tty_port_tty_get() can return NULL after port hangup that may happen anytime. The patch adds checks that tty_port_tty_get() returns nonNULL around places where tty is actually used.
I have no actual hardware to test the patch, so I have updated rx side processing from common sense only. v2: rx handling updated according Alan Cox feedback. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <[email protected]> --- drivers/char/pcmcia/synclink_cs.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c index 0a484b4..a6b8dde 100644 --- a/drivers/char/pcmcia/synclink_cs.c +++ b/drivers/char/pcmcia/synclink_cs.c @@ -891,6 +891,14 @@ static void rx_ready_async(MGSLPC_INFO *info, int tcd, struct tty_struct *tty) int work = 0; struct mgsl_icount *icount = &info->icount; + if (!tty) { + /* tty is not available anymore */ + issue_command(info, CHA, CMD_RXRESET); + if (debug_level >= DEBUG_LEVEL_ISR) + printk("%s(%d):rx_ready_async(tty=NULL)\n",__FILE__,__LINE__); + return; + } + if (tcd) { /* early termination, get FIFO count from RBCL register */ fifo_count = (unsigned char)(read_reg(info, CHA+RBCL) & 0x1f); @@ -980,7 +988,7 @@ static void tx_done(MGSLPC_INFO *info, struct tty_struct *tty) else #endif { - if (tty->stopped || tty->hw_stopped) { + if (tty && (tty->stopped || tty->hw_stopped)) { tx_stop(info); return; } @@ -1000,7 +1008,7 @@ static void tx_ready(MGSLPC_INFO *info, struct tty_struct *tty) if (!info->tx_active) return; } else { - if (tty->stopped || tty->hw_stopped) { + if (tty && (tty->stopped || tty->hw_stopped)) { tx_stop(info); return; } @@ -1050,13 +1058,12 @@ static void cts_change(MGSLPC_INFO *info, struct tty_struct *tty) wake_up_interruptible(&info->status_event_wait_q); wake_up_interruptible(&info->event_wait_q); - if (info->port.flags & ASYNC_CTS_FLOW) { + if (tty && (info->port.flags & ASYNC_CTS_FLOW)) { if (tty->hw_stopped) { if (info->serial_signals & SerialSignal_CTS) { if (debug_level >= DEBUG_LEVEL_ISR) printk("CTS tx start..."); - if (tty) - tty->hw_stopped = 0; + tty->hw_stopped = 0; tx_start(info, tty); info->pending_bh |= BH_TRANSMIT; return; @@ -1065,8 +1072,7 @@ static void cts_change(MGSLPC_INFO *info, struct tty_struct *tty) if (!(info->serial_signals & SerialSignal_CTS)) { if (debug_level >= DEBUG_LEVEL_ISR) printk("CTS tx stop..."); - if (tty) - tty->hw_stopped = 1; + tty->hw_stopped = 1; tx_stop(info); } } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
