From b987718bbb1d0eabf95499b976212dd5f0120d75 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Mon, 22 May 2023 11:10:11 +0200 Subject: hw/scsi/lsi53c895a: Fix reentrancy issues in the LSI controller (CVE-2023-0330) We cannot use the generic reentrancy guard in the LSI code, so we have to manually prevent endless reentrancy here. The problematic lsi_execute_script() function has already a way to detect whether too many instructions have been executed - we just have to slightly change the logic here that it also takes into account if the function has been called too often in a reentrant way. The code in fuzz-lsi53c895a-test.c has been taken from an earlier patch by Mauro Matteo Cascella. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1563 Message-Id: <20230522091011.1082574-1-thuth@redhat.com> Reviewed-by: Stefan Hajnoczi Reviewed-by: Alexander Bulekov Signed-off-by: Thomas Huth --- tests/qtest/fuzz-lsi53c895a-test.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'tests') diff --git a/tests/qtest/fuzz-lsi53c895a-test.c b/tests/qtest/fuzz-lsi53c895a-test.c index 2012bd5..1b55928 100644 --- a/tests/qtest/fuzz-lsi53c895a-test.c +++ b/tests/qtest/fuzz-lsi53c895a-test.c @@ -9,6 +9,36 @@ #include "libqtest.h" /* + * This used to trigger a DMA reentrancy issue + * leading to memory corruption bugs like stack + * overflow or use-after-free + * https://gitlab.com/qemu-project/qemu/-/issues/1563 + */ +static void test_lsi_dma_reentrancy(void) +{ + QTestState *s; + + s = qtest_init("-M q35 -m 512M -nodefaults " + "-blockdev driver=null-co,node-name=null0 " + "-device lsi53c810 -device scsi-cd,drive=null0"); + + qtest_outl(s, 0xcf8, 0x80000804); /* PCI Command Register */ + qtest_outw(s, 0xcfc, 0x7); /* Enables accesses */ + qtest_outl(s, 0xcf8, 0x80000814); /* Memory Bar 1 */ + qtest_outl(s, 0xcfc, 0xff100000); /* Set MMIO Address*/ + qtest_outl(s, 0xcf8, 0x80000818); /* Memory Bar 2 */ + qtest_outl(s, 0xcfc, 0xff000000); /* Set RAM Address*/ + qtest_writel(s, 0xff000000, 0xc0000024); + qtest_writel(s, 0xff000114, 0x00000080); + qtest_writel(s, 0xff00012c, 0xff000000); + qtest_writel(s, 0xff000004, 0xff000114); + qtest_writel(s, 0xff000008, 0xff100014); + qtest_writel(s, 0xff10002f, 0x000000ff); + + qtest_quit(s); +} + +/* * This used to trigger a UAF in lsi_do_msgout() * https://gitlab.com/qemu-project/qemu/-/issues/972 */ @@ -124,5 +154,8 @@ int main(int argc, char **argv) qtest_add_func("fuzz/lsi53c895a/lsi_do_msgout_cancel_req", test_lsi_do_msgout_cancel_req); + qtest_add_func("fuzz/lsi53c895a/lsi_dma_reentrancy", + test_lsi_dma_reentrancy); + return g_test_run(); } -- cgit v1.1