[PULL 01/12] hw/scsi/lsi53c895a: add missing decrement of reentrancy counter

Thomas Huth posted 12 patches 9 months, 3 weeks ago
Maintainers: Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, David Gibson <david@gibson.dropbear.id.au>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, Fam Zheng <fam@euphon.net>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Thomas Huth <thuth@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Richard Henderson <richard.henderson@linaro.org>, David Hildenbrand <david@redhat.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, "Alex Bennée" <alex.bennee@linaro.org>, Wainer dos Santos Moschetta <wainersm@redhat.com>, Beraldo Leal <bleal@redhat.com>, Ed Maste <emaste@freebsd.org>, Li-Wen Hsu <lwhsu@freebsd.org>, Warner Losh <imp@bsdimp.com>, Kyle Evans <kevans@freebsd.org>
[PULL 01/12] hw/scsi/lsi53c895a: add missing decrement of reentrancy counter
Posted by Thomas Huth 9 months, 3 weeks ago
From: Sven Schnelle <svens@stackframe.org>

When the maximum count of SCRIPTS instructions is reached, the code
stops execution and returns, but fails to decrement the reentrancy
counter. This effectively renders the SCSI controller unusable
because on next entry the reentrancy counter is still above the limit.

This bug was seen on HP-UX 10.20 which seems to trigger SCRIPTS
loops.

Fixes: b987718bbb ("hw/scsi/lsi53c895a: Fix reentrancy issues in the LSI controller (CVE-2023-0330)")
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Message-ID: <20240128202214.2644768-1-svens@stackframe.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 hw/scsi/lsi53c895a.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c
index 34e3b89287..d607a5f9fb 100644
--- a/hw/scsi/lsi53c895a.c
+++ b/hw/scsi/lsi53c895a.c
@@ -1159,6 +1159,7 @@ again:
         lsi_script_scsi_interrupt(s, LSI_SIST0_UDC, 0);
         lsi_disconnect(s);
         trace_lsi_execute_script_stop();
+        reentrancy_level--;
         return;
     }
     insn = read_dword(s, s->dsp);
-- 
2.43.0