File hw-scsi-scsi-disk-MODE_PAGE_ALLS-not-all.patch of Package qemu.28166

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File hw-scsi-scsi-disk-MODE_PAGE_ALLS-not-all.patch of Package qemu.28166

From: Mauro Matteo Cascella <mcascell@redhat.com>
Date: Thu, 4 Nov 2021 17:31:38 +0100
Subject: hw/scsi/scsi-disk: MODE_PAGE_ALLS not allowed in MODE SELECT commands

Git-commit: b3af7fdf9cc537f8f0dd3e2423d83f5c99a457e8
References: bsc#1192525

This avoids an off-by-one read of 'mode_sense_valid' buffer in
hw/scsi/scsi-disk.c:mode_sense_page().

Fixes: CVE-2021-3930
Cc: qemu-stable@nongnu.org
Reported-by: Alexander Bulekov <alxndr@bu.edu>
Fixes: a8f4bbe2900 ("scsi-disk: store valid mode pages in a table")
Fixes: #546
Reported-by: Qiuhao Li <Qiuhao.Li@outlook.com>
Signed-off-by: Mauro Matteo Cascella <mcascell@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
---
 hw/scsi/scsi-disk.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 7ab2be05b3ce3f4fad2212037b34..e2eb7f1b3967fecc70d05de84ace 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1100,6 +1100,7 @@ static int mode_sense_page(SCSIDiskState *s, int page, uint8_t **p_outbuf,
     uint8_t *p = *p_outbuf + 2;
     int length;
 
+    assert(page < ARRAY_SIZE(mode_sense_valid));
     if ((mode_sense_valid[page] & (1 << s->qdev.type)) == 0) {
         return -1;
     }
@@ -1441,6 +1442,11 @@ static int scsi_disk_check_mode_select(SCSIDiskState *s, int page,
         return -1;
     }
 
+    /* MODE_PAGE_ALLS is only valid for MODE SENSE commands */
+    if (page == MODE_PAGE_ALLS) {
+        return -1;
+    }
+
     p = mode_current;
     memset(mode_current, 0, inlen + 2);
     len = mode_sense_page(s, page, &p, 0);

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File hw-scsi-scsi-disk-MODE_PAGE_ALLS-not-all.patch of Package qemu.28166

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