The data race happens on ps2dev->cmdcnt and ps2dev->cmdbuf contents. __ps2_command reads that data concurrently with the interrupt handler. As the result, for example, if a response arrives just after the timeout, __ps2_command can copy out garbage from ps2dev->cmdbuf but then see that ps2dev->cmdcnt is 0 and return success. Stop the interrupt handler with serio_pause_rx() before reading the results. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> --- drivers/input/serio/libps2.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c index 7551699..8f93336 100644 --- a/drivers/input/serio/libps2.c +++ b/drivers/input/serio/libps2.c @@ -234,17 +234,19 @@ int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command) !(ps2dev->flags & PS2_FLAG_CMD), timeout); } + serio_pause_rx(ps2dev->serio); if (param) for (i = 0; i < receive; i++) param[i] = ps2dev->cmdbuf[(receive - 1) - i]; if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) - goto out; - + goto out_paused; rc = 0; + goto out_paused; out: serio_pause_rx(ps2dev->serio); +out_paused: ps2dev->flags = 0; serio_continue_rx(ps2dev->serio); -- 2.5.0.457.gab17608 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
