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| author | Andy Lutomirski <luto@kernel.org> | 2016-09-30 10:58:58 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-10-20 09:21:41 +0200 |
| commit | d17af5056cf9e9fc05e68832f7c15687fcc12281 (patch) | |
| tree | 5849ec3001300e88b215f9d4e47e6b2b18e335fa | |
| parent | b18cb64ead400c01bf1580eeba330ace51f8087d (diff) | |
| download | linux-rpi3-d17af5056cf9e9fc05e68832f7c15687fcc12281.tar.gz linux-rpi3-d17af5056cf9e9fc05e68832f7c15687fcc12281.tar.bz2 linux-rpi3-d17af5056cf9e9fc05e68832f7c15687fcc12281.zip | |
mm: Change vm_is_stack_for_task() to vm_is_stack_for_current()
Asking for a non-current task's stack can't be done without races
unless the task is frozen in kernel mode. As far as I know,
vm_is_stack_for_task() never had a safe non-current use case.
The __unused annotation is because some KSTK_ESP implementations
ignore their parameter, which IMO is further justification for this
patch.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux API <linux-api@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Link: http://lkml.kernel.org/r/4c3f68f426e6c061ca98b4fc7ef85ffbb0a25b0c.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | include/linux/mm.h | 2 | ||||
| -rw-r--r-- | mm/util.c | 4 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 2 |
3 files changed, 5 insertions, 3 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index e9caec6a51e9..a658a5167bce 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1391,7 +1391,7 @@ static inline int stack_guard_page_end(struct vm_area_struct *vma, !vma_growsup(vma->vm_next, addr); } -int vma_is_stack_for_task(struct vm_area_struct *vma, struct task_struct *t); +int vma_is_stack_for_current(struct vm_area_struct *vma); extern unsigned long move_page_tables(struct vm_area_struct *vma, unsigned long old_addr, struct vm_area_struct *new_vma, diff --git a/mm/util.c b/mm/util.c index 662cddf914af..c174e8921995 100644 --- a/mm/util.c +++ b/mm/util.c @@ -230,8 +230,10 @@ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, } /* Check if the vma is being used as a stack by this task */ -int vma_is_stack_for_task(struct vm_area_struct *vma, struct task_struct *t) +int vma_is_stack_for_current(struct vm_area_struct *vma) { + struct task_struct * __maybe_unused t = current; + return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t)); } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 085057936287..09fd6108e421 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3557,7 +3557,7 @@ static int selinux_file_mprotect(struct vm_area_struct *vma, } else if (!vma->vm_file && ((vma->vm_start <= vma->vm_mm->start_stack && vma->vm_end >= vma->vm_mm->start_stack) || - vma_is_stack_for_task(vma, current))) { + vma_is_stack_for_current(vma))) { rc = current_has_perm(current, PROCESS__EXECSTACK); } else if (vma->vm_file && vma->anon_vma) { /* |