hw/ide/core.c (cmd_read_native_max): Avoid limited device parameters

Always use the native CHS device parameters for the ATA commands READ
NATIVE MAX ADDRESS and READ NATIVE MAX ADDRESS EXT, not those limited
by the ATA command INITIALIZE_DEVICE_PARAMETERS (introduced in patch
176e4961, hw/ide/core.c: Implement ATA INITIALIZE_DEVICE_PARAMETERS
command, 2022-07-07.)

As stated by the ATA/ATAPI specification, "[t]he native maximum is the
highest address accepted by the device in the factory default
condition."  Therefore this patch substitutes the native values in
drive_heads and drive_sectors before calling ide_set_sector().

One consequence of the prior behavior was that setting zero sectors
per track could lead to an FPE within ide_set_sector().  Thanks to
Alexander Bulekov for reporting this issue.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1243
Signed-off-by: Lev Kujawski <lkujaw@mailbox.org>
Message-ID: <20221010085229.2431276-1-lkujaw@mailbox.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 17 insertions, 4 deletions

diff --git a/hw/ide/core.c b/hw/ide/core.c
index e8cb2da..08d9218 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -1623,11 +1623,24 @@ static bool cmd_read_native_max(IDEState *s, uint8_t cmd)
     /* Refuse if no sectors are addressable (e.g. medium not inserted) */
     if (s->nb_sectors == 0) {
         ide_abort_command(s);
-        return true;
-    }
+    } else {
+        /*
+         * Save the active drive parameters, which may have been
+         * limited from their native counterparts by, e.g., INITIALIZE
+         * DEVICE PARAMETERS or SET MAX ADDRESS.
+         */
+        const int aheads = s->heads;
+        const int asectors = s->sectors;
 
-    ide_cmd_lba48_transform(s, lba48);
-    ide_set_sector(s, s->nb_sectors - 1);
+        s->heads = s->drive_heads;
+        s->sectors = s->drive_sectors;
+
+        ide_cmd_lba48_transform(s, lba48);
+        ide_set_sector(s, s->nb_sectors - 1);
+
+        s->heads = aheads;
+        s->sectors = asectors;
+    }
 
     return true;
 }