From: Corey Wright Date: Sun, 28 Feb 2016 08:42:39 +0000 (-0600) Subject: proc: Fix ptrace-based permission checks for accessing task maps X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b048b93f0e5b249b0add0bde6ec7ec75a07eac9c;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git proc: Fix ptrace-based permission checks for accessing task maps Modify mm_access() calls in fs/proc/task_mmu.c and fs/proc/task_nommu.c to have the mode include PTRACE_MODE_FSCREDS so accessing /proc/pid/maps and /proc/pid/pagemap is not denied to all users. In backporting upstream commit caaee623 to pre-3.18 kernel versions it was overlooked that mm_access() is used in fs/proc/task_*mmu.c as those calls were removed in 3.18 (by upstream commit 29a40ace) and did not exist at the time of the original commit. Signed-off-by: Corey Wright Acked-by: Jann Horn Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9f285fb9bab3..b86db1236c7c 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -170,7 +170,7 @@ static void *m_start(struct seq_file *m, loff_t *pos) if (!priv->task) return ERR_PTR(-ESRCH); - mm = mm_access(priv->task, PTRACE_MODE_READ); + mm = mm_access(priv->task, PTRACE_MODE_READ_FSCREDS); if (!mm || IS_ERR(mm)) return mm; down_read(&mm->mmap_sem); @@ -1044,7 +1044,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, if (!pm.buffer) goto out_task; - mm = mm_access(task, PTRACE_MODE_READ); + mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); ret = PTR_ERR(mm); if (!mm || IS_ERR(mm)) goto out_free; diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 56123a6f462e..123c19890b14 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -223,7 +223,7 @@ static void *m_start(struct seq_file *m, loff_t *pos) if (!priv->task) return ERR_PTR(-ESRCH); - mm = mm_access(priv->task, PTRACE_MODE_READ); + mm = mm_access(priv->task, PTRACE_MODE_READ_FSCREDS); if (!mm || IS_ERR(mm)) { put_task_struct(priv->task); priv->task = NULL;