jmb/hardened_malloc
1
0
Fork 0
mirror of https://github.com/GrapheneOS/hardened_malloc.git synced 2025-11-04 09:46:32 +01:00
Code Issues Projects Releases Packages Wiki Activity

mte: note why 0 tag is excluded

Browse source
This commit is contained in:
Dmitry Muhomor 2023-10-30 12:31:12 +02:00 • committed by Daniel Micay
parent 009f2dad76
commit b560431c01
1 changed files with 2 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
h_malloc.c
View file

@ -577,7 +577,8 @@ static void *tag_and_clear_slab_slot(struct slab_metadata *metadata, void *slot_
// is constructed.
u8 *slot_tags = metadata->arm_mte_tags;
// Tag exclusion mask
// Tag exclusion mask. 0 tag is always excluded to detect accesses to slab memory via untagged
// pointers. Moreover, 0 tag is excluded in bionic via PR_MTE_TAG_MASK prctl
u64 tem = (1 << 0) | (1 << RESERVED_TAG);
// current or previous tag of left neighbor or 0 if there's no left neighbor or if it was never used