mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-22 17:01:14 +00:00
pcmcia: synclink_cs: fix potential tty NULL dereference
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 <khoroshilov@ispras.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
08b79dd10b
commit
221b7b5796
1 changed files with 13 additions and 7 deletions
|
@ -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);
|
||||
}
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue