diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 430963e0e8c3..996f3cfe7030 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -51,6 +51,8 @@ fixes/update part 1.1 Stefani Seibold June 9 2009 4 Configuring procfs 4.1 Mount options + 5 Filesystem behavior + Preface ======= @@ -2143,28 +2145,80 @@ The following mount options are supported: ========= ======================================================== hidepid= Set /proc// access mode. gid= Set the group authorized to learn processes information. + subset= Show only the specified subset of procfs. ========= ======================================================== -hidepid=0 means classic mode - everybody may access all /proc// directories -(default). +hidepid=off or hidepid=0 means classic mode - everybody may access all +/proc// directories (default). -hidepid=1 means users may not access any /proc// directories but their -own. Sensitive files like cmdline, sched*, status are now protected against -other users. This makes it impossible to learn whether any user runs -specific program (given the program doesn't reveal itself by its behaviour). -As an additional bonus, as /proc//cmdline is unaccessible for other users, -poorly written programs passing sensitive information via program arguments are -now protected against local eavesdroppers. +hidepid=noaccess or hidepid=1 means users may not access any /proc// +directories but their own. Sensitive files like cmdline, sched*, status are now +protected against other users. This makes it impossible to learn whether any +user runs specific program (given the program doesn't reveal itself by its +behaviour). As an additional bonus, as /proc//cmdline is unaccessible for +other users, poorly written programs passing sensitive information via program +arguments are now protected against local eavesdroppers. -hidepid=2 means hidepid=1 plus all /proc// will be fully invisible to other -users. It doesn't mean that it hides a fact whether a process with a specific -pid value exists (it can be learned by other means, e.g. by "kill -0 $PID"), -but it hides process' uid and gid, which may be learned by stat()'ing -/proc// otherwise. It greatly complicates an intruder's task of gathering -information about running processes, whether some daemon runs with elevated -privileges, whether other user runs some sensitive program, whether other users -run any program at all, etc. +hidepid=invisible or hidepid=2 means hidepid=1 plus all /proc// will be +fully invisible to other users. It doesn't mean that it hides a fact whether a +process with a specific pid value exists (it can be learned by other means, e.g. +by "kill -0 $PID"), but it hides process' uid and gid, which may be learned by +stat()'ing /proc// otherwise. It greatly complicates an intruder's task of +gathering information about running processes, whether some daemon runs with +elevated privileges, whether other user runs some sensitive program, whether +other users run any program at all, etc. + +hidepid=ptraceable or hidepid=4 means that procfs should only contain +/proc// directories that the caller can ptrace. gid= defines a group authorized to learn processes information otherwise prohibited by hidepid=. If you use some daemon like identd which needs to learn information about processes information, just add identd to this group. + +subset=pid hides all top level files and directories in the procfs that +are not related to tasks. + +5 Filesystem behavior +---------------------------- + +Originally, before the advent of pid namepsace, procfs was a global file +system. It means that there was only one procfs instance in the system. + +When pid namespace was added, a separate procfs instance was mounted in +each pid namespace. So, procfs mount options are global among all +mountpoints within the same namespace. + +:: + +# grep ^proc /proc/mounts +proc /proc proc rw,relatime,hidepid=2 0 0 + +# strace -e mount mount -o hidepid=1 -t proc proc /tmp/proc +mount("proc", "/tmp/proc", "proc", 0, "hidepid=1") = 0 ++++ exited with 0 +++ + +# grep ^proc /proc/mounts +proc /proc proc rw,relatime,hidepid=2 0 0 +proc /tmp/proc proc rw,relatime,hidepid=2 0 0 + +and only after remounting procfs mount options will change at all +mountpoints. + +# mount -o remount,hidepid=1 -t proc proc /tmp/proc + +# grep ^proc /proc/mounts +proc /proc proc rw,relatime,hidepid=1 0 0 +proc /tmp/proc proc rw,relatime,hidepid=1 0 0 + +This behavior is different from the behavior of other filesystems. + +The new procfs behavior is more like other filesystems. Each procfs mount +creates a new procfs instance. Mount options affect own procfs instance. +It means that it became possible to have several procfs instances +displaying tasks with different filtering options in one pid namespace. + +# mount -o hidepid=invisible -t proc proc /proc +# mount -o hidepid=noaccess -t proc proc /tmp/proc +# grep ^proc /proc/mounts +proc /proc proc rw,relatime,hidepid=invisible 0 0 +proc /tmp/proc proc rw,relatime,hidepid=noaccess 0 0 diff --git a/fs/exec.c b/fs/exec.c index 2c465119affc..2f0a74582ac9 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1176,7 +1176,6 @@ static int de_thread(struct task_struct *tsk) tsk->start_boottime = leader->start_boottime; BUG_ON(!same_thread_group(leader, tsk)); - BUG_ON(has_group_leader_pid(tsk)); /* * An exec() starts a new thread group with the * TGID of the previous thread group. Rehash the @@ -1186,11 +1185,8 @@ static int de_thread(struct task_struct *tsk) /* Become a process group leader with the old leader's pid. * The old leader becomes a thread of the this thread group. - * Note: The old leader also uses this pid until release_task - * is called. Odd but simple and correct. */ - tsk->pid = leader->pid; - change_pid(tsk, PIDTYPE_PID, task_pid(leader)); + exchange_tids(tsk, leader); transfer_pid(leader, tsk, PIDTYPE_TGID); transfer_pid(leader, tsk, PIDTYPE_PGID); transfer_pid(leader, tsk, PIDTYPE_SID); diff --git a/fs/locks.c b/fs/locks.c index 1d4f4d5da704..6fd1f6e83178 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2823,7 +2823,7 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, { struct inode *inode = NULL; unsigned int fl_pid; - struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; + struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); fl_pid = locks_translate_pid(fl, proc_pidns); /* @@ -2901,7 +2901,7 @@ static int locks_show(struct seq_file *f, void *v) { struct locks_iterator *iter = f->private; struct file_lock *fl, *bfl; - struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; + struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); fl = hlist_entry(v, struct file_lock, fl_link); diff --git a/fs/proc/array.c b/fs/proc/array.c index 8e16f14bb05a..043311014db2 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -728,7 +728,7 @@ static int children_seq_show(struct seq_file *seq, void *v) { struct inode *inode = file_inode(seq->file); - seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode))); + seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode->i_sb))); return 0; } diff --git a/fs/proc/base.c b/fs/proc/base.c index eb2255e95f62..b1d94d14ed5a 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -697,13 +697,21 @@ int proc_setattr(struct dentry *dentry, struct iattr *attr) * May current process learn task's sched/cmdline info (for hide_pid_min=1) * or euid/egid (for hide_pid_min=2)? */ -static bool has_pid_permissions(struct pid_namespace *pid, +static bool has_pid_permissions(struct proc_fs_info *fs_info, struct task_struct *task, - int hide_pid_min) + enum proc_hidepid hide_pid_min) { - if (pid->hide_pid < hide_pid_min) + /* + * If 'hidpid' mount option is set force a ptrace check, + * we indicate that we are using a filesystem syscall + * by passing PTRACE_MODE_READ_FSCREDS + */ + if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) + return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); + + if (fs_info->hide_pid < hide_pid_min) return true; - if (in_group_p(pid->pid_gid)) + if (in_group_p(fs_info->pid_gid)) return true; return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); } @@ -711,18 +719,18 @@ static bool has_pid_permissions(struct pid_namespace *pid, static int proc_pid_permission(struct inode *inode, int mask) { - struct pid_namespace *pid = proc_pid_ns(inode); + struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb); struct task_struct *task; bool has_perms; task = get_proc_task(inode); if (!task) return -ESRCH; - has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS); + has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS); put_task_struct(task); if (!has_perms) { - if (pid->hide_pid == HIDEPID_INVISIBLE) { + if (fs_info->hide_pid == HIDEPID_INVISIBLE) { /* * Let's make getdents(), stat(), and open() * consistent with each other. If a process @@ -746,7 +754,7 @@ static const struct inode_operations proc_def_inode_operations = { static int proc_single_show(struct seq_file *m, void *v) { struct inode *inode = m->private; - struct pid_namespace *ns = proc_pid_ns(inode); + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); struct pid *pid = proc_pid(inode); struct task_struct *task; int ret; @@ -1415,7 +1423,7 @@ static const struct file_operations proc_fail_nth_operations = { static int sched_show(struct seq_file *m, void *v) { struct inode *inode = m->private; - struct pid_namespace *ns = proc_pid_ns(inode); + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); struct task_struct *p; p = get_proc_task(inode); @@ -1909,7 +1917,7 @@ int pid_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { struct inode *inode = d_inode(path->dentry); - struct pid_namespace *pid = proc_pid_ns(inode); + struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb); struct task_struct *task; generic_fillattr(inode, stat); @@ -1919,7 +1927,7 @@ int pid_getattr(const struct path *path, struct kstat *stat, rcu_read_lock(); task = pid_task(proc_pid(inode), PIDTYPE_PID); if (task) { - if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) { + if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) { rcu_read_unlock(); /* * This doesn't prevent learning whether PID exists, @@ -2470,7 +2478,7 @@ static int proc_timers_open(struct inode *inode, struct file *file) return -ENOMEM; tp->pid = proc_pid(inode); - tp->ns = proc_pid_ns(inode); + tp->ns = proc_pid_ns(inode->i_sb); return 0; } @@ -3312,6 +3320,7 @@ struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags) { struct task_struct *task; unsigned tgid; + struct proc_fs_info *fs_info; struct pid_namespace *ns; struct dentry *result = ERR_PTR(-ENOENT); @@ -3319,7 +3328,8 @@ struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags) if (tgid == ~0U) goto out; - ns = dentry->d_sb->s_fs_info; + fs_info = proc_sb_info(dentry->d_sb); + ns = fs_info->pid_ns; rcu_read_lock(); task = find_task_by_pid_ns(tgid, ns); if (task) @@ -3328,7 +3338,14 @@ struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags) if (!task) goto out; + /* Limit procfs to only ptraceable tasks */ + if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) { + if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS)) + goto out_put_task; + } + result = proc_pid_instantiate(dentry, task, NULL); +out_put_task: put_task_struct(task); out: return result; @@ -3354,20 +3371,8 @@ retry: pid = find_ge_pid(iter.tgid, ns); if (pid) { iter.tgid = pid_nr_ns(pid, ns); - iter.task = pid_task(pid, PIDTYPE_PID); - /* What we to know is if the pid we have find is the - * pid of a thread_group_leader. Testing for task - * being a thread_group_leader is the obvious thing - * todo but there is a window when it fails, due to - * the pid transfer logic in de_thread. - * - * So we perform the straight forward test of seeing - * if the pid we have found is the pid of a thread - * group leader, and don't worry if the task we have - * found doesn't happen to be a thread group leader. - * As we don't care in the case of readdir. - */ - if (!iter.task || !has_group_leader_pid(iter.task)) { + iter.task = pid_task(pid, PIDTYPE_TGID); + if (!iter.task) { iter.tgid += 1; goto retry; } @@ -3383,20 +3388,21 @@ retry: int proc_pid_readdir(struct file *file, struct dir_context *ctx) { struct tgid_iter iter; - struct pid_namespace *ns = proc_pid_ns(file_inode(file)); + struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb); + struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb); loff_t pos = ctx->pos; if (pos >= PID_MAX_LIMIT + TGID_OFFSET) return 0; if (pos == TGID_OFFSET - 2) { - struct inode *inode = d_inode(ns->proc_self); + struct inode *inode = d_inode(fs_info->proc_self); if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK)) return 0; ctx->pos = pos = pos + 1; } if (pos == TGID_OFFSET - 1) { - struct inode *inode = d_inode(ns->proc_thread_self); + struct inode *inode = d_inode(fs_info->proc_thread_self); if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK)) return 0; ctx->pos = pos = pos + 1; @@ -3410,7 +3416,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) unsigned int len; cond_resched(); - if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE)) + if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE)) continue; len = snprintf(name, sizeof(name), "%u", iter.tgid); @@ -3610,6 +3616,7 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry struct task_struct *task; struct task_struct *leader = get_proc_task(dir); unsigned tid; + struct proc_fs_info *fs_info; struct pid_namespace *ns; struct dentry *result = ERR_PTR(-ENOENT); @@ -3620,7 +3627,8 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry if (tid == ~0U) goto out; - ns = dentry->d_sb->s_fs_info; + fs_info = proc_sb_info(dentry->d_sb); + ns = fs_info->pid_ns; rcu_read_lock(); task = find_task_by_pid_ns(tid, ns); if (task) @@ -3734,7 +3742,7 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx) /* f_version caches the tgid value that the last readdir call couldn't * return. lseek aka telldir automagically resets f_version to 0. */ - ns = proc_pid_ns(inode); + ns = proc_pid_ns(inode->i_sb); tid = (int)file->f_version; file->f_version = 0; for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 4ed6dabdf6ff..2f9fa179194d 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -269,6 +269,11 @@ struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry, struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { + struct proc_fs_info *fs_info = proc_sb_info(dir->i_sb); + + if (fs_info->pidonly == PROC_PIDONLY_ON) + return ERR_PTR(-ENOENT); + return proc_lookup_de(dir, dentry, PDE(dir)); } @@ -325,6 +330,10 @@ int proc_readdir_de(struct file *file, struct dir_context *ctx, int proc_readdir(struct file *file, struct dir_context *ctx) { struct inode *inode = file_inode(file); + struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb); + + if (fs_info->pidonly == PROC_PIDONLY_ON) + return 1; return proc_readdir_de(file, ctx, PDE(inode)); } diff --git a/fs/proc/inode.c b/fs/proc/inode.c index fb4cace9ea41..f40c2532c057 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -24,6 +24,7 @@ #include #include #include +#include #include @@ -165,15 +166,28 @@ void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock deactivate_super(old_sb); } +static inline const char *hidepid2str(enum proc_hidepid v) +{ + switch (v) { + case HIDEPID_OFF: return "off"; + case HIDEPID_NO_ACCESS: return "noaccess"; + case HIDEPID_INVISIBLE: return "invisible"; + case HIDEPID_NOT_PTRACEABLE: return "ptraceable"; + } + WARN_ONCE(1, "bad hide_pid value: %d\n", v); + return "unknown"; +} + static int proc_show_options(struct seq_file *seq, struct dentry *root) { - struct super_block *sb = root->d_sb; - struct pid_namespace *pid = sb->s_fs_info; + struct proc_fs_info *fs_info = proc_sb_info(root->d_sb); - if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID)) - seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid)); - if (pid->hide_pid != HIDEPID_OFF) - seq_printf(seq, ",hidepid=%u", pid->hide_pid); + if (!gid_eq(fs_info->pid_gid, GLOBAL_ROOT_GID)) + seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, fs_info->pid_gid)); + if (fs_info->hide_pid != HIDEPID_OFF) + seq_printf(seq, ",hidepid=%s", hidepid2str(fs_info->hide_pid)); + if (fs_info->pidonly != PROC_PIDONLY_OFF) + seq_printf(seq, ",subset=pid"); return 0; } @@ -464,6 +478,7 @@ proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, static int proc_reg_open(struct inode *inode, struct file *file) { + struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb); struct proc_dir_entry *pde = PDE(inode); int rv = 0; typeof_member(struct proc_ops, proc_open) open; @@ -477,6 +492,9 @@ static int proc_reg_open(struct inode *inode, struct file *file) return rv; } + if (fs_info->pidonly == PROC_PIDONLY_ON) + return -ENOENT; + /* * Ensure that * 1) PDE's ->release hook will be called no matter what diff --git a/fs/proc/root.c b/fs/proc/root.c index cdbe9293ea55..ffebed1999e5 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -32,21 +32,86 @@ struct proc_fs_context { struct pid_namespace *pid_ns; unsigned int mask; - int hidepid; + enum proc_hidepid hidepid; int gid; + enum proc_pidonly pidonly; }; enum proc_param { Opt_gid, Opt_hidepid, + Opt_subset, }; static const struct fs_parameter_spec proc_fs_parameters[] = { fsparam_u32("gid", Opt_gid), - fsparam_u32("hidepid", Opt_hidepid), + fsparam_string("hidepid", Opt_hidepid), + fsparam_string("subset", Opt_subset), {} }; +static inline int valid_hidepid(unsigned int value) +{ + return (value == HIDEPID_OFF || + value == HIDEPID_NO_ACCESS || + value == HIDEPID_INVISIBLE || + value == HIDEPID_NOT_PTRACEABLE); +} + +static int proc_parse_hidepid_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct proc_fs_context *ctx = fc->fs_private; + struct fs_parameter_spec hidepid_u32_spec = fsparam_u32("hidepid", Opt_hidepid); + struct fs_parse_result result; + int base = (unsigned long)hidepid_u32_spec.data; + + if (param->type != fs_value_is_string) + return invalf(fc, "proc: unexpected type of hidepid value\n"); + + if (!kstrtouint(param->string, base, &result.uint_32)) { + if (!valid_hidepid(result.uint_32)) + return invalf(fc, "proc: unknown value of hidepid - %s\n", param->string); + ctx->hidepid = result.uint_32; + return 0; + } + + if (!strcmp(param->string, "off")) + ctx->hidepid = HIDEPID_OFF; + else if (!strcmp(param->string, "noaccess")) + ctx->hidepid = HIDEPID_NO_ACCESS; + else if (!strcmp(param->string, "invisible")) + ctx->hidepid = HIDEPID_INVISIBLE; + else if (!strcmp(param->string, "ptraceable")) + ctx->hidepid = HIDEPID_NOT_PTRACEABLE; + else + return invalf(fc, "proc: unknown value of hidepid - %s\n", param->string); + + return 0; +} + +static int proc_parse_subset_param(struct fs_context *fc, char *value) +{ + struct proc_fs_context *ctx = fc->fs_private; + + while (value) { + char *ptr = strchr(value, ','); + + if (ptr != NULL) + *ptr++ = '\0'; + + if (*value != '\0') { + if (!strcmp(value, "pid")) { + ctx->pidonly = PROC_PIDONLY_ON; + } else { + return invalf(fc, "proc: unsupported subset option - %s\n", value); + } + } + value = ptr; + } + + return 0; +} + static int proc_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct proc_fs_context *ctx = fc->fs_private; @@ -63,10 +128,13 @@ static int proc_parse_param(struct fs_context *fc, struct fs_parameter *param) break; case Opt_hidepid: - ctx->hidepid = result.uint_32; - if (ctx->hidepid < HIDEPID_OFF || - ctx->hidepid > HIDEPID_INVISIBLE) - return invalfc(fc, "hidepid value must be between 0 and 2.\n"); + if (proc_parse_hidepid_param(fc, param)) + return -EINVAL; + break; + + case Opt_subset: + if (proc_parse_subset_param(fc, param->string) < 0) + return -EINVAL; break; default: @@ -77,26 +145,33 @@ static int proc_parse_param(struct fs_context *fc, struct fs_parameter *param) return 0; } -static void proc_apply_options(struct super_block *s, +static void proc_apply_options(struct proc_fs_info *fs_info, struct fs_context *fc, - struct pid_namespace *pid_ns, struct user_namespace *user_ns) { struct proc_fs_context *ctx = fc->fs_private; if (ctx->mask & (1 << Opt_gid)) - pid_ns->pid_gid = make_kgid(user_ns, ctx->gid); + fs_info->pid_gid = make_kgid(user_ns, ctx->gid); if (ctx->mask & (1 << Opt_hidepid)) - pid_ns->hide_pid = ctx->hidepid; + fs_info->hide_pid = ctx->hidepid; + if (ctx->mask & (1 << Opt_subset)) + fs_info->pidonly = ctx->pidonly; } static int proc_fill_super(struct super_block *s, struct fs_context *fc) { - struct pid_namespace *pid_ns = get_pid_ns(s->s_fs_info); + struct proc_fs_context *ctx = fc->fs_private; struct inode *root_inode; + struct proc_fs_info *fs_info; int ret; - proc_apply_options(s, fc, pid_ns, current_user_ns()); + fs_info = kzalloc(sizeof(*fs_info), GFP_KERNEL); + if (!fs_info) + return -ENOMEM; + + fs_info->pid_ns = get_pid_ns(ctx->pid_ns); + proc_apply_options(fs_info, fc, current_user_ns()); /* User space would break if executables or devices appear on proc */ s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV; @@ -106,6 +181,7 @@ static int proc_fill_super(struct super_block *s, struct fs_context *fc) s->s_magic = PROC_SUPER_MAGIC; s->s_op = &proc_sops; s->s_time_gran = 1; + s->s_fs_info = fs_info; /* * procfs isn't actually a stacking filesystem; however, there is @@ -113,7 +189,7 @@ static int proc_fill_super(struct super_block *s, struct fs_context *fc) * top of it */ s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH; - + /* procfs dentries and inodes don't require IO to create */ s->s_shrink.seeks = 0; @@ -140,19 +216,17 @@ static int proc_fill_super(struct super_block *s, struct fs_context *fc) static int proc_reconfigure(struct fs_context *fc) { struct super_block *sb = fc->root->d_sb; - struct pid_namespace *pid = sb->s_fs_info; + struct proc_fs_info *fs_info = proc_sb_info(sb); sync_filesystem(sb); - proc_apply_options(sb, fc, pid, current_user_ns()); + proc_apply_options(fs_info, fc, current_user_ns()); return 0; } static int proc_get_tree(struct fs_context *fc) { - struct proc_fs_context *ctx = fc->fs_private; - - return get_tree_keyed(fc, proc_fill_super, ctx->pid_ns); + return get_tree_nodev(fc, proc_fill_super); } static void proc_fs_context_free(struct fs_context *fc) @@ -188,22 +262,17 @@ static int proc_init_fs_context(struct fs_context *fc) static void proc_kill_sb(struct super_block *sb) { - struct pid_namespace *ns; + struct proc_fs_info *fs_info = proc_sb_info(sb); + + if (fs_info->proc_self) + dput(fs_info->proc_self); + + if (fs_info->proc_thread_self) + dput(fs_info->proc_thread_self); - ns = (struct pid_namespace *)sb->s_fs_info; - if (ns->proc_self) - dput(ns->proc_self); - if (ns->proc_thread_self) - dput(ns->proc_thread_self); kill_anon_super(sb); - - /* Make the pid namespace safe for the next mount of proc */ - ns->proc_self = NULL; - ns->proc_thread_self = NULL; - ns->pid_gid = GLOBAL_ROOT_GID; - ns->hide_pid = 0; - - put_pid_ns(ns); + put_pid_ns(fs_info->pid_ns); + kfree(fs_info); } static struct file_system_type proc_fs_type = { diff --git a/fs/proc/self.c b/fs/proc/self.c index 57c0a1047250..ca5158fa561c 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -12,7 +12,7 @@ static const char *proc_self_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { - struct pid_namespace *ns = proc_pid_ns(inode); + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); pid_t tgid = task_tgid_nr_ns(current, ns); char *name; @@ -36,10 +36,10 @@ static unsigned self_inum __ro_after_init; int proc_setup_self(struct super_block *s) { struct inode *root_inode = d_inode(s->s_root); - struct pid_namespace *ns = proc_pid_ns(root_inode); + struct proc_fs_info *fs_info = proc_sb_info(s); struct dentry *self; int ret = -ENOMEM; - + inode_lock(root_inode); self = d_alloc_name(s->s_root, "self"); if (self) { @@ -62,7 +62,7 @@ int proc_setup_self(struct super_block *s) if (ret) pr_err("proc_fill_super: can't allocate /proc/self\n"); else - ns->proc_self = self; + fs_info->proc_self = self; return ret; } diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c index f61ae53533f5..ac284f409568 100644 --- a/fs/proc/thread_self.c +++ b/fs/proc/thread_self.c @@ -12,7 +12,7 @@ static const char *proc_thread_self_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { - struct pid_namespace *ns = proc_pid_ns(inode); + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); pid_t tgid = task_tgid_nr_ns(current, ns); pid_t pid = task_pid_nr_ns(current, ns); char *name; @@ -36,7 +36,7 @@ static unsigned thread_self_inum __ro_after_init; int proc_setup_thread_self(struct super_block *s) { struct inode *root_inode = d_inode(s->s_root); - struct pid_namespace *ns = proc_pid_ns(root_inode); + struct proc_fs_info *fs_info = proc_sb_info(s); struct dentry *thread_self; int ret = -ENOMEM; @@ -60,9 +60,9 @@ int proc_setup_thread_self(struct super_block *s) inode_unlock(root_inode); if (ret) - pr_err("proc_fill_super: can't allocate /proc/thread_self\n"); + pr_err("proc_fill_super: can't allocate /proc/thread-self\n"); else - ns->proc_thread_self = thread_self; + fs_info->proc_thread_self = thread_self; return ret; } diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c index e4d70c0dffe9..3059a9394c2d 100644 --- a/fs/proc_namespace.c +++ b/fs/proc_namespace.c @@ -37,23 +37,23 @@ static __poll_t mounts_poll(struct file *file, poll_table *wait) return res; } -struct proc_fs_info { +struct proc_fs_opts { int flag; const char *str; }; static int show_sb_opts(struct seq_file *m, struct super_block *sb) { - static const struct proc_fs_info fs_info[] = { + static const struct proc_fs_opts fs_opts[] = { { SB_SYNCHRONOUS, ",sync" }, { SB_DIRSYNC, ",dirsync" }, { SB_MANDLOCK, ",mand" }, { SB_LAZYTIME, ",lazytime" }, { 0, NULL } }; - const struct proc_fs_info *fs_infop; + const struct proc_fs_opts *fs_infop; - for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { + for (fs_infop = fs_opts; fs_infop->flag; fs_infop++) { if (sb->s_flags & fs_infop->flag) seq_puts(m, fs_infop->str); } @@ -63,7 +63,7 @@ static int show_sb_opts(struct seq_file *m, struct super_block *sb) static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt) { - static const struct proc_fs_info mnt_info[] = { + static const struct proc_fs_opts mnt_opts[] = { { MNT_NOSUID, ",nosuid" }, { MNT_NODEV, ",nodev" }, { MNT_NOEXEC, ",noexec" }, @@ -72,9 +72,9 @@ static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt) { MNT_RELATIME, ",relatime" }, { 0, NULL } }; - const struct proc_fs_info *fs_infop; + const struct proc_fs_opts *fs_infop; - for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) { + for (fs_infop = mnt_opts; fs_infop->flag; fs_infop++) { if (mnt->mnt_flags & fs_infop->flag) seq_puts(m, fs_infop->str); } diff --git a/include/linux/pid.h b/include/linux/pid.h index 93543cbc0e6b..176d6cf80e7c 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -102,6 +102,7 @@ extern void attach_pid(struct task_struct *task, enum pid_type); extern void detach_pid(struct task_struct *task, enum pid_type); extern void change_pid(struct task_struct *task, enum pid_type, struct pid *pid); +extern void exchange_tids(struct task_struct *task, struct task_struct *old); extern void transfer_pid(struct task_struct *old, struct task_struct *new, enum pid_type); diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 4956e362e55e..5a5cb45ac57e 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -17,12 +17,6 @@ struct fs_pin; -enum { /* definitions for pid_namespace's hide_pid field */ - HIDEPID_OFF = 0, - HIDEPID_NO_ACCESS = 1, - HIDEPID_INVISIBLE = 2, -}; - struct pid_namespace { struct kref kref; struct idr idr; @@ -32,17 +26,11 @@ struct pid_namespace { struct kmem_cache *pid_cachep; unsigned int level; struct pid_namespace *parent; -#ifdef CONFIG_PROC_FS - struct dentry *proc_self; - struct dentry *proc_thread_self; -#endif #ifdef CONFIG_BSD_PROCESS_ACCT struct fs_pin *bacct; #endif struct user_namespace *user_ns; struct ucounts *ucounts; - kgid_t pid_gid; - int hide_pid; int reboot; /* group exit code if this pidns was rebooted */ struct ns_common ns; } __randomize_layout; diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index ad4ff711fc02..d1eed1b43651 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -42,6 +42,34 @@ struct proc_ops { unsigned long (*proc_get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); } __randomize_layout; +/* definitions for hide_pid field */ +enum proc_hidepid { + HIDEPID_OFF = 0, + HIDEPID_NO_ACCESS = 1, + HIDEPID_INVISIBLE = 2, + HIDEPID_NOT_PTRACEABLE = 4, /* Limit pids to only ptraceable pids */ +}; + +/* definitions for proc mount option pidonly */ +enum proc_pidonly { + PROC_PIDONLY_OFF = 0, + PROC_PIDONLY_ON = 1, +}; + +struct proc_fs_info { + struct pid_namespace *pid_ns; + struct dentry *proc_self; /* For /proc/self */ + struct dentry *proc_thread_self; /* For /proc/thread-self */ + kgid_t pid_gid; + enum proc_hidepid hide_pid; + enum proc_pidonly pidonly; +}; + +static inline struct proc_fs_info *proc_sb_info(struct super_block *sb) +{ + return sb->s_fs_info; +} + #ifdef CONFIG_PROC_FS typedef int (*proc_write_t)(struct file *, char *, size_t); @@ -177,9 +205,9 @@ int open_related_ns(struct ns_common *ns, struct ns_common *(*get_ns)(struct ns_common *ns)); /* get the associated pid namespace for a file in procfs */ -static inline struct pid_namespace *proc_pid_ns(const struct inode *inode) +static inline struct pid_namespace *proc_pid_ns(struct super_block *sb) { - return inode->i_sb->s_fs_info; + return proc_sb_info(sb)->pid_ns; } bool proc_ns_file(const struct file *file); diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 7375bb3da140..df587d181844 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -506,6 +506,27 @@ static inline void hlist_replace_rcu(struct hlist_node *old, WRITE_ONCE(old->pprev, LIST_POISON2); } +/** + * hlists_swap_heads_rcu - swap the lists the hlist heads point to + * @left: The hlist head on the left + * @right: The hlist head on the right + * + * The lists start out as [@left ][node1 ... ] and + [@right ][node2 ... ] + * The lists end up as [@left ][node2 ... ] + * [@right ][node1 ... ] + */ +static inline void hlists_swap_heads_rcu(struct hlist_head *left, struct hlist_head *right) +{ + struct hlist_node *node1 = left->first; + struct hlist_node *node2 = right->first; + + rcu_assign_pointer(left->first, node2); + rcu_assign_pointer(right->first, node1); + WRITE_ONCE(node2->pprev, &left->first); + WRITE_ONCE(node1->pprev, &right->first); +} + /* * return the first or the next element in an RCU protected hlist */ diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 3e5b090c16d4..0ee5e696c5d8 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -654,17 +654,6 @@ static inline bool thread_group_leader(struct task_struct *p) return p->exit_signal >= 0; } -/* Do to the insanities of de_thread it is possible for a process - * to have the pid of the thread group leader without actually being - * the thread group leader. For iteration through the pids in proc - * all we care about is that we have a task with the appropriate - * pid, we don't actually care if we have the right task. - */ -static inline bool has_group_leader_pid(struct task_struct *p) -{ - return task_pid(p) == task_tgid(p); -} - static inline bool same_thread_group(struct task_struct *p1, struct task_struct *p2) { diff --git a/kernel/fork.c b/kernel/fork.c index be98e94cb3cc..cefe8745c46e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1759,7 +1759,7 @@ static void pidfd_show_fdinfo(struct seq_file *m, struct file *f) pid_t nr = -1; if (likely(pid_has_task(pid, PIDTYPE_PID))) { - ns = proc_pid_ns(file_inode(m->file)); + ns = proc_pid_ns(file_inode(m->file)->i_sb); nr = pid_nr_ns(pid, ns); } diff --git a/kernel/pid.c b/kernel/pid.c index c835b844aca7..f1496b757162 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -363,6 +363,25 @@ void change_pid(struct task_struct *task, enum pid_type type, attach_pid(task, type); } +void exchange_tids(struct task_struct *left, struct task_struct *right) +{ + struct pid *pid1 = left->thread_pid; + struct pid *pid2 = right->thread_pid; + struct hlist_head *head1 = &pid1->tasks[PIDTYPE_PID]; + struct hlist_head *head2 = &pid2->tasks[PIDTYPE_PID]; + + /* Swap the single entry tid lists */ + hlists_swap_heads_rcu(head1, head2); + + /* Swap the per task_struct pid */ + rcu_assign_pointer(left->thread_pid, pid2); + rcu_assign_pointer(right->thread_pid, pid1); + + /* Swap the cached value */ + WRITE_ONCE(left->pid, pid_nr(pid2)); + WRITE_ONCE(right->pid, pid_nr(pid1)); +} + /* transfer_pid is an optimization of attach_pid(new), detach_pid(old) */ void transfer_pid(struct task_struct *old, struct task_struct *new, enum pid_type type) @@ -476,8 +495,7 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, rcu_read_lock(); if (!ns) ns = task_active_pid_ns(current); - if (likely(pid_alive(task))) - nr = pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns); + nr = pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns); rcu_read_unlock(); return nr; diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 2fd3b3fa68bf..165117996ea0 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -47,85 +47,65 @@ void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new) /* * Functions for validating access to tasks. */ -static struct task_struct *lookup_task(const pid_t pid, bool thread, - bool gettime) +static struct pid *pid_for_clock(const clockid_t clock, bool gettime) { - struct task_struct *p; + const bool thread = !!CPUCLOCK_PERTHREAD(clock); + const pid_t upid = CPUCLOCK_PID(clock); + struct pid *pid; + + if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX) + return NULL; /* * If the encoded PID is 0, then the timer is targeted at current * or the process to which current belongs. */ + if (upid == 0) + return thread ? task_pid(current) : task_tgid(current); + + pid = find_vpid(upid); if (!pid) - return thread ? current : current->group_leader; + return NULL; - p = find_task_by_vpid(pid); - if (!p) - return p; - - if (thread) - return same_thread_group(p, current) ? p : NULL; - - if (gettime) { - /* - * For clock_gettime(PROCESS) the task does not need to be - * the actual group leader. tsk->sighand gives - * access to the group's clock. - * - * Timers need the group leader because they take a - * reference on it and store the task pointer until the - * timer is destroyed. - */ - return (p == current || thread_group_leader(p)) ? p : NULL; + if (thread) { + struct task_struct *tsk = pid_task(pid, PIDTYPE_PID); + return (tsk && same_thread_group(tsk, current)) ? pid : NULL; } /* - * For processes require that p is group leader. + * For clock_gettime(PROCESS) allow finding the process by + * with the pid of the current task. The code needs the tgid + * of the process so that pid_task(pid, PIDTYPE_TGID) can be + * used to find the process. */ - return has_group_leader_pid(p) ? p : NULL; -} + if (gettime && (pid == task_pid(current))) + return task_tgid(current); -static struct task_struct *__get_task_for_clock(const clockid_t clock, - bool getref, bool gettime) -{ - const bool thread = !!CPUCLOCK_PERTHREAD(clock); - const pid_t pid = CPUCLOCK_PID(clock); - struct task_struct *p; - - if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX) - return NULL; - - rcu_read_lock(); - p = lookup_task(pid, thread, gettime); - if (p && getref) - get_task_struct(p); - rcu_read_unlock(); - return p; -} - -static inline struct task_struct *get_task_for_clock(const clockid_t clock) -{ - return __get_task_for_clock(clock, true, false); -} - -static inline struct task_struct *get_task_for_clock_get(const clockid_t clock) -{ - return __get_task_for_clock(clock, true, true); + /* + * For processes require that pid identifies a process. + */ + return pid_has_task(pid, PIDTYPE_TGID) ? pid : NULL; } static inline int validate_clock_permissions(const clockid_t clock) { - return __get_task_for_clock(clock, false, false) ? 0 : -EINVAL; + int ret; + + rcu_read_lock(); + ret = pid_for_clock(clock, false) ? 0 : -EINVAL; + rcu_read_unlock(); + + return ret; } -static inline enum pid_type cpu_timer_pid_type(struct k_itimer *timer) +static inline enum pid_type clock_pid_type(const clockid_t clock) { - return CPUCLOCK_PERTHREAD(timer->it_clock) ? PIDTYPE_PID : PIDTYPE_TGID; + return CPUCLOCK_PERTHREAD(clock) ? PIDTYPE_PID : PIDTYPE_TGID; } static inline struct task_struct *cpu_timer_task_rcu(struct k_itimer *timer) { - return pid_task(timer->it.cpu.pid, cpu_timer_pid_type(timer)); + return pid_task(timer->it.cpu.pid, clock_pid_type(timer->it_clock)); } /* @@ -373,15 +353,18 @@ static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp) struct task_struct *tsk; u64 t; - tsk = get_task_for_clock_get(clock); - if (!tsk) + rcu_read_lock(); + tsk = pid_task(pid_for_clock(clock, true), clock_pid_type(clock)); + if (!tsk) { + rcu_read_unlock(); return -EINVAL; + } if (CPUCLOCK_PERTHREAD(clock)) t = cpu_clock_sample(clkid, tsk); else t = cpu_clock_sample_group(clkid, tsk, false); - put_task_struct(tsk); + rcu_read_unlock(); *tp = ns_to_timespec64(t); return 0; @@ -394,19 +377,19 @@ static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp) */ static int posix_cpu_timer_create(struct k_itimer *new_timer) { - struct task_struct *p = get_task_for_clock(new_timer->it_clock); + struct pid *pid; - if (!p) + rcu_read_lock(); + pid = pid_for_clock(new_timer->it_clock, false); + if (!pid) { + rcu_read_unlock(); return -EINVAL; + } new_timer->kclock = &clock_posix_cpu; timerqueue_init(&new_timer->it.cpu.node); - new_timer->it.cpu.pid = get_task_pid(p, cpu_timer_pid_type(new_timer)); - /* - * get_task_for_clock() took a reference on @p. Drop it as the timer - * holds a reference on the pid of @p. - */ - put_task_struct(p); + new_timer->it.cpu.pid = get_pid(pid); + rcu_read_unlock(); return 0; } diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c index d64b83e85642..ce4fbba4acce 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -779,7 +779,7 @@ static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos) { struct ip6fl_iter_state *state = ip6fl_seq_private(seq); - state->pid_ns = proc_pid_ns(file_inode(seq->file)); + state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb); rcu_read_lock_bh(); return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c index bf38fc1b59b2..df4798980416 100644 --- a/security/tomoyo/realpath.c +++ b/security/tomoyo/realpath.c @@ -7,6 +7,7 @@ #include "common.h" #include +#include /** * tomoyo_encode2 - Encode binary string to ascii string. @@ -161,9 +162,10 @@ static char *tomoyo_get_local_path(struct dentry *dentry, char * const buffer, if (sb->s_magic == PROC_SUPER_MAGIC && *pos == '/') { char *ep; const pid_t pid = (pid_t) simple_strtoul(pos + 1, &ep, 10); + struct pid_namespace *proc_pidns = proc_pid_ns(sb); if (*ep == '/' && pid && pid == - task_tgid_nr_ns(current, sb->s_fs_info)) { + task_tgid_nr_ns(current, proc_pidns)) { pos = ep - 5; if (pos < buffer) goto out; diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore index 4bca5a9327a4..bed4b5318a86 100644 --- a/tools/testing/selftests/proc/.gitignore +++ b/tools/testing/selftests/proc/.gitignore @@ -2,7 +2,9 @@ /fd-001-lookup /fd-002-posix-eq /fd-003-kthread +/proc-fsconfig-hidepid /proc-loadavg-001 +/proc-multiple-procfs /proc-pid-vm /proc-self-map-files-001 /proc-self-map-files-002 diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile index a8ed0f684829..8be8a03d2973 100644 --- a/tools/testing/selftests/proc/Makefile +++ b/tools/testing/selftests/proc/Makefile @@ -19,5 +19,7 @@ TEST_GEN_PROGS += self TEST_GEN_PROGS += setns-dcache TEST_GEN_PROGS += setns-sysvipc TEST_GEN_PROGS += thread-self +TEST_GEN_PROGS += proc-multiple-procfs +TEST_GEN_PROGS += proc-fsconfig-hidepid include ../lib.mk diff --git a/tools/testing/selftests/proc/proc-fsconfig-hidepid.c b/tools/testing/selftests/proc/proc-fsconfig-hidepid.c new file mode 100644 index 000000000000..b9af8f537185 --- /dev/null +++ b/tools/testing/selftests/proc/proc-fsconfig-hidepid.c @@ -0,0 +1,50 @@ +/* + * Copyright © 2020 Alexey Gladkov + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +#include +#include +#include +#include +#include +#include + +static inline int fsopen(const char *fsname, unsigned int flags) +{ + return syscall(__NR_fsopen, fsname, flags); +} + +static inline int fsconfig(int fd, unsigned int cmd, const char *key, const void *val, int aux) +{ + return syscall(__NR_fsconfig, fd, cmd, key, val, aux); +} + +int main(void) +{ + int fsfd, ret; + int hidepid = 2; + + assert((fsfd = fsopen("proc", 0)) != -1); + + ret = fsconfig(fsfd, FSCONFIG_SET_BINARY, "hidepid", &hidepid, 0); + assert(ret == -1); + assert(errno == EINVAL); + + assert(!fsconfig(fsfd, FSCONFIG_SET_STRING, "hidepid", "2", 0)); + assert(!fsconfig(fsfd, FSCONFIG_SET_STRING, "hidepid", "invisible", 0)); + + assert(!close(fsfd)); + + return 0; +} diff --git a/tools/testing/selftests/proc/proc-multiple-procfs.c b/tools/testing/selftests/proc/proc-multiple-procfs.c new file mode 100644 index 000000000000..ab912ad95dab --- /dev/null +++ b/tools/testing/selftests/proc/proc-multiple-procfs.c @@ -0,0 +1,48 @@ +/* + * Copyright © 2020 Alexey Gladkov + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +#include +#include +#include +#include +#include +#include + +int main(void) +{ + struct stat proc_st1, proc_st2; + char procbuff[] = "/tmp/proc.XXXXXX/meminfo"; + char procdir1[] = "/tmp/proc.XXXXXX"; + char procdir2[] = "/tmp/proc.XXXXXX"; + + assert(mkdtemp(procdir1) != NULL); + assert(mkdtemp(procdir2) != NULL); + + assert(!mount("proc", procdir1, "proc", 0, "hidepid=1")); + assert(!mount("proc", procdir2, "proc", 0, "hidepid=2")); + + snprintf(procbuff, sizeof(procbuff), "%s/meminfo", procdir1); + assert(!stat(procbuff, &proc_st1)); + + snprintf(procbuff, sizeof(procbuff), "%s/meminfo", procdir2); + assert(!stat(procbuff, &proc_st2)); + + umount(procdir1); + umount(procdir2); + + assert(proc_st1.st_dev != proc_st2.st_dev); + + return 0; +}