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-rw-r--r--fs/proc/base.c190
1 files changed, 126 insertions, 64 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 520978e49e9..a170450aadb 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -62,6 +62,7 @@
#include <linux/namespace.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
+#include <linux/rcupdate.h>
#include <linux/kallsyms.h>
#include <linux/mount.h>
#include <linux/security.h>
@@ -102,7 +103,9 @@ enum pid_directory_inos {
PROC_TGID_NUMA_MAPS,
PROC_TGID_MOUNTS,
PROC_TGID_WCHAN,
+#ifdef CONFIG_MMU
PROC_TGID_SMAPS,
+#endif
#ifdef CONFIG_SCHEDSTATS
PROC_TGID_SCHEDSTAT,
#endif
@@ -119,7 +122,6 @@ enum pid_directory_inos {
#ifdef CONFIG_AUDITSYSCALL
PROC_TGID_LOGINUID,
#endif
- PROC_TGID_FD_DIR,
PROC_TGID_OOM_SCORE,
PROC_TGID_OOM_ADJUST,
PROC_TID_INO,
@@ -141,7 +143,9 @@ enum pid_directory_inos {
PROC_TID_NUMA_MAPS,
PROC_TID_MOUNTS,
PROC_TID_WCHAN,
+#ifdef CONFIG_MMU
PROC_TID_SMAPS,
+#endif
#ifdef CONFIG_SCHEDSTATS
PROC_TID_SCHEDSTAT,
#endif
@@ -158,9 +162,11 @@ enum pid_directory_inos {
#ifdef CONFIG_AUDITSYSCALL
PROC_TID_LOGINUID,
#endif
- PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
PROC_TID_OOM_SCORE,
PROC_TID_OOM_ADJUST,
+
+ /* Add new entries before this */
+ PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
};
struct pid_entry {
@@ -193,7 +199,9 @@ static struct pid_entry tgid_base_stuff[] = {
E(PROC_TGID_ROOT, "root", S_IFLNK|S_IRWXUGO),
E(PROC_TGID_EXE, "exe", S_IFLNK|S_IRWXUGO),
E(PROC_TGID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+#ifdef CONFIG_MMU
E(PROC_TGID_SMAPS, "smaps", S_IFREG|S_IRUGO),
+#endif
#ifdef CONFIG_SECURITY
E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
#endif
@@ -233,7 +241,9 @@ static struct pid_entry tid_base_stuff[] = {
E(PROC_TID_ROOT, "root", S_IFLNK|S_IRWXUGO),
E(PROC_TID_EXE, "exe", S_IFLNK|S_IRWXUGO),
E(PROC_TID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+#ifdef CONFIG_MMU
E(PROC_TID_SMAPS, "smaps", S_IFREG|S_IRUGO),
+#endif
#ifdef CONFIG_SECURITY
E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
#endif
@@ -282,30 +292,36 @@ static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsm
files = get_files_struct(task);
if (files) {
- spin_lock(&files->file_lock);
+ rcu_read_lock();
file = fcheck_files(files, fd);
if (file) {
*mnt = mntget(file->f_vfsmnt);
*dentry = dget(file->f_dentry);
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
put_files_struct(files);
return 0;
}
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
put_files_struct(files);
}
return -ENOENT;
}
-static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
+static struct fs_struct *get_fs_struct(struct task_struct *task)
{
struct fs_struct *fs;
- int result = -ENOENT;
- task_lock(proc_task(inode));
- fs = proc_task(inode)->fs;
+ task_lock(task);
+ fs = task->fs;
if(fs)
atomic_inc(&fs->count);
- task_unlock(proc_task(inode));
+ task_unlock(task);
+ return fs;
+}
+
+static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
+{
+ struct fs_struct *fs = get_fs_struct(proc_task(inode));
+ int result = -ENOENT;
if (fs) {
read_lock(&fs->lock);
*mnt = mntget(fs->pwdmnt);
@@ -319,13 +335,55 @@ static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfs
static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
+ struct fs_struct *fs = get_fs_struct(proc_task(inode));
+ int result = -ENOENT;
+ if (fs) {
+ read_lock(&fs->lock);
+ *mnt = mntget(fs->rootmnt);
+ *dentry = dget(fs->root);
+ read_unlock(&fs->lock);
+ result = 0;
+ put_fs_struct(fs);
+ }
+ return result;
+}
+
+
+/* Same as proc_root_link, but this addionally tries to get fs from other
+ * threads in the group */
+static int proc_task_root_link(struct inode *inode, struct dentry **dentry,
+ struct vfsmount **mnt)
+{
struct fs_struct *fs;
int result = -ENOENT;
- task_lock(proc_task(inode));
- fs = proc_task(inode)->fs;
- if(fs)
