Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-09-20 15:03:04 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix PTRACE_PEEKMTETAGS access to an mmapped region before the first

Browse Source 
write.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE5RElWfyWxS+3PLO2a9axLQDIXvEFAmAmwyAACgkQa9axLQDI
 XvGGoQ/+O0K1SmqwSCEcq1l5imBCKVAj//kkBi761uZa5JFIueNxg+alfVSLqqah
 ZKBihhtOG+5VSa/BC5qP3qjqHz/5aLB3bFe5qHY3By8Iz+RfTROQJ8Otw/n8gwy4
 FkzBGg1gTqPwDpGOa14Y8YSmU7lkW2M6FPwECK/6Ek8zle8q/8NdFbath9b7tdPx
 JWST5MRWrqK6QO7MGvCJ5H1qd1isNSiFtFCdZS6r2wKpJl0nI47X/ncQsVFrTdHr
 BKvy8Hudc+sOOt6TljMBTUg8vwo6l3Fk6W6i9f3GgMMgpSUy8zH5anmWVyqSwguF
 2Uh2CA8bJqWxdOYQq21shTApz2tz9uwMpavlvLR3mnuvXgC4SVB0B0W6WxsW0fvX
 7p+ipZAbtcuifkVjn3XM9QVi3XNtot7Fg532YugtPDvh6uCNglw/26Ix3CdQBV5Z
 C2N4hATXDcmgank1P6dZ+i+y8dpWpAa/RXFqTWXBZDtKZmqT62xtRyhoZvZWlebs
 o6n1Ni5p+cYJRvyoNILhChZE6SNd4uAKrvGeSQmyf3zLo9pxU6fWyQUF3ZTtVhrF
 sdEP4KTKDkEl/dCfPkUIvZ/F0tIAGwPczzuDIny7+xzVlDMbKTMlGCky+s5CAKvh
 khxKeY+xtinYpfVNsTvVLKi8yFf5Um/DroEz6ItlXnRwhoXtDrg=
 =HYVs
 -----END PGP SIGNATURE-----

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fix from Catalin Marinas:
 "Fix PTRACE_PEEKMTETAGS access to an mmapped region before the first
  write"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mte: Allow PTRACE_PEEKMTETAGS access to the zero page
This commit is contained in:
Linus Torvalds 2021-02-12 11:03:30 -08:00
commit 93908500b8
2 changed files with 3 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm64/kernel/cpufeature.c
View File

@ -1701,16 +1701,12 @@ static void bti_enable(const struct arm64_cpu_capabilities *__unused)
#ifdef CONFIG_ARM64_MTE
static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
{
static bool cleared_zero_page = false;
/*
* Clear the tags in the zero page. This needs to be done via the
* linear map which has the Tagged attribute.
*/
if (!cleared_zero_page) {
cleared_zero_page = true;
if (!test_and_set_bit(PG_mte_tagged, &ZERO_PAGE(0)->flags))
mte_clear_page_tags(lm_alias(empty_zero_page));
}
kasan_init_hw_tags_cpu();
}

3
arch/arm64/kernel/mte.c
View File

@ -329,11 +329,12 @@ static int __access_remote_tags(struct mm_struct *mm, unsigned long addr,
* would cause the existing tags to be cleared if the page
* was never mapped with PROT_MTE.
*/
if (!test_bit(PG_mte_tagged, &page->flags)) {
if (!(vma->vm_flags & VM_MTE)) {
ret = -EOPNOTSUPP;
put_page(page);
break;
}
WARN_ON_ONCE(!test_bit(PG_mte_tagged, &page->flags));
/* limit access to the end of the page */
offset = offset_in_page(addr);