summaryrefslogtreecommitdiffstats
path: root/fs/exec.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/exec.c')
-rw-r--r--fs/exec.c165
1 files changed, 46 insertions, 119 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 7ea097f6b341..3d78fccdd723 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -62,7 +62,6 @@
#include <trace/events/task.h>
#include "internal.h"
-#include "coredump.h"
#include <trace/events/sched.h>
@@ -749,11 +748,10 @@ EXPORT_SYMBOL(setup_arg_pages);
#endif /* CONFIG_MMU */
-struct file *open_exec(const char *name)
+static struct file *do_open_exec(struct filename *name)
{
struct file *file;
int err;
- struct filename tmp = { .name = name };
static const struct open_flags open_exec_flags = {
.open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
.acc_mode = MAY_EXEC | MAY_OPEN,
@@ -761,7 +759,7 @@ struct file *open_exec(const char *name)
.lookup_flags = LOOKUP_FOLLOW,
};
- file = do_filp_open(AT_FDCWD, &tmp, &open_exec_flags);
+ file = do_filp_open(AT_FDCWD, name, &open_exec_flags);
if (IS_ERR(file))
goto out;
@@ -785,6 +783,12 @@ exit:
fput(file);
return ERR_PTR(err);
}
+
+struct file *open_exec(const char *name)
+{
+ struct filename tmp = { .name = name };
+ return do_open_exec(&tmp);
+}
EXPORT_SYMBOL(open_exec);
int kernel_read(struct file *file, loff_t offset,
@@ -843,7 +847,6 @@ static int exec_mmap(struct mm_struct *mm)
tsk->active_mm = mm;
activate_mm(active_mm, mm);
task_unlock(tsk);
- arch_pick_mmap_layout(mm);
if (old_mm) {
up_read(&old_mm->mmap_sem);
BUG_ON(active_mm != old_mm);
@@ -1088,8 +1091,8 @@ int flush_old_exec(struct linux_binprm * bprm)
bprm->mm = NULL; /* We're using it now */
set_fs(USER_DS);
- current->flags &=
- ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | PF_NOFREEZE);
+ current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
+ PF_NOFREEZE | PF_NO_SETAFFINITY);
flush_thread();
current->personality &= ~bprm->per_clear;
@@ -1139,9 +1142,7 @@ void setup_new_exec(struct linux_binprm * bprm)
/* An exec changes our domain. We are no longer part of the thread
group */
-
current->self_exec_id++;
-
flush_signal_handlers(current, 0);
do_close_on_exec(current->files);
}
@@ -1166,13 +1167,17 @@ int prepare_bprm_creds(struct linux_binprm *bprm)
return -ENOMEM;
}
-void free_bprm(struct linux_binprm *bprm)
+static void free_bprm(struct linux_binprm *bprm)
{
free_arg_pages(bprm);
if (bprm->cred) {
mutex_unlock(&current->signal->cred_guard_mutex);
abort_creds(bprm->cred);
}
+ if (bprm->file) {
+ allow_write_access(bprm->file);
+ fput(bprm->file);
+ }
/* If a binfmt changed the interp, free it. */
if (bprm->interp != bprm->filename)
kfree(bprm->interp);
@@ -1224,11 +1229,10 @@ EXPORT_SYMBOL(install_exec_creds);
* - the caller must hold ->cred_guard_mutex to protect against
* PTRACE_ATTACH
*/
-static int check_unsafe_exec(struct linux_binprm *bprm)
+static void check_unsafe_exec(struct linux_binprm *bprm)
{
struct task_struct *p = current, *t;
unsigned n_fs;
- int res = 0;
if (p->ptrace) {
if (p->ptrace & PT_PTRACE_CAP)
@@ -1244,31 +1248,25 @@ static int check_unsafe_exec(struct linux_binprm *bprm)
if (current->no_new_privs)
bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;
+ t = p;
n_fs = 1;
spin_lock(&p->fs->lock);
rcu_read_lock();
- for (t = next_thread(p); t != p; t = next_thread(t)) {
+ while_each_thread(p, t) {
if (t->fs == p->fs)
n_fs++;
}
rcu_read_unlock();
- if (p->fs->users > n_fs) {
+ if (p->fs->users > n_fs)
bprm->unsafe |= LSM_UNSAFE_SHARE;
- } else {
- res = -EAGAIN;
- if (!p->fs->in_exec) {
- p->fs->in_exec = 1;
- res = 1;
- }
- }
+ else
+ p->fs->in_exec = 1;
spin_unlock(&p->fs->lock);
-
- return res;
}
-/*
- * Fill the binprm structure from the inode.
