diff options
| author | Linus Torvalds | 2021-02-12 11:03:30 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2021-02-12 11:03:30 -0800 |
| commit | 93908500b8da0423c9f0511130c8ab86d59576a0 (patch) | |
| tree | b67a591dfefc5463fd83f1725d4c4b37a66862e9 /arch/arm64 | |
| parent | dcc0b49040c70ad827a7f3d58a21b01fdb14e749 (diff) | |
| parent | 68d54ceeec0e5fee4fb8048e6a04c193f32525ca (diff) | |
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
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 6 | ||||
| -rw-r--r-- | arch/arm64/kernel/mte.c | 3 |
2 files changed, 3 insertions, 6 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index e99eddec0a46..3e6331b64932 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -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(); } diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index dc9ada64feed..80b62fe49dcf 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -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); |