diff options
| author | Daniella Lee <daniellalee111@gmail.com> | 2021-11-26 14:13:24 +0800 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2021-11-29 08:49:36 -0500 |
| commit | bacf58ca18f06f0b464466bf8c19945f19791feb (patch) | |
| tree | a4078449758e51e2598fc60bd7896d68a4f2bc1b | |
| parent | 0192d6677c383d812fb23f572fda4e449e89d3f1 (diff) | |
Fix bad overflow check in hw/pci/pcie.c
Orginal qemu commit hash:14d02cfbe4adaeebe7cb833a8cc71191352cf03b
In function pcie_add_capability, an assert contains the
"offset < offset + size" expression.
Both variable offset and variable size are uint16_t,
the comparison is always true due to type promotion.
The next expression may be the same.
It might be like this:
Thread 1 "qemu-system-x86" hit Breakpoint 1, pcie_add_capability (
dev=0x555557ce5f10, cap_id=1, cap_ver=2 '\002', offset=256, size=72)
at ../hw/pci/pcie.c:930
930 {
(gdb) n
931 assert(offset >= PCI_CONFIG_SPACE_SIZE);
(gdb) n
932 assert(offset < offset + size);
(gdb) p offset
$1 = 256
(gdb) p offset < offset + size
$2 = 1
(gdb) set offset=65533
(gdb) p offset < offset + size
$3 = 1
(gdb) p offset < (uint16_t)(offset + size)
$4 = 0
Signed-off-by: Daniella Lee <daniellalee111@gmail.com>
Message-Id: <20211126061324.47331-1-daniellalee111@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | hw/pci/pcie.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index c5ed266337..d7d73a31e4 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -929,8 +929,8 @@ void pcie_add_capability(PCIDevice *dev, uint16_t offset, uint16_t size) { assert(offset >= PCI_CONFIG_SPACE_SIZE); - assert(offset < offset + size); - assert(offset + size <= PCIE_CONFIG_SPACE_SIZE); + assert(offset < (uint16_t)(offset + size)); + assert((uint16_t)(offset + size) <= PCIE_CONFIG_SPACE_SIZE); assert(size >= 8); assert(pci_is_express(dev)); |