Hi Felipe, > Hi Yoshihiro, > > Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> writes: > > [ text/plain ] > > 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. > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > > is this a regression fix ? Do we need it in current -rc (it's getting > late for that, actually), do we need a Cc: <stable> here ? > > Same questions are valid for the other patch in this series. Thank you for the review. This is a potential problem fix. This issue is possible to cause the first DMA supporting (e73a989 usb: renesas_usbhs: add DMAEngine support) at 2011, I think. We don't need in current -rc because I also think this is too late for it. I'm not sure we need a CC here. Best regards, Yoshihiro Shimoda > -- > balbi
