When unexpected situation happened (e.g. tx/rx irq happened while
DMAC is used), the usbhsf_pkt_handler() was possible to cause NULL
pointer dereference like the followings:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: Oops: 80000007 [#1] SMP ARM
Modules linked in: usb_f_acm u_serial g_serial libcomposite
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.5.0-rc6-00842-gac57066-dirty #63
Hardware name: Generic R8A7790 (Flattened Device Tree)
task: c0729c00 ti: c0724000 task.ti: c0724000
PC is at 0x0
LR is at usbhsf_pkt_handler+0xac/0x118
pc : [<00000000>] lr : [<c03257e0>] psr: 60000193
sp : c0725db8 ip : 00000000 fp : c0725df4
r10: 00000001 r9 : 00000193 r8 : ef3ccab4
r7 : ef3cca10 r6 : eea4586c r5 : 00000000 r4 : ef19ceb4
r3 : 00000000 r2 : 0000009c r1 : c0725dc4 r0 : ef19ceb4
This patch adds a condition to avoid the dereference.
Fixes: e73a989 ("usb: renesas_usbhs: add DMAEngine support")
Cc: <stable@xxxxxxxxxxxxxxx> # v3.1+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
drivers/usb/renesas_usbhs/fifo.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index b4de70e..0c25c01 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -190,7 +190,8 @@ static int usbhsf_pkt_handler(struct usbhs_pipe *pipe, int type)
goto __usbhs_pkt_handler_end;
}
- ret = func(pkt, &is_done);
+ if (likely(func))
+ ret = func(pkt, &is_done);
if (is_done)
__usbhsf_pkt_del(pkt);
--
1.9.1
