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-rw-r--r--kernel/sys.c158
1 files changed, 88 insertions, 70 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index ecc4cf019242..374f83e95239 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -7,6 +7,7 @@
#include <linux/export.h>
#include <linux/mm.h>
+#include <linux/mm_inline.h>
#include <linux/utsname.h>
#include <linux/mman.h>
#include <linux/reboot.h>
@@ -472,6 +473,16 @@ static int set_user(struct cred *new)
if (!new_user)
return -EAGAIN;
+ free_uid(new->user);
+ new->user = new_user;
+ return 0;
+}
+
+static void flag_nproc_exceeded(struct cred *new)
+{
+ if (new->ucounts == current_ucounts())
+ return;
+
/*
* We don't fail in case of NPROC limit excess here because too many
* poorly written programs don't check set*uid() return code, assuming
@@ -480,15 +491,10 @@ static int set_user(struct cred *new)
* failure to the execve() stage.
*/
if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
- new_user != INIT_USER &&
- !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
+ new->user != INIT_USER)
current->flags |= PF_NPROC_EXCEEDED;
else
current->flags &= ~PF_NPROC_EXCEEDED;
-
- free_uid(new->user);
- new->user = new_user;
- return 0;
}
/*
@@ -563,6 +569,7 @@ long __sys_setreuid(uid_t ruid, uid_t euid)
if (retval < 0)
goto error;
+ flag_nproc_exceeded(new);
