diff options
| author | Luigi Rizzo <lrizzo@google.com> | 2021-09-02 14:56:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-03 09:58:13 -0700 |
| commit | 5b78ed24e8ec48602c1d6f5a188e58d000c81e2b (patch) | |
| tree | fb2e4dea2199850c8ab0ca7492acab96a06a15a0 /security/tomoyo | |
| parent | e15710bf04063766f428048f4dad7b73b646203f (diff) | |
| download | linux-5b78ed24e8ec48602c1d6f5a188e58d000c81e2b.tar.gz | |
mm/pagemap: add mmap_assert_locked() annotations to find_vma*()
find_vma() and variants need protection when used. This patch adds mmap_assert_lock() calls in the functions. To make sure the invariant is satisfied, we also need to add a mmap_read_lock() around the get_user_pages_remote() call in get_arg_page(). The lock is not strictly necessary because the mm has been newly created, but the extra cost is limited because the same mutex was also acquired shortly before in __bprm_mm_init(), so it is hot and uncontended. [penguin-kernel@i-love.sakura.ne.jp: TOMOYO needs the same protection which get_arg_page() needs] Link: https://lkml.kernel.org/r/58bb6bf7-a57e-8a40-e74b-39584b415152@i-love.sakura.ne.jp Link: https://lkml.kernel.org/r/20210731175341.3458608-1-lrizzo@google.com Signed-off-by: Luigi Rizzo <lrizzo@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'security/tomoyo')
| -rw-r--r-- | security/tomoyo/domain.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c index 98d985895ec8..31af29f669d2 100644 --- a/security/tomoyo/domain.c +++ b/security/tomoyo/domain.c @@ -897,6 +897,9 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos, struct tomoyo_page_dump *dump) { struct page *page; +#ifdef CONFIG_MMU + int ret; +#endif /* dump->data is released by tomoyo_find_next_domain(). */ if (!dump->data) { @@ -909,11 +912,13 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos, /* * This is called at execve() time in order to dig around * in the argv/environment of the new proceess - * (represented by bprm). 'current' is the process doing - * the execve(). + * (represented by bprm). */ - if (get_user_pages_remote(bprm->mm, pos, 1, - FOLL_FORCE, &page, NULL, NULL) <= 0) + mmap_read_lock(bprm->mm); + ret = get_user_pages_remote(bprm->mm, pos, 1, + FOLL_FORCE, &page, NULL, NULL); + mmap_read_unlock(bprm->mm); + if (ret <= 0) return false; #else page = bprm->page[pos / PAGE_SIZE]; |