USB: ehci_brcm_hub_control: improve port index sanitizing
Subsystems (3)
PATCH v4 1/1 USB: ehci_brcm_hub_control: improve port index sanitizing
Due to (wIndex & 0xff) - 1 can get an integer greater than 0xf, this can cause array index to be out of bounds since the size of array port_status is 0xf. This change prevents a possible out-of-bounds pointer computation by forcing the use of a valid port number.
--- drivers/usb/host/ehci-brcm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
drivers/usb/host/ehci-brcm.c +5 -1
@@ -62,8 +62,12 @@ static int ehci_brcm_hub_control(u32 __iomem *status_reg;unsigned long flags;int retval, irq_disabled =0 ; +u32 temp; - status_reg = &ehci->regs->port_status[(wIndex &0xff ) -1 ]; + temp = (wIndex &0xff ) -1 ; +if (temp >=HCS_N_PORTS_MAX ) + temp =0 ; + status_reg = &ehci->regs->port_status[temp];/* * RESUME is cleared when GetPortStatus() is called 20ms after start
Signature · 1 line
2.30.1 (Apple Git-130)
Greg KH
maintainerQuoted 32 lines · Haimin Zhang
Due to (wIndex &
0xff) - 1 can get an integer greater than0xf, this can cause array index to be out of bounds since the size of arrayport_statusis0xf. This change prevents a possible out-of-bounds pointer computation by forcing the use of a valid port number.Reported-by TCS Robot <[email protected]>Signed-off-by Haimin Zhang <[email protected]>--- drivers/usb/host/ehci-brcm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)drivers/usb/host/ehci-brcm.c +5
-1@@ -62,8 +62,12 @@ static int ehci_brcm_hub_control(u32 __iomem *status_reg;unsigned long flags;int retval, irq_disabled =0 ; +u32 temp; - status_reg = &ehci->regs->port_status[(wIndex &0xff ) -1 ]; + temp = (wIndex &0xff ) -1 ; +if (temp >=HCS_N_PORTS_MAX ) + temp =0 ; + status_reg = &ehci->regs->port_status[temp];/* * RESUME is cleared when GetPortStatus() is called 20ms after start Signature · 1 line
2.30.1 (Apple Git-130)
Hi,
This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree.
You are receiving this message because of the following common error(s) as indicated below:
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Alan Stern
maintainerQuoted 4 lines · Haimin Zhang
Due to (wIndex &
0xff) - 1 can get an integer greater than0xf, this can cause array index to be out of bounds since the size of arrayport_statusis0xf. This change prevents a possible out-of-bounds pointer computation by forcing the use of a valid port number.
I would write 15 instead of 0xf. The size of the array is 15; see the definition of HCS_N_PORTS_MAX. (Yes, I realize the 0xf is equal to 15, but why force people to go out of their way to translate a hex number into decimal?)
Quoted 4 lines
Reported-by TCS Robot <[email protected]>Signed-off-by Haimin Zhang <[email protected]>---
You did not include the version change information here.
Quoted 8 lines
drivers/usb/host/ehci-brcm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)drivers/usb/host/ehci-brcm.c +0
-0
drivers/usb/host/ehci-brcm.c static int ehci_brcm_hub_control( · line 69
Quoted 9 lines
drivers/usb/host/ehci-brcm.c +4
-1@@ -62,8 +62,12 @@ static int ehci_brcm_hub_control(u32 __iomem *status_reg;unsigned long flags;int retval, irq_disabled =0 ; +u32 temp; - status_reg = &ehci->regs->port_status[(wIndex &0xff ) -1 ]; + temp = (wIndex &0xff ) -1 ; +if (temp >=HCS_N_PORTS_MAX ) + temp =0 ;
There ought to be a comment explaining why you are doing this (namely, to avoid an "index out of bounds" warning). The reason isn't automatically obvious.
Alan Stern
Quoted 7 lines
drivers/usb/host/ehci-brcm.c +1
-0+ status_reg = &ehci->regs->port_status[temp];/* * RESUME is cleared when GetPortStatus() is called 20ms after start Signature · 1 line
2.30.1 (Apple Git-130)
A message that is not in the archive (sent off-list or not yet received): CAB2z9eybMuHKj64OJhjcUTMR5Or5kR_PgCqHb-KPCuYrvOZ3ow@mail.gmail.com
Alan Stern
maintainerPATCH v5 1/1 USB: ehci_brcm_hub_control: Improve port index sanitizing
From: Haimin Zhang <[email protected]>
Due to (wIndex & 0xff) - 1 can get an integer greater than 15, this can cause array index to be out of bounds since the size of array port_status is 15. This change prevents a possible out-of-bounds pointer computation by forcing the use of a valid port number.
---
v5 (Alan Stern): Changed 0xf in patch description to 15. Added
comment explaining why the port index is sanitized.
drivers/usb/host/ehci-brcm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
drivers/usb/host/ehci-brcm.c +5 -1
@@ -62,8 +62,12 @@ static int ehci_brcm_hub_control(u32 __iomem *status_reg;unsigned long flags;int retval, irq_disabled =0 ; +u32 temp; - status_reg = &ehci->regs->port_status[(wIndex &0xff ) -1 ]; + temp = (wIndex &0xff ) -1 ; +if (temp >=HCS_N_PORTS_MAX )/* Avoid index-out-of-bounds warning */ + temp =0 ; + status_reg = &ehci->regs->port_status[temp];/* * RESUME is cleared when GetPortStatus() is called 20ms after start