35 lines
1.2 KiB
Diff
35 lines
1.2 KiB
Diff
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From: Prasad J Pandit <pjp@fedoraproject.org>
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Date: Wed, 12 Oct 2016 11:28:08 +0530
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Subject: [PATCH] char: serial: check divider value against baud base
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16550A UART device uses an oscillator to generate frequencies
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(baud base), which decide communication speed. This speed could
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be changed by dividing it by a divider. If the divider is
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greater than the baud base, speed is set to zero, leading to a
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divide by zero error. Add check to avoid it.
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Reported-by: Huawei PSIRT <psirt@huawei.com>
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Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
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Message-Id: <1476251888-20238-1-git-send-email-ppandit@redhat.com>
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Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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(cherry picked from commit 3592fe0c919cf27a81d8e9f9b4f269553418bb01)
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---
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hw/char/serial.c | 3 ++-
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1 file changed, 2 insertions(+), 1 deletion(-)
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diff --git a/hw/char/serial.c b/hw/char/serial.c
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index 6d815b5..3998131 100644
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--- a/hw/char/serial.c
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+++ b/hw/char/serial.c
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@@ -152,8 +152,9 @@ static void serial_update_parameters(SerialState *s)
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int speed, parity, data_bits, stop_bits, frame_size;
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QEMUSerialSetParams ssp;
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- if (s->divider == 0)
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+ if (s->divider == 0 || s->divider > s->baudbase) {
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return;
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+ }
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/* Start bit. */
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frame_size = 1;
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