summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--fs/proc/array.c6
-rw-r--r--fs/proc/base.c160
-rw-r--r--fs/proc/fd.c27
-rw-r--r--fs/proc/internal.h2
-rw-r--r--fs/proc/namespaces.c12
5 files changed, 99 insertions, 108 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 90fb0c6b5f99..479ea8cb4ef4 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -482,6 +482,11 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
unsigned long flags;
int exit_code = task->exit_code;
struct signal_struct *sig = task->signal;
+ int ret;
+
+ ret = down_read_killable(&task->signal->exec_update_lock);
+ if (ret)
+ return ret;
state = *get_task_state(task);
vsize = eip = esp = 0;
@@ -657,6 +662,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
seq_puts(m, " 0");
seq_putc(m, '\n');
+ up_read(&task->signal->exec_update_lock);
if (mm)
mmput(mm);
return 0;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d9acfa89c894..5042f14d24f3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -218,33 +218,24 @@ static int get_task_root(struct task_struct *task, struct path *root)
return result;
}
-static int proc_cwd_link(struct dentry *dentry, struct path *path)
+static int proc_cwd_link(struct dentry *dentry, struct path *path,
+ struct task_struct *task)
{
- struct task_struct *task = get_proc_task(d_inode(dentry));
int result = -ENOENT;
- if (task) {
- task_lock(task);
- if (task->fs) {
- get_fs_pwd(task->fs, path);
- result = 0;
- }
- task_unlock(task);
- put_task_struct(task);
+ task_lock(task);
+ if (task->fs) {
+ get_fs_pwd(task->fs, path);
+ result = 0;
}
+ task_unlock(task);
return result;
}
-static int proc_root_link(struct dentry *dentry, struct path *path)
+static int proc_root_link(struct dentry *dentry, struct path *path,
+ struct task_struct *task)
{
- struct task_struct *task = get_proc_task(d_inode(dentry));
- int result = -ENOENT;
-
- if (task) {
- result = get_task_root(task, path);
- put_task_struct(task);
- }
- return result;
+ return get_task_root(task, path);
}
/*
@@ -423,18 +414,24 @@ static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
{
unsigned long wchan;
char symname[KSYM_NAME_LEN];
+ int err;
+ err = down_read_killable(&task->signal->exec_update_lock);
+ if (err)
+ return err;
if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
goto print0;
wchan = get_wchan(task);
if (wchan && !lookup_symbol_name(wchan, symname)) {
seq_puts(m, symname);
+ up_read(&task->signal->exec_update_lock);
return 0;
}
print0:
seq_putc(m, '0');
+ up_read(&task->signal->exec_update_lock);
return 0;
}
#endif /* CONFIG_KALLSYMS */
@@ -704,23 +701,6 @@ static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
/* Here the fs part begins */
/************************************************************************/
-/* permission checks */
-static bool proc_fd_access_allowed(struct inode *inode)
-{
- struct task_struct *task;
- bool allowed = false;
- /* Allow access to a task's file descriptors if it is us or we
- * may use ptrace attach to the process and find out that
- * information.
- */
- task = get_proc_task(inode);
- if (task) {
- allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
- put_task_struct(task);
- }
- return allowed;
-}
-
int proc_nochmod_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
{
@@ -1777,16 +1757,12 @@ static const struct file_operations proc_pid_set_comm_operations = {
.release = single_release,
};
-static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
+static int proc_exe_link(struct dentry *dentry, struct path *exe_path,
+ struct task_struct *task)
{
- struct task_struct *task;
struct file *exe_file;
- task = get_proc_task(d_inode(dentry));
- if (!task)
- return -ENOENT;
exe_file = get_task_exe_file(task);
- put_task_struct(task);
if (exe_file) {
*exe_path = exe_file->f_path;
path_get(&exe_file->f_path);
@@ -1796,26 +1772,42 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
return -ENOENT;
}
+static int call_proc_get_link(struct dentry *dentry, struct inode *inode, struct path *path_out)
+{
+ struct task_struct *task;
+ int ret;
+
+ task = get_proc_task(inode);
+ if (!task)
+ return -ENOENT;
+ ret = down_read_killable(&task->signal->exec_update_lock);
+ if (ret)
+ goto out_put_task;
+ if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
+ ret = -EACCES;
+ goto out;
+ }
+ ret = PROC_I(inode)->op.proc_get_link(dentry, path_out, task);
+
+out:
+ up_read(&task->signal->exec_update_lock);
+out_put_task:
+ put_task_struct(task);
+ return ret;
+}
+
static const char *proc_pid_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct path path;
- int error = -EACCES;
+ int error;
if (!dentry)
return ERR_PTR(-ECHILD);
-
- /* Are we allowed to snoop on the tasks file descriptors? */
- if (!proc_fd_access_allowed(inode))
- goto out;
-
- error = PROC_I(inode)->op.proc_get_link(dentry, &path);
- if (error)
- goto out;
-
- error = nd_jump_link(&path);
-out:
+ error = call_proc_get_link(dentry, inode, &path);
+ if (!error)
+ error = nd_jump_link(&path);
return ERR_PTR(error);
}
@@ -1849,17 +1841,11 @@ static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int b
struct inode *inode = d_inode(dentry);
struct path path;
- /* Are we allowed to snoop on the tasks file descriptors? */
- if (!proc_fd_access_allowed(inode))
- goto out;
-
