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| author | Michael Anthony Knyszek <mknyszek@google.com> | 2024-10-24 14:11:39 +0000 |
|---|---|---|
| committer | Michael Knyszek <mknyszek@google.com> | 2024-10-24 16:55:08 +0000 |
| commit | fb2a7f8ce1b1abf1195ba61e40286985f1189fa8 (patch) | |
| tree | c9aa70e07e64300c4fe9064ec0b459ae67339583 /src/runtime/malloc.go | |
| parent | 06cb3fbe62396200ac0d11351fd2530498cdf681 (diff) | |
| download | go-fb2a7f8ce1b1abf1195ba61e40286985f1189fa8.tar.xz | |
runtime: fix ASAN poison calculation in mallocgc
A previous CL broke the ASAN poisoning calculation in mallocgc by not
taking into account a possible allocation header, so the beginning of
the following allocation could have been poisoned.
This mostly isn't a problem, actually, since the following slot would
usually just have an allocation header in it that programs shouldn't be
touching anyway, but if we're going a word-past-the-end at the end of a
span, we could be poisoning a valid heap allocation.
Change-Id: I76a4f59bcef01af513a1640c4c212c0eb6be85b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/622295
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Diffstat (limited to 'src/runtime/malloc.go')
| -rw-r--r-- | src/runtime/malloc.go | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go index 02c096a859..74decd54c4 100644 --- a/src/runtime/malloc.go +++ b/src/runtime/malloc.go @@ -1064,7 +1064,11 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer { if asanenabled { // Poison the space between the end of the requested size of x // and the end of the slot. Unpoison the requested allocation. - asanpoison(unsafe.Add(x, size-asanRZ), asanRZ+(elemsize-size)) + frag := elemsize - size + if typ != nil && typ.Pointers() && !heapBitsInSpan(elemsize) { + frag -= mallocHeaderSize + } + asanpoison(unsafe.Add(x, size-asanRZ), asanRZ+frag) asanunpoison(x, size-asanRZ) } |