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From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
To: Alexander Bulekov <alxndr@bu.edu>, qemu-devel@nongnu.org
Cc: Fam Zheng <fam@euphon.net>, Laurent Vivier <lvivier@redhat.com>,
	Thomas Huth <thuth@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH] tests/qtest: add one more test for the am53c974
Date: Wed, 7 Apr 2021 14:04:57 +0100	[thread overview]
Message-ID: <0c024eae-533b-f3fa-8878-9f90d283eef9@ilande.co.uk> (raw)
In-Reply-To: <20210402162052.264952-1-alxndr@bu.edu>

On 02/04/2021 17:20, Alexander Bulekov wrote:

> Original crash:
> qemu-fuzz-i386: ../hw/scsi/esp.c:791: void esp_transfer_data(SCSIRequest *, uint32_t): Assertion `!s->do_cmd' failed.
> ==257532== ERROR: libFuzzer: deadly signal
> __assert_fail assert/assert.c:101:3
> esp_transfer_data hw/scsi/esp.c:791:5
> scsi_req_data hw/scsi/scsi-bus.c:1412:9
> scsi_disk_emulate_read_data hw/scsi/scsi-disk.c:1407:9
> scsi_req_continue hw/scsi/scsi-bus.c:1394:9
> do_busid_cmd hw/scsi/esp.c:317:9
> handle_s_without_atn hw/scsi/esp.c:393:9
> esp_reg_write hw/scsi/esp.c:1029:13
> esp_pci_io_write hw/scsi/esp-pci.c:215:9
> memory_region_write_accessor softmmu/memory.c:491:5
> access_with_adjusted_size softmmu/memory.c:552:18
> memory_region_dispatch_write softmmu/memory.c:1502:16
> flatview_write_continue softmmu/physmem.c:2746:23
> flatview_write softmmu/physmem.c:2786:14
> address_space_write softmmu/physmem.c:2878:18
> cpu_outl softmmu/ioport.c:80:5
> 
> Based-on: <20210401074933.9923-1-mark.cave-ayland@ilande.co.uk>
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
>   tests/qtest/am53c974-test.c | 18 ++++++++++++++++++
>   1 file changed, 18 insertions(+)
> 
> The patch took care of the handle_satn_stop assert. Here's a test case
> for the other assert.

Even though I can't reproduce the assert() here, looking at the code I think I can 
see how do_cmd is not being reset when a DMA command is issued. Does the following 
solve the outstanding fuzzer asserts?

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 0037197bdb..b668acef82 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -357,6 +357,7 @@ static void handle_satn(ESPState *s)
      cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
      if (cmdlen > 0) {
          s->cmdfifo_cdb_offset = 1;
+        s->do_cmd = 0;
          do_cmd(s);
      } else if (cmdlen == 0) {
          s->do_cmd = 1;
@@ -390,6 +391,7 @@ static void handle_s_without_atn(ESPState *s)
      cmdlen = get_cmd(s, ESP_CMDFIFO_SZ);
      if (cmdlen > 0) {
          s->cmdfifo_cdb_offset = 0;
+        s->do_cmd = 0;
          do_busid_cmd(s, 0);
      } else if (cmdlen == 0) {
          s->do_cmd = 1;


ATB,

Mark.


  parent reply	other threads:[~2021-04-07 13:07 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01  7:49 [PATCH v3 00/11] esp: fix asserts/segfaults discovered by fuzzer Mark Cave-Ayland
2021-04-01  7:49 ` [PATCH v3 01/11] esp: always check current_req is not NULL before use in DMA callbacks Mark Cave-Ayland
2021-04-01  7:49 ` [PATCH v3 02/11] esp: rework write_response() to avoid using the FIFO for DMA transactions Mark Cave-Ayland
2021-04-01  8:26   ` Philippe Mathieu-Daudé
2021-04-01  7:49 ` [PATCH v3 03/11] esp: consolidate esp_cmdfifo_push() into esp_fifo_push() Mark Cave-Ayland
2021-04-01  8:15   ` Philippe Mathieu-Daudé
2021-04-01  8:50     ` Mark Cave-Ayland
2021-04-01  9:16       ` Philippe Mathieu-Daudé
2021-04-01  7:49 ` [PATCH v3 04/11] esp: consolidate esp_cmdfifo_pop() into esp_fifo_pop() Mark Cave-Ayland
2021-04-01  8:15   ` Philippe Mathieu-Daudé
2021-04-01  7:49 ` [PATCH v3 05/11] esp: introduce esp_fifo_pop_buf() and use it instead of fifo8_pop_buf() Mark Cave-Ayland
2021-04-01  9:34   ` Philippe Mathieu-Daudé
2021-04-01 10:51     ` Mark Cave-Ayland
2021-04-01 18:05       ` Philippe Mathieu-Daudé
2021-04-01  7:49 ` [PATCH v3 06/11] esp: ensure cmdfifo is not empty and current_dev is non-NULL Mark Cave-Ayland
2021-04-01  8:17   ` Philippe Mathieu-Daudé
2021-04-01  7:49 ` [PATCH v3 07/11] esp: don't underflow cmdfifo in do_cmd() Mark Cave-Ayland
2021-04-01  8:19   ` Philippe Mathieu-Daudé
2021-04-01  8:51     ` Mark Cave-Ayland
2021-04-01  7:49 ` [PATCH v3 08/11] esp: don't overflow cmdfifo in get_cmd() Mark Cave-Ayland
2021-04-01  8:19   ` Philippe Mathieu-Daudé
2021-04-01  8:56     ` Mark Cave-Ayland
2021-04-01  7:49 ` [PATCH v3 09/11] esp: don't overflow cmdfifo if TC is larger than the cmdfifo size Mark Cave-Ayland
2021-04-01  7:49 ` [PATCH v3 10/11] esp: don't reset async_len directly in esp_select() if cancelling request Mark Cave-Ayland
2021-04-01  7:49 ` [PATCH v3 11/11] tests/qtest: add tests for am53c974 device Mark Cave-Ayland
2021-04-01 16:55   ` Alexander Bulekov
2021-04-02  7:29     ` Mark Cave-Ayland
2021-04-01 17:00 ` [PATCH v3 00/11] esp: fix asserts/segfaults discovered by fuzzer Alexander Bulekov
2021-04-02  7:35   ` Mark Cave-Ayland
2021-04-02 16:20     ` [PATCH] tests/qtest: add one more test for the am53c974 Alexander Bulekov
2021-04-03 14:38       ` Mark Cave-Ayland
2021-04-07 12:08         ` Mark Cave-Ayland
2021-04-07 13:04       ` Mark Cave-Ayland [this message]
2021-04-07 14:49         ` Alexander Bulekov
2021-04-07 15:11           ` Mark Cave-Ayland

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