- error = PROC_I(inode)->op.proc_get_link(dentry, &path);
- if (error)
- goto out;
-
- error = do_proc_readlink(&path, buffer, buflen);
- path_put(&path);
-out:
+ error = call_proc_get_link(dentry, inode, &path);
+ if (!error) {
+ error = do_proc_readlink(&path, buffer, buflen);
+ path_put(&path);
+ }
return error;
}
@@ -2250,21 +2236,16 @@ static const struct dentry_operations tid_map_files_dentry_operations = {
.d_delete = pid_delete_dentry,
};
-static int map_files_get_link(struct dentry *dentry, struct path *path)
+static int map_files_get_link(struct dentry *dentry, struct path *path,
+ struct task_struct *task)
{
unsigned long vm_start, vm_end;
struct vm_area_struct *vma;
- struct task_struct *task;
struct mm_struct *mm;
int rc;
rc = -ENOENT;
- task = get_proc_task(d_inode(dentry));
- if (!task)
- goto out;
-
mm = get_task_mm(task);
- put_task_struct(task);
if (!mm)
goto out;
@@ -2360,17 +2341,15 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
if (!task)
goto out;
- result = ERR_PTR(-EACCES);
- if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
- goto out_put_task;
-
result = ERR_PTR(-ENOENT);
if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
goto out_put_task;
- mm = get_task_mm(task);
- if (!mm)
+ mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
+ if (IS_ERR(mm)) {
+ result = ERR_CAST(mm);
goto out_put_task;
+ }
result = ERR_PTR(-EINTR);
if (mmap_read_lock_killable(mm))
@@ -2420,23 +2399,22 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
if (!task)
goto out;
- ret = -EACCES;
- if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
- goto out_put_task;
-
ret = 0;
if (!dir_emit_dots(file, ctx))
goto out_put_task;
- mm = get_task_mm(task);
- if (!mm)
+ mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
+ if (IS_ERR(mm)) {
+ ret = PTR_ERR(mm);
+ /* if the task has no mm, the directory should just be empty */
+ if (ret == -ESRCH)
+ ret = 0;
goto out_put_task;
+ }
ret = mmap_read_lock_killable(mm);
- if (ret) {
- mmput(mm);
- goto out_put_task;
- }
+ if (ret)
+ goto out_put_mm;
nr_files = 0;
@@ -2462,8 +2440,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
if (!p) {
ret = -ENOMEM;
mmap_read_unlock(mm);
- mmput(mm);
- goto out_put_task;
+ goto out_put_mm;
}
p->start = vma->vm_start;
@@ -2471,7 +2448,6 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
p->mode = vma->vm_file->f_mode;
}
mmap_read_unlock(mm);
- mmput(mm);
for (i = 0; i < nr_files; i++) {
char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */
@@ -2488,6 +2464,8 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
ctx->pos++;
}
+out_put_mm:
+ mmput(mm);
out_put_task:
put_task_struct(task);
out:
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 05c7513e77c7..0f9a1556f2a3 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -171,24 +171,19 @@ static const struct dentry_operations tid_fd_dentry_operations = {
.d_delete = pid_delete_dentry,
};
-static int proc_fd_link(struct dentry *dentry, struct path *path)
+static int proc_fd_link(struct dentry *dentry, struct path *path,
+ struct task_struct *task)
{
- struct task_struct *task;
int ret = -ENOENT;
-
- task = get_proc_task(d_inode(dentry));
- if (task) {
- unsigned int fd = proc_fd(d_inode(dentry));
- struct file *fd_file;
-
- fd_file = fget_task(task, fd);
- if (fd_file) {
- *path = fd_file->f_path;
- path_get(&fd_file->f_path);
- ret = 0;
- fput(fd_file);
- }
- put_task_struct(task);
+ unsigned int fd = proc_fd(d_inode(dentry));
+ struct file *fd_file;
+
+ fd_file = fget_task(task, fd);
+ if (fd_file) {
+ *path = fd_file->f_path;
+ path_get(&fd_file->f_path);
+ ret = 0;
+ fput(fd_file);
}
return ret;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 1edbabbdbc5d..b232e1098117 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -110,7 +110,7 @@ extern struct kmem_cache *proc_dir_entry_cache;
void pde_free(struct proc_dir_entry *pde);
union proc_op {
- int (*proc_get_link)(struct dentry *, struct path *);
+ int (*proc_get_link)(struct dentry *, struct path *, struct task_struct *);
int (*proc_show)(struct seq_file *m,
struct pid_namespace *ns, struct pid *pid,
struct task_struct *task);
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 39f4169f669f..2f46f1396744 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -55,6 +55,10 @@ static const char *proc_ns_get_link(struct dentry *dentry,
if (!task)
return ERR_PTR(-EACCES);
+ error = down_read_killable(&task->signal->exec_update_lock);
+ if (error)
+ goto out_put_task;
+
if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
goto out;
@@ -64,6 +68,8 @@ static const char *proc_ns_get_link(struct dentry *dentry,
error = nd_jump_link(&ns_path);
out:
+ up_read(&task->signal->exec_update_lock);
+out_put_task:
put_task_struct(task);
return ERR_PTR(error);
}
@@ -80,11 +86,17 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
if (!task)
return res;
+ res = down_read_killable(&task->signal->exec_update_lock);
+ if (res)
+ goto out_put_task;
+
if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
res = ns_get_name(name, sizeof(name), task, ns_ops);
if (res >= 0)
res = readlink_copy(buffer, buflen, name, strlen(name));
}
+ up_read(&task->signal->exec_update_lock);
+out_put_task:
put_task_struct(task);
return res;
}
generated by cgit v1.2.3 (git 2.39.1) at 2026-08-15 14:29:29 +0000