mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

hw: misc: edu: fix 2 off-by-one errors

Browse Source 
In the case that size1 was zero, because of the explicit
'end1 > addr' check, the range check would fail and the error
message would read as shown below. The correct comparison
is 'end1 >= addr'.

EDU: DMA range 0x40000-0x3ffff out of bounds (0x40000-0x40fff)!

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1254
Signed-off-by: Chris Friedt <cfriedt@meta.com>
[thuth: Adjust patch with regards to the "end1 <= end2" check]
Message-ID: <20221018122551.94567-1-cfriedt@meta.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
This commit is contained in:
Chris Friedt 2022-10-18 08:25:49 -04:00 committed by Thomas Huth
parent 046bf2a618
commit 6982674159
1 changed files with 8 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
hw/misc/edu.c
View File

@ -103,19 +103,18 @@ static void edu_lower_irq(EduState *edu, uint32_t val)
}
}
static bool within(uint64_t addr, uint64_t start, uint64_t end)
{
return start <= addr && addr < end;
}
static void edu_check_range(uint64_t addr, uint64_t size1, uint64_t start,
uint64_t size2)
static void edu_check_range(uint64_t addr, uint64_t size1,
uint64_t start, uint64_t size2)
{
uint64_t end1 = addr + size1;
uint64_t end2 = start + size2;
if (within(addr, start, end2) &&
end1 > addr && end1 <= end2) {
/*
* 1. ensure we aren't overflowing
* 2. ensure that [addr, end1) is within [start, size2)
*/
if (end2 >= start && end1 >= addr &&
addr >= start && end1 <= end2) {
return;
}