+ struct task_struct *leader = proc_task(inode);
+
+ task_lock(leader);
+ fs = leader->fs;
+ if (fs) {
atomic_inc(&fs->count);
- task_unlock(proc_task(inode));
+ task_unlock(leader);
+ } else {
+ /* Try to get fs from other threads */
+ task_unlock(leader);
+ read_lock(&tasklist_lock);
+ if (pid_alive(leader)) {
+ struct task_struct *task = leader;
+
+ while ((task = next_thread(task)) != leader) {
+ task_lock(task);
+ fs = task->fs;
+ if (fs) {
+ atomic_inc(&fs->count);
+ task_unlock(task);
+ break;
+ }
+ task_unlock(task);
+ }
+ }
+ read_unlock(&tasklist_lock);
+ }
+
if (fs) {
read_lock(&fs->lock);
*mnt = mntget(fs->rootmnt);
@@ -337,6 +395,7 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
return result;
}
+
#define MAY_PTRACE(task) \
(task == current || \
(task->parent == current && \
@@ -344,33 +403,6 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
(task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
security_ptrace(current,task) == 0))
-static int may_ptrace_attach(struct task_struct *task)
-{
- int retval = 0;
-
- task_lock(task);
-
- if (!task->mm)
- goto out;
- if (((current->uid != task->euid) ||
- (current->uid != task->suid) ||
- (current->uid != task->uid) ||
- (current->gid != task->egid) ||
- (current->gid != task->sgid) ||
- (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE))
- goto out;
- rmb();
- if (task->mm->dumpable != 1 && !capable(CAP_SYS_PTRACE))
- goto out;
- if (security_ptrace(current, task))
- goto out;
-
- retval = 1;
-out:
- task_unlock(task);
- return retval;
-}
-
static int proc_pid_environ(struct task_struct *task, char * buffer)
{
int res = 0;
@@ -380,7 +412,7 @@ static int proc_pid_environ(struct task_struct *task, char * buffer)
if (len > PAGE_SIZE)
len = PAGE_SIZE;
res = access_process_vm(task, mm->env_start, buffer, len, 0);
- if (!may_ptrace_attach(task))
+ if (!ptrace_may_attach(task))
res = -ESRCH;
mmput(mm);
}
@@ -495,14 +527,14 @@ static int proc_oom_score(struct task_struct *task, char *buffer)
/* permission checks */
-static int proc_check_root(struct inode *inode)
+/* If the process being read is separated by chroot from the reading process,
+ * don't let the reader access the threads.
+ */
+static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
{
- struct dentry *de, *base, *root;
- struct vfsmount *our_vfsmnt, *vfsmnt, *mnt;
+ struct dentry *de, *base;
+ struct vfsmount *our_vfsmnt, *mnt;
int res = 0;
-
- if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
- return -ENOENT;
read_lock(&current->fs->lock);
our_vfsmnt = mntget(current->fs->rootmnt);
base = dget(current->fs->root);
@@ -535,6 +567,16 @@ out:
goto exit;
}
+static int proc_check_root(struct inode *inode)
+{
+ struct dentry *root;
+ struct vfsmount *vfsmnt;
+
+ if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
+ return -ENOENT;
+ return proc_check_chroot(root, vfsmnt);
+}
+
static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
{
if (generic_permission(inode, mask, NULL) != 0)
@@ -542,6 +584,20 @@ static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
return proc_check_root(inode);
}
+static int proc_task_permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+ struct dentry *root;
+ struct vfsmount *vfsmnt;
+
+ if (generic_permission(inode, mask, NULL) != 0)
+ return -EACCES;
+
+ if (proc_task_root_link(inode, &root, &vfsmnt))
+ return -ENOENT;
+
+ return proc_check_chroot(root, vfsmnt);
+}
+
extern struct seq_operations proc_pid_maps_op;
static int maps_open(struct inode *inode, struct file *file)
{
@@ -582,6 +638,7 @@ static struct file_operations proc_numa_maps_operations = {
};
#endif
+#ifdef CONFIG_MMU
extern struct seq_operations proc_pid_smaps_op;
static int smaps_open(struct inode *inode, struct file *file)
{
@@ -600,6 +657,7 @@ static struct file_operations proc_smaps_operations = {
.llseek = seq_lseek,
.release = seq_release,
};
+#endif
extern struct seq_operations mounts_op;
