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Blame 0007-esp-check-command-buffer-length-before-write-CVE-201.patch

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From: Prasad J Pandit <pjp@fedoraproject.org>
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Date: Thu, 19 May 2016 16:09:30 +0530
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Subject: [PATCH] esp: check command buffer length before write(CVE-2016-4439)
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The 53C9X Fast SCSI Controller(FSC) comes with an internal 16-byte
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FIFO buffer. It is used to handle command and data transfer. While
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writing to this command buffer 's->cmdbuf[TI_BUFSZ=16]', a check
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was missing to validate input length. Add check to avoid OOB write
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access.
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Fixes CVE-2016-4439.
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Reported-by: Li Qiang <liqiang6-s@360.cn>
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Cc: qemu-stable@nongnu.org
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Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
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Message-Id: <1463654371-11169-2-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 c98c6c105f66f05aa0b7c1d2a4a3f716450907ef)
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---
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 hw/scsi/esp.c | 6 +++++-
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 1 file changed, 5 insertions(+), 1 deletion(-)
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diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
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index 8961be2..01497e6 100644
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--- a/hw/scsi/esp.c
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+++ b/hw/scsi/esp.c
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@@ -448,7 +448,11 @@ void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
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         break;
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     case ESP_FIFO:
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         if (s->do_cmd) {
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-            s->cmdbuf[s->cmdlen++] = val & 0xff;
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+            if (s->cmdlen < TI_BUFSZ) {
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+                s->cmdbuf[s->cmdlen++] = val & 0xff;
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+            } else {
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+                trace_esp_error_fifo_overrun();
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+            }
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         } else if (s->ti_size == TI_BUFSZ - 1) {
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             trace_esp_error_fifo_overrun();
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         } else {