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[Qemu-stable] [PATCH 1/5] multiboot: Reject kernels exceeding the addres
From: |
Kevin Wolf |
Subject: |
[Qemu-stable] [PATCH 1/5] multiboot: Reject kernels exceeding the address space |
Date: |
Wed, 14 Mar 2018 18:32:09 +0100 |
The code path with a manually set mh_load_addr in the Multiboot header
checks that load_end_addr <= load_addr, but the path where load_end_addr
is automatically detected if 0 is given in the header misses the
corresponding check. If the kernel binary size is larger than can fit in
the address space after load_addr, we ended up with a kernel_size that
is smaller than load_size, which means that we read the file into a too
small buffer.
Add a check to reject kernel files with such Multiboot headers.
Signed-off-by: Kevin Wolf <address@hidden>
---
hw/i386/multiboot.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c
index b9064264d8..1e215bf8d3 100644
--- a/hw/i386/multiboot.c
+++ b/hw/i386/multiboot.c
@@ -247,6 +247,10 @@ int load_multiboot(FWCfgState *fw_cfg,
}
mb_load_size = kernel_file_size - mb_kernel_text_offset;
}
+ if (mb_load_size > UINT32_MAX - mh_load_addr) {
+ error_report("kernel does not fit in address space");
+ exit(1);
+ }
if (mh_bss_end_addr) {
if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) {
error_report("invalid bss_end_addr address");
--
2.13.6
[Qemu-stable] [PATCH 2/5] multiboot: Check validity of mh_header_addr, Kevin Wolf, 2018/03/14
[Qemu-stable] [PATCH 3/5] tests/multiboot: Test exit code for every qemu run, Kevin Wolf, 2018/03/14
[Qemu-stable] [PATCH 5/5] tests/multiboot: Add .gitignore, Kevin Wolf, 2018/03/14