static int mounts_open(struct inode *inode, struct file *file)
@@ -683,7 +741,7 @@ static ssize_t mem_read(struct file * file, char __user * buf,
int ret = -ESRCH;
struct mm_struct *mm;
- if (!MAY_PTRACE(task) || !may_ptrace_attach(task))
+ if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
goto out;
ret = -ENOMEM;
@@ -709,7 +767,7 @@ static ssize_t mem_read(struct file * file, char __user * buf,
this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
retval = access_process_vm(task, src, page, this_len, 0);
- if (!retval || !MAY_PTRACE(task) || !may_ptrace_attach(task)) {
+ if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
if (!ret)
ret = -EIO;
break;
@@ -747,7 +805,7 @@ static ssize_t mem_write(struct file * file, const char * buf,
struct task_struct *task = proc_task(file->f_dentry->d_inode);
unsigned long dst = *ppos;
- if (!MAY_PTRACE(task) || !may_ptrace_attach(task))
+ if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
return -ESRCH;
page = (char *)__get_free_page(GFP_USER);
@@ -1064,6 +1122,7 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
int retval;
char buf[NUMBUF];
struct files_struct * files;
+ struct fdtable *fdt;
retval = -ENOENT;
if (!pid_alive(p))
@@ -1086,15 +1145,16 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
files = get_files_struct(p);
if (!files)
goto out;
- spin_lock(&files->file_lock);
+ rcu_read_lock();
+ fdt = files_fdtable(files);
for (fd = filp->f_pos-2;
- fd < files->max_fds;
+ fd < fdt->max_fds;
fd++, filp->f_pos++) {
unsigned int i,j;
if (!fcheck_files(files, fd))
continue;
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
j = NUMBUF;
i = fd;
@@ -1106,12 +1166,12 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
- spin_lock(&files->file_lock);
+ rcu_read_lock();
break;
}
- spin_lock(&files->file_lock);
+ rcu_read_lock();
}
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
put_files_struct(files);
}
out:
@@ -1286,9 +1346,9 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
files = get_files_struct(task);
if (files) {
- spin_lock(&files->file_lock);
+ rcu_read_lock();
if (fcheck_files(files, fd)) {
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
put_files_struct(files);
if (task_dumpable(task)) {
inode->i_uid = task->euid;
@@ -1300,7 +1360,7 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
security_task_to_inode(task, inode);
return 1;
}
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
put_files_struct(files);
}
d_drop(dentry);
@@ -1392,7 +1452,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
if (!files)
goto out_unlock;
inode->i_mode = S_IFLNK;
- spin_lock(&files->file_lock);
+ rcu_read_lock();
file = fcheck_files(files, fd);
if (!file)
goto out_unlock2;
@@ -1400,7 +1460,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
inode->i_mode |= S_IRUSR | S_IXUSR;
if (file->f_mode & 2)
inode->i_mode |= S_IWUSR | S_IXUSR;
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
put_files_struct(files);
inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
@@ -1410,7 +1470,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
return NULL;
out_unlock2:
- spin_unlock(&files->file_lock);
+ rcu_read_unlock();
put_files_struct(files);
out_unlock:
iput(inode);
@@ -1441,7 +1501,7 @@ static struct inode_operations proc_fd_inode_operations = {
static struct inode_operations proc_task_inode_operations = {
.lookup = proc_task_lookup,
- .permission = proc_permission,
+ .permission = proc_task_permission,
};
#ifdef CONFIG_SECURITY
@@ -1631,10 +1691,12 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
case PROC_TGID_MOUNTS:
inode->i_fop = &proc_mounts_operations;
break;
+#ifdef CONFIG_MMU
case PROC_TID_SMAPS:
case PROC_TGID_SMAPS:
inode->i_fop = &proc_smaps_operations;
break;
+#endif
#ifdef CONFIG_SECURITY
case PROC_TID_ATTR:
inode->i_nlink = 2;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-02-21 23:49:54 +0000