| Message ID | 1364768585-5177-6-git-send-email-agust@denx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Apr 01, 2013 at 12:23:05AM +0200, Anatolij Gustschin wrote: > mxcmci_dma_callback() is invoked by DMA drivers in soft-irq > context and can be interrupted by the mxcmci_irq() interrupt > which can finish the mmc request or data transfer and set > host->req or host->data pointers to NULL. Then mxcmci_data_done() > crashes with a null pointer dereferences. Protect all accesses > to host->req and host->data by spin locks. > > Also check host->data pointer in mxcmci_watchdog() before > dereferencing it. > > Signed-off-by: Anatolij Gustschin <agust@denx.de> This looks like a bugfix which should be first in this series. Sascha > --- > v2: > - only rebased > > drivers/mmc/host/mxcmmc.c | 31 ++++++++++++++++++++++++------- > 1 files changed, 24 insertions(+), 7 deletions(-) > > diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c > index 2861e0d..23deb2a 100644 > --- a/drivers/mmc/host/mxcmmc.c > +++ b/drivers/mmc/host/mxcmmc.c > @@ -694,24 +694,40 @@ static void mxcmci_datawork(struct work_struct *work) > > static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat) > { > - struct mmc_data *data = host->data; > + struct mmc_request *req; > int data_error; > + unsigned long flags; > + > + spin_lock_irqsave(&host->lock, flags); > > - if (!data) > + if (!host->data) { > + spin_unlock_irqrestore(&host->lock, flags); > return; > + } > + > + if (!host->req) { > + spin_unlock_irqrestore(&host->lock, flags); > + return; > + } > + > + req = host->req; > + if (!req->stop) > + host->req = NULL; /* we will handle finish req below */ > > data_error = mxcmci_finish_data(host, stat); > > + spin_unlock_irqrestore(&host->lock, flags); > + > mxcmci_read_response(host, stat); > host->cmd = NULL; > > - if (host->req->stop) { > - if (mxcmci_start_cmd(host, host->req->stop, 0)) { > - mxcmci_finish_request(host, host->req); > + if (req->stop) { > + if (mxcmci_start_cmd(host, req->stop, 0)) { > + mxcmci_finish_request(host, req); > return; > } > } else { > - mxcmci_finish_request(host, host->req); > + mxcmci_finish_request(host, req); > } > } > > @@ -1005,7 +1021,8 @@ static void mxcmci_watchdog(unsigned long data) > > /* Mark transfer as erroneus and inform the upper layers */ > > - host->data->error = -ETIMEDOUT; > + if (host->data) > + host->data->error = -ETIMEDOUT; > host->req = NULL; > host->cmd = NULL; > host->data = NULL; > -- > 1.7.5.4 > >
diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c index 2861e0d..23deb2a 100644 --- a/drivers/mmc/host/mxcmmc.c +++ b/drivers/mmc/host/mxcmmc.c @@ -694,24 +694,40 @@ static void mxcmci_datawork(struct work_struct *work) static void mxcmci_data_done(struct mxcmci_host *host, unsigned int stat) { - struct mmc_data *data = host->data; + struct mmc_request *req; int data_error; + unsigned long flags; + + spin_lock_irqsave(&host->lock, flags); - if (!data) + if (!host->data) { + spin_unlock_irqrestore(&host->lock, flags); return; + } + + if (!host->req) { + spin_unlock_irqrestore(&host->lock, flags); + return; + } + + req = host->req; + if (!req->stop) + host->req = NULL; /* we will handle finish req below */ data_error = mxcmci_finish_data(host, stat); + spin_unlock_irqrestore(&host->lock, flags); + mxcmci_read_response(host, stat); host->cmd = NULL; - if (host->req->stop) { - if (mxcmci_start_cmd(host, host->req->stop, 0)) { - mxcmci_finish_request(host, host->req); + if (req->stop) { + if (mxcmci_start_cmd(host, req->stop, 0)) { + mxcmci_finish_request(host, req); return; } } else { - mxcmci_finish_request(host, host->req); + mxcmci_finish_request(host, req); } } @@ -1005,7 +1021,8 @@ static void mxcmci_watchdog(unsigned long data) /* Mark transfer as erroneus and inform the upper layers */ - host->data->error = -ETIMEDOUT; + if (host->data) + host->data->error = -ETIMEDOUT; host->req = NULL; host->cmd = NULL; host->data = NULL;
mxcmci_dma_callback() is invoked by DMA drivers in soft-irq context and can be interrupted by the mxcmci_irq() interrupt which can finish the mmc request or data transfer and set host->req or host->data pointers to NULL. Then mxcmci_data_done() crashes with a null pointer dereferences. Protect all accesses to host->req and host->data by spin locks. Also check host->data pointer in mxcmci_watchdog() before dereferencing it. Signed-off-by: Anatolij Gustschin <agust@denx.de> --- v2: - only rebased drivers/mmc/host/mxcmmc.c | 31 ++++++++++++++++++++++++------- 1 files changed, 24 insertions(+), 7 deletions(-)