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authorYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>2016-03-10 11:30:14 +0900
committerFelipe Balbi <felipe.balbi@linux.intel.com>2016-03-30 16:02:37 +0300
commit894f2fc44f2f3f48c36c973b1123f6ab298be160 (patch)
tree4ca2d58c4ab5f9c8d30703e8c68dbf016396c42f
parent03d27ade4941076b34c823d63d91dc895731a595 (diff)
downloadlinux-894f2fc44f2f3f48c36c973b1123f6ab298be160.tar.gz
linux-894f2fc44f2f3f48c36c973b1123f6ab298be160.tar.xz
usb: renesas_usbhs: avoid NULL pointer derefernce in usbhsf_pkt_handler()
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@vger.kernel.org> # v3.1+ Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
-rw-r--r--drivers/usb/renesas_usbhs/fifo.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index b4de70ee16d3..0c25c01ade7a 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);