 +
2 files changed, 38 insertions(+), 31 deletions(-)

diff --git a/drivers/misc/hpilo.c b/drivers/misc/hpilo.c
index b4a99676a642..d6691cbedb25 100644
--- a/drivers/misc/hpilo.c
+++ b/drivers/misc/hpilo.c
@@ -37,6 +37,7 @@ static const struct pci_device_id ilo_blacklist[] =3D {
{}
};

+static void ilo_delete(struct kref *kref);
static inline int get_entry_id(int entry)
{
return (entry & ENTRY_MASK_DESCRIPTOR) >> ENTRY_BITPOS_DESCRIPTOR;
@@ -532,34 +533,6 @@ static __poll_t ilo_poll(struct file *fp, poll_table *=
wait)
return 0;
}

-static void ilo_delete(struct kref *kref)
-{
- struct ilo_hwinfo *ilo_hw =3D container_of(kref, struct ilo_hwinfo, refcn=
t);
-
- clear_device(ilo_hw);
-
- minor =3D MINOR(ilo_hw->cdev.dev);
- for (i =3D minor; i < minor + max_ccb; i++)
- device_destroy(ilo_class, MKDEV(ilo_major, i));
-
- cdev_del(&ilo_hw->cdev);
- ilo_disable_interrupts(ilo_hw);
- free_irq(pdev->irq, ilo_hw);
- ilo_unmap_device(pdev, ilo_hw);
- pci_release_regions(pdev);
- /*
- * pci_disable_device(pdev) used to be here. But this PCI device has
- * two functions with interrupt lines connected to a single pin. The
- * other one is a USB host controller. So when we disable the PIN here
- * e.g. by rmmod hpilo, the controller stops working. It is because
- * the interrupt link is disabled in ACPI since it is not refcounted
- * yet. See acpi_pci_link_free_irq called from acpi_pci_irq_disable.
- */
- kfree(ilo_hw);
- ilo_hwdev[(minor / max_ccb)] =3D 0;
-
-}
-
static int ilo_close(struct inode *ip, struct file *fp)
{
int slot;
@@ -719,6 +692,39 @@ static void ilo_unmap_device(struct pci_dev
*pdev, struct ilo_hwinfo *hw)
pci_iounmap(pdev, hw->mmio_vaddr);
}

+static void ilo_delete(struct kref *kref)
+{
+ int i, minor;
+ struct ilo_hwinfo *ilo_hw =3D container_of(kref, struct ilo_hwinfo, refcn=
t);
+ struct pci_dev *pdev =3D ilo_hw->pdev;
+
+ if(!ilo_hw)
+ return;
+
+ clear_device(ilo_hw);
+
+ minor =3D MINOR(ilo_hw->cdev.dev);
+ for (i =3D minor; i < minor + max_ccb; i++)
+ device_destroy(ilo_class, MKDEV(ilo_major, i));
+
+ cdev_del(&ilo_hw->cdev);
+ ilo_disable_interrupts(ilo_hw);
+ free_irq(pdev->irq, ilo_hw);
+ ilo_unmap_device(pdev, ilo_hw);
+ pci_release_regions(pdev);
+ /*
+ * pci_disable_device(pdev) used to be here. But this PCI device has
+ * two functions with interrupt lines connected to a single pin. The
+ * other one is a USB host controller. So when we disable the PIN here
+ * e.g. by rmmod hpilo, the controller stops working. It is because
+ * the interrupt link is disabled in ACPI since it is not refcounted
+ * yet. See acpi_pci_link_free_irq called from acpi_pci_irq_disable.
+ */
+ kfree(ilo_hw);
+ ilo_hwdev[(minor / max_ccb)] =3D 0;
+
+}
+
static int ilo_map_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
{
int bar;
@@ -772,13 +778,12 @@ static int ilo_map_device(struct pci_dev *pdev,
struct ilo_hwinfo *hw)

static void ilo_remove(struct pci_dev *pdev)
{
- int i, minor;
struct ilo_hwinfo *ilo_hw =3D pci_get_drvdata(pdev);

if (!ilo_hw)
return;

