diff options
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 56 |
1 files changed, 40 insertions, 16 deletions
diff --git a/fs/exec.c b/fs/exec.c index 4e497b9ee71e..65145a3df065 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -19,7 +19,7 @@ * current->executable is only used by the procfs. This allows a dispatch * table to check for several different types of binary formats. We keep * trying until we recognize the file or we run out of supported binary - * formats. + * formats. */ #include <linux/slab.h> @@ -32,6 +32,11 @@ #include <linux/swap.h> #include <linux/string.h> #include <linux/init.h> +#include <linux/sched/mm.h> +#include <linux/sched/coredump.h> +#include <linux/sched/signal.h> +#include <linux/sched/numa_balancing.h> +#include <linux/sched/task.h> #include <linux/pagemap.h> #include <linux/perf_event.h> #include <linux/highmem.h> @@ -58,7 +63,7 @@ #include <linux/compat.h> #include <linux/vmalloc.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> #include <asm/mmu_context.h> #include <asm/tlb.h> @@ -209,7 +214,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, * doing the exec and bprm->mm is the new process's mm. */ ret = get_user_pages_remote(current, bprm->mm, pos, 1, gup_flags, - &page, NULL); + &page, NULL, NULL); if (ret <= 0) return NULL; @@ -1088,7 +1093,7 @@ static int de_thread(struct task_struct *tsk) struct task_struct *leader = tsk->group_leader; for (;;) { - threadgroup_change_begin(tsk); + cgroup_threadgroup_change_begin(tsk); write_lock_irq(&tasklist_lock); /* * Do this under tasklist_lock to ensure that @@ -1099,7 +1104,7 @@ static int de_thread(struct task_struct *tsk) break; __set_current_state(TASK_KILLABLE); write_unlock_irq(&tasklist_lock); - threadgroup_change_end(tsk); + cgroup_threadgroup_change_end(tsk); schedule(); if (unlikely(__fatal_signal_pending(tsk))) goto killed; @@ -1157,7 +1162,7 @@ static int de_thread(struct task_struct *tsk) if (unlikely(leader->ptrace)) __wake_up_parent(leader, leader->parent); write_unlock_irq(&tasklist_lock); - threadgroup_change_end(tsk); + cgroup_threadgroup_change_end(tsk); release_task(leader); } @@ -1169,8 +1174,10 @@ no_thread_group: /* we have changed execution domain */ tsk->exit_signal = SIGCHLD; +#ifdef CONFIG_POSIX_TIMERS exit_itimers(sig); flush_itimer_signals(); +#endif if (atomic_read(&oldsighand->count) != 1) { struct sighand_struct *newsighand; @@ -1266,6 +1273,13 @@ int flush_old_exec(struct linux_binprm * bprm) flush_thread(); current->personality &= ~bprm->per_clear; + /* + * We have to apply CLOEXEC before we change whether the process is + * dumpable (in setup_new_exec) to avoid a race with a process in userspace + * trying to access the should-be-closed file descriptors of a process + * undergoing exec(2). + */ + do_close_on_exec(current->files); return 0; out: @@ -1275,8 +1289,22 @@ EXPORT_SYMBOL(flush_old_exec); void would_dump(struct linux_binprm *bprm, struct file *file) { - if (inode_permission(file_inode(file), MAY_READ) < 0) + struct inode *inode = file_inode(file); + if (inode_permission(inode, MAY_READ) < 0) { + struct user_namespace *old, *user_ns; bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; + + /* Ensure mm->user_ns contains the executable */ + user_ns = old = bprm->mm->user_ns; + while ((user_ns != &init_user_ns) && + !privileged_wrt_inode_uidgid(user_ns, inode)) + user_ns = user_ns->parent; + + if (old != user_ns) { + bprm->mm->user_ns = get_user_ns(user_ns); + put_user_ns(old); + } + } } EXPORT_SYMBOL(would_dump); @@ -1306,7 +1334,6 @@ void setup_new_exec(struct linux_binprm * bprm) !gid_eq(bprm->cred->gid, current_egid())) { current->pdeath_signal = 0; } else { - would_dump(bprm, bprm->file); if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) set_dumpable(current->mm, suid_dumpable); } @@ -1315,7 +1342,6 @@ void setup_new_exec(struct linux_binprm * bprm) group */ current->self_exec_id++; flush_signal_handlers(current, 0); - do_close_on_exec(current->files); } EXPORT_SYMBOL(setup_new_exec); @@ -1405,12 +1431,8 @@ static void check_unsafe_exec(struct linux_binprm *bprm) struct task_struct *p = current, *t; unsigned n_fs; - if (p->ptrace) { - if (p->ptrace & PT_PTRACE_CAP) - bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP; - else - bprm->unsafe |= LSM_UNSAFE_PTRACE; - } + if (p->ptrace) + bprm->unsafe |= LSM_UNSAFE_PTRACE; /* * This isn't strictly necessary, but it makes it harder for LSMs to @@ -1458,7 +1480,7 @@ static void bprm_fill_uid(struct linux_binprm *bprm) if (task_no_new_privs(current)) return; - inode = file_inode(bprm->file); + inode = bprm->file->f_path.dentry->d_inode; mode = READ_ONCE(inode->i_mode); if (!(mode & (S_ISUID|S_ISGID))) return; @@ -1741,6 +1763,8 @@ static int do_execveat_common(int fd, struct filename *filename, if (retval < 0) goto out; + would_dump(bprm, bprm->file); + retval = exec_binprm(bprm); if (retval < 0) goto out; |