Commit 77795318 authored by Pavel Andrianov's avatar Pavel Andrianov Committed by Greg Kroah-Hartman
Browse files

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: default avatarPavel Andrianov <andrianov@ispras.ru>
Acked-by: default avatarVaishali Thakkar <vaishali.thakkar@oracle.com>
Reviewed-by: default avatarSamuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent da25a8ec
......@@ -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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