- kref_put(&hw->refcnt, ilo_delete);
+ kref_put(&ilo_hw->refcnt, ilo_delete);
}

static int ilo_probe(struct pci_dev *pdev,
@@ -820,7 +825,8 @@ static int ilo_probe(struct pci_dev *pdev,
spin_lock_init(&ilo_hw->alloc_lock);
spin_lock_init(&ilo_hw->fifo_lock);
spin_lock_init(&ilo_hw->open_lock);
- kref_init(&iol_hw->refcnt);
+ kref_init(&ilo_hw->refcnt);
+ ilo_hw->pdev =3D pdev;

error =3D pci_enable_device(pdev);
if (error)
diff --git a/drivers/misc/hpilo.h b/drivers/misc/hpilo.h
index ebc677eb45ae..f8a857fb93eb 100644
--- a/drivers/misc/hpilo.h
+++ b/drivers/misc/hpilo.h
@@ -62,6 +62,7 @@ struct ilo_hwinfo {
spinlock_t fifo_lock;

struct cdev cdev;
+ struct pci_dev *pdev;
struct kref refcnt;
};

--
2.39.0

2022=EB=85=84 12=EC=9B=94 31=EC=9D=BC (=ED=86=A0) =EC=98=A4=ED=9B=84 5:56, =
Yoochan Lee <yoochan1026@xxxxxxxxx>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> Hi, there is some typos in my patch.
>
> Therefore, here are additional patches.
>
> diff --git a/drivers/misc/hpilo.c b/drivers/misc/hpilo.c
> index b4a99676a642..ea5bfbb231bd 100644
> --- a/drivers/misc/hpilo.c
> +++ b/drivers/misc/hpilo.c
> @@ -778,7 +778,7 @@ static void ilo_remove(struct pci_dev *pdev)
> if (!ilo_hw)
> return;
>
> - kref_put(&hw->refcnt, ilo_delete);
> + kref_put(&ilo_hw->refcnt, ilo_delete);
> }
>
> static int ilo_probe(struct pci_dev *pdev,
> @@ -820,7 +820,7 @@ static int ilo_probe(struct pci_dev *pdev,
> spin_lock_init(&ilo_hw->alloc_lock);
> spin_lock_init(&ilo_hw->fifo_lock);
> spin_lock_init(&ilo_hw->open_lock);
> - kref_init(&iol_hw->refcnt);
> + kref_init(&ilo_hw->refcnt);
>
> error =3D pci_enable_device(pdev);
> if (error)
>
> Sincerely,
> Yoocahn
>
>
> 2022=EB=85=84 12=EC=9B=94 31=EC=9D=BC (=ED=86=A0) =EC=98=A4=ED=9B=84 5:51=
, kernel test robot <lkp@xxxxxxxxx>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
> >
> > Hi Yoochan,
> >
> > Thank you for the patch! Perhaps something to improve:
> >
> > [auto build test WARNING on char-misc/char-misc-testing]
> > [also build test WARNING on char-misc/char-misc-next char-misc/char-mis=
c-linus soc/for-next linus/master v6.2-rc1 next-20221226]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> >
> > url: https://github.com/intel-lab-lkp/linux/commits/Yoochan-Lee/misc=
-hpilo-Fix-use-after-free-in-ilo_open/20221231-135458
> > patch link: https://lore.kernel.org/r/20221231055310.2040648-1-yooch=
an1026%40gmail.com
> > patch subject: [PATCH] misc: hpilo: Fix use-after-free in ilo_open
> > config: x86_64-rhel-8.3-bpf
> > compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
> > reproduce (this is a W=3D1 build):
> > # https://github.com/intel-lab-lkp/linux/commit/aca13e7e71e5c2b=
68742270a834fd67929850ef9
> > git remote add linux-review https://github.com/intel-lab-lkp/li=
nux
> > git fetch --no-tags linux-review Yoochan-Lee/misc-hpilo-Fix-use=
-after-free-in-ilo_open/20221231-135458
> > git checkout aca13e7e71e5c2b68742270a834fd67929850ef9
> > # save the config file
> > mkdir build_dir && cp config build_dir/.config
> > make W=3D1 O=3Dbuild_dir ARCH=3Dx86_64 olddefconfig
> > make W=3D1 O=3Dbuild_dir ARCH=3Dx86_64 SHELL=3D/bin/bash driver=
s/misc/
> >
> > If you fix the issue, kindly add following tag where applicable
> > | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >
> > All warnings (new ones prefixed by >>):
> >
> > drivers/misc/hpilo.c: In function 'ilo_delete':
> > drivers/misc/hpilo.c:541:9: error: 'minor' undeclared (first use in =
this function); did you mean 'iminor'?
> > 541 | minor =3D MINOR(ilo_hw->cdev.dev);
> > | ^~~~~
> > | iminor
> > drivers/misc/hpilo.c:541:9: note: each undeclared identifier is repo=
rted only once for each function it appears in
> > drivers/misc/hpilo.c:542:14: error: 'i' undeclared (first use in thi=
s function)
> > 542 | for (i =3D minor; i < minor + max_ccb; i++)
> > | ^
> > drivers/misc/hpilo.c:547:18: error: 'pdev' undeclared (first use in =
this function); did you mean 'cdev'?
> > 547 | free_irq(pdev->irq, ilo_hw);
> > | ^~~~
> > | cdev
> > drivers/misc/hpilo.c:548:9: error: implicit declaration of function =
'ilo_unmap_device' [-Werror=3Dimplicit-function-declaration]
> > 548 | ilo_unmap_device(pdev, ilo_hw);
> > | ^~~~~~~~~~~~~~~~
> > drivers/misc/hpilo.c: At top level:
> > drivers/misc/hpilo.c:715:13: warning: conflicting types for 'ilo_unm=
ap_device'; have 'void(struct pci_dev *, struct ilo_hwinfo *)'
> > 715 | static void ilo_unmap_device(struct pci_dev *pdev, struct il=
o_hwinfo *hw)
> > | ^~~~~~~~~~~~~~~~
> > drivers/misc/hpilo.c:715:13: error: static declaration of 'ilo_unmap=
_device' follows non-static declaration
> > drivers/misc/hpilo.c:548:9: note: previous implicit declaration of '=
ilo_unmap_device' with type 'void(struct pci_dev *, struct ilo_hwinfo *)'
> > 548 | ilo_unmap_device(pdev, ilo_hw);
> > | ^~~~~~~~~~~~~~~~
> > drivers/misc/hpilo.c: In function 'ilo_remove':
> > drivers/misc/hpilo.c:781:19: error: 'hw' undeclared (first use in th=
is function)
> > 781 | kref_put(&hw->refcnt, ilo_delete);
> > | ^~
> > >> drivers/misc/hpilo.c:775:16: warning: unused variable 'minor' [-Wunu=
sed-variable]
> > 775 | int i, minor;
> > | ^~~~~
> > >> drivers/misc/hpilo.c:775:13: warning: unused variable 'i' [-Wunused-=
variable]
> > 775 | int i, minor;
> > | ^
> > drivers/misc/hpilo.c: In function 'ilo_probe':
> > drivers/misc/hpilo.c:823:20: error: 'iol_hw' undeclared (first use i=
n this function); did you mean 'ilo_hw'?
> > 823 | kref_init(&iol_hw->refcnt);
> > | ^~~~~~
> > | ilo_hw
> > cc1: some warnings being treated as errors
> >
> >
> > vim +/minor +775 drivers/misc/hpilo.c
> >
> > 9f7048412163d8 David Altobelli 2009-08-17 714
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 @715 static void ilo_unmap_d=
evice(struct pci_dev *pdev, struct ilo_hwinfo *hw)
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 716 {
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 717 pci_iounmap(pde=
v, hw->db_vaddr);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 718 pci_iounmap(pde=
v, hw->ram_vaddr);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 719 pci_iounmap(pde=
v, hw->mmio_vaddr);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 720 }
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 721
> > 80c8ae28926652 Bill Pemberton 2012-11-19 722 static int ilo_map_devi=
ce(struct pci_dev *pdev, struct ilo_hwinfo *hw)
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 723 {
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 724 int bar;
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 725 unsigned long o=
ff;
> > 23d51b81815127 Matt Hsiao 2021-05-31 726 u8 pci_rev_id;
> > 23d51b81815127 Matt Hsiao 2021-05-31 727 int rc;
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 728
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 729 /* map the memo=
ry mapped i/o registers */
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 730 hw->mmio_vaddr =
=3D pci_iomap(pdev, 1, 0);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 731 if (hw->mmio_va=
ddr =3D=3D NULL) {
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 732 dev_err=
(&pdev->dev, "Error mapping mmio\n");
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 733 goto ou=
t;
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 734 }
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 735
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 736 /* map the adap=
ter shared memory region */
> > 23d51b81815127 Matt Hsiao 2021-05-31 737 rc =3D pci_read=
_config_byte(pdev, PCI_REVISION_ID, &pci_rev_id);
> > 23d51b81815127 Matt Hsiao 2021-05-31 738 if (rc !=3D 0) =
{
> > 23d51b81815127 Matt Hsiao 2021-05-31 739 dev_err=
(&pdev->dev, "Error reading PCI rev id: %d\n", rc);
> > 23d51b81815127 Matt Hsiao 2021-05-31 740 goto ou=
t;
> > 23d51b81815127 Matt Hsiao 2021-05-31 741 }
> > 23d51b81815127 Matt Hsiao 2021-05-31 742
> > 23d51b81815127 Matt Hsiao 2021-05-31 743 if (pci_rev_id =
>=3D PCI_REV_ID_NECHES) {
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 744 bar =3D=
5;
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 745 /* Last=
8k is reserved for CCBs */
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 746 off =3D=
pci_resource_len(pdev, bar) - 0x2000;
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 747 } else {
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 748 bar =3D=
2;
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 749 off =3D=
0;
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 750 }
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 751 hw->ram_vaddr =
=3D pci_iomap_range(pdev, bar, off, max_ccb * ILOHW_CCB_SZ);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 752 if (hw->ram_vad=
dr =3D=3D NULL) {
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 753 dev_err=
(&pdev->dev, "Error mapping shared mem\n");
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 754 goto mm=
io_free;
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 755 }
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 756
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 757 /* map the door=
bell aperture */
> > 98dcd59dd063dd Camuso, Tony 2012-06-10 758 hw->db_vaddr =
=3D pci_iomap(pdev, 3, max_ccb * ONE_DB_SIZE);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 759 if (hw->db_vadd=
r =3D=3D NULL) {
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 760 dev_err=
(&pdev->dev, "Error mapping doorbell\n");
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 761 goto ra=
m_free;
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 762 }
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 763
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 764 return 0;
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 765 ram_free:
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 766 pci_iounmap(pde=
v, hw->ram_vaddr);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 767 mmio_free:
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 768 pci_iounmap(pde=
v, hw->mmio_vaddr);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 769 out:
> > c9fef1cc3dd367 Rusk, Mark 2016-09-19 770 return -ENOMEM;
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 771 }
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 772
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 773 static void ilo_remove(=
struct pci_dev *pdev)
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 774 {
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 @775 int i, minor;
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 776 struct ilo_hwin=
fo *ilo_hw =3D pci_get_drvdata(pdev);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 777
> > ebf1b764aa5cb3 Mark Rusk 2012-11-06 778 if (!ilo_hw)
> > ebf1b764aa5cb3 Mark Rusk 2012-11-06 779 return;
> > ebf1b764aa5cb3 Mark Rusk 2012-11-06 780
> > aca13e7e71e5c2 Yoochan Lee 2022-12-31 @781 kref_put(&hw->r=
efcnt, ilo_delete);
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 782 }
> > 89bcb05d9bbf8b David Altobelli 2008-07-02 783
> >
> > --
> > 0-DAY CI Kernel Test Service
> > https://01.org/lkp