Commit 77795318 authored Sep 05, 2016 by Pavel Andrianov Committed by Greg Kroah-Hartman Sep 12, 2016

speakup: Add spinlock in synth_direct_store



All operations with synth buffer should be protected,
as there are global pointers, which should be modified atomically.

Found by Linux Driver Verification project (linuxtesting.org)

Signed-off-by: Pavel Andrianov <andrianov@ispras.ru>
Acked-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent da25a8ec

drivers/staging/speakup/kobjects.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -411,11 +411,13 @@ static ssize_t synth_direct_store(struct kobject *kobj,
		int len;
		int bytes;
		const char *ptr = buf;
		unsigned long flags;

		if (!synth)
		return -EPERM;

		len = strlen(buf);
		spin_lock_irqsave(&speakup_info.spinlock, flags);
		while (len > 0) {
		bytes = min_t(size_t, len, 250);
		strncpy(tmp, ptr, bytes);
		@@ -425,6 +427,7 @@ static ssize_t synth_direct_store(struct kobject *kobj,
		ptr += bytes;
		len -= bytes;
		}
		spin_unlock_irqrestore(&speakup_info.spinlock, flags);
		return count;
		}

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