+/*
+ * Fill the binprm structure from the inode.
* Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
*
* This may be called multiple times for binary chains (scripts for example).
@@ -1430,14 +1428,7 @@ static int exec_binprm(struct linux_binprm *bprm)
audit_bprm(bprm);
trace_sched_process_exec(current, old_pid, bprm);
ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
- current->did_exec = 1;
proc_exec_connector(current);
-
- if (bprm->file) {
- allow_write_access(bprm->file);
- fput(bprm->file);
- bprm->file = NULL; /* to catch use-after-free */
- }
}
return ret;
@@ -1446,16 +1437,18 @@ static int exec_binprm(struct linux_binprm *bprm)
/*
* sys_execve() executes a new program.
*/
-static int do_execve_common(const char *filename,
+static int do_execve_common(struct filename *filename,
struct user_arg_ptr argv,
struct user_arg_ptr envp)
{
struct linux_binprm *bprm;
struct file *file;
struct files_struct *displaced;
- bool clear_in_exec;
int retval;
+ if (IS_ERR(filename))
+ return PTR_ERR(filename);
+
/*
* We move the actual failure in case of RLIMIT_NPROC excess from
* set*uid() to execve() because too many poorly written programs
@@ -1485,13 +1478,10 @@ static int do_execve_common(const char *filename,
if (retval)
goto out_free;
- retval = check_unsafe_exec(bprm);
- if (retval < 0)
- goto out_free;
- clear_in_exec = retval;
+ check_unsafe_exec(bprm);
current->in_execve = 1;
- file = open_exec(filename);
+ file = do_open_exec(filename);
retval = PTR_ERR(file);
if (IS_ERR(file))
goto out_unmark;
@@ -1499,12 +1489,11 @@ static int do_execve_common(const char *filename,
sched_exec();
bprm->file = file;
- bprm->filename = filename;
- bprm->interp = filename;
+ bprm->filename = bprm->interp = filename->name;
retval = bprm_mm_init(bprm);
if (retval)
- goto out_file;
+ goto out_unmark;
bprm->argc = count(argv, MAX_ARG_STRINGS);
if ((retval = bprm->argc) < 0)
@@ -1541,6 +1530,7 @@ static int do_execve_common(const char *filename,
acct_update_integrals(current);
task_numa_free(current);
free_bprm(bprm);
+ putname(filename);
if (displaced)
put_files_struct(displaced);
return retval;
@@ -1551,15 +1541,8 @@ out:
mmput(bprm->mm);
}
-out_file:
- if (bprm->file) {
- allow_write_access(bprm->file);
- fput(bprm->file);
- }
-
out_unmark:
- if (clear_in_exec)
- current->fs->in_exec = 0;
+ current->fs->in_exec = 0;
current->in_execve = 0;
out_free:
@@ -1569,10 +1552,11 @@ out_files:
if (displaced)
reset_files_struct(displaced);
out_ret:
+ putname(filename);
return retval;
}
-int do_execve(const char *filename,
+int do_execve(struct filename *filename,
const char __user *const __user *__argv,
const char __user *const __user *__envp)
{
@@ -1582,7 +1566,7 @@ int do_execve(const char *filename,
}
#ifdef CONFIG_COMPAT
-static int compat_do_execve(const char *filename,
+static int compat_do_execve(struct filename *filename,
const compat_uptr_t __user *__argv,
const compat_uptr_t __user *__envp)
{
@@ -1609,67 +1593,22 @@ void set_binfmt(struct linux_binfmt *new)
if (new)
__module_get(new->module);
}
-
EXPORT_SYMBOL(set_binfmt);
/*
- * set_dumpable converts traditional three-value dumpable to two flags and
- * stores them into mm->flags. It modifies lower two bits of mm->flags, but
- * these bits are not changed atomically. So get_dumpable can observe the
- * intermediate state. To avoid doing unexpected behavior, get get_dumpable
- * return either old dumpable or new one by paying attention to the order of
- * modifying the bits.
- *
- * dumpable | mm->flags (binary)
- * old new | initial interim final
- * ---------+-----------------------
- * 0 1 | 00 01 01
- * 0 2 | 00 10(*) 11
- * 1 0 | 01 00 00
- * 1 2 | 01 11 11
- * 2 0 | 11 10(*) 00
- * 2 1 | 11 11 01
- *
- * (*) get_dumpable regards interim value of 10 as 11.
+ * set_dumpable stores three-value SUID_DUMP_* into mm->flags.
*/
void set_dumpable(struct mm_struct *mm, int value)
{
- switch (value) {
- case SUID_DUMP_DISABLE:
- clear_bit(MMF_DUMPABLE, &mm->flags);
- smp_wmb();
- clear_bit(MMF_DUMP_SECURELY, &mm->flags);
- break;
- case SUID_DUMP_USER:
- set_bit(MMF_DUMPABLE, &mm->flags);
- smp_wmb();
- clear_bit(MMF_DUMP_SECURELY, &mm->flags);
- break;
- case SUID_DUMP_ROOT:
- set_bit(MMF_DUMP_SECURELY, &mm->flags);
- smp_wmb();
- set_bit(MMF_DUMPABLE, &mm->flags);
- break;
- }
-}
+ unsigned long old, new;
-int __get_dumpable(unsigned long mm_flags)
-{
- int ret;
-
- ret = mm_flags & MMF_DUMPABLE_MASK;
- return (ret > SUID_DUMP_USER) ? SUID_DUMP_ROOT : ret;
-}
+ if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
+ return;
-/*
- * This returns the actual value of the suid_dumpable flag. For things
- * that are using this for checking for privilege transitions, it must
- * test against SUID_DUMP_USER rather than treating it as a boolean
- * value.
- */
-int get_dumpable(struct mm_struct *mm)
-{
- return __get_dumpable(mm->flags);
+ do {
+ old = ACCESS_ONCE(mm->flags);
+ new = (old & ~MMF_DUMPABLE_MASK) | value;
+ } while (cmpxchg(&mm->flags, old, new) != old);
}
SYSCALL_DEFINE3(execve,
@@ -1677,25 +1616,13 @@ SYSCALL_DEFINE3(execve,
const char __user *const __user *, argv,
const char __user *const __user *, envp)
{
- struct filename *path = getname(filename);
- int error = PTR_ERR(path);
- if (!IS_ERR(path)) {
- error = do_execve(path->name, argv, envp);
- putname(path);
- }
- return error;
+ return do_execve(getname(filename), argv, envp);
}
#ifdef CONFIG_COMPAT
asmlinkage long compat_sys_execve(const char __user * filename,
const compat_uptr_t __user * argv,
const compat_uptr_t __user * envp)
{
- struct filename *path = getname(filename);
- int error = PTR_ERR(path);
- if (!IS_ERR(path)) {
- error = compat_do_execve(path->name, argv, envp);
- putname(path);
- }
- return error;
+ return compat_do_execve(getname(filename), argv, envp);
}
#endif
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-13 02:24:44 +0000