diff options
Diffstat (limited to 'fs/proc/base.c')
| -rw-r--r-- | fs/proc/base.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 072dac45b102..2b7fe41740f5 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -954,6 +954,7 @@ static ssize_t environ_read(struct file *file, char __user *buf, unsigned long src = *ppos; int ret = 0; struct mm_struct *mm = file->private_data; + unsigned long env_start, env_end; /* Ensure the process spawned far enough to have an environment. */ if (!mm || !mm->env_end) @@ -966,19 +967,25 @@ static ssize_t environ_read(struct file *file, char __user *buf, ret = 0; if (!atomic_inc_not_zero(&mm->mm_users)) goto free; + + down_read(&mm->mmap_sem); + env_start = mm->env_start; + env_end = mm->env_end; + up_read(&mm->mmap_sem); + while (count > 0) { size_t this_len, max_len; int retval; - if (src >= (mm->env_end - mm->env_start)) + if (src >= (env_end - env_start)) break; - this_len = mm->env_end - (mm->env_start + src); + this_len = env_end - (env_start + src); max_len = min_t(size_t, PAGE_SIZE, count); this_len = min(max_len, this_len); - retval = access_remote_vm(mm, (mm->env_start + src), + retval = access_remote_vm(mm, (env_start + src), page, this_len, 0); if (retval <= 0) { @@ -3384,7 +3391,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) * used for the node /proc/<pid>/task/<tid>/comm. * It bypasses generic permission checks in the case where a task of the same * task group attempts to access the node. - * The rational behind this is that glibc and bionic access this node for + * The rationale behind this is that glibc and bionic access this node for * cross thread naming (pthread_set/getname_np(!self)). However, if * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0, * which locks out the cross thread naming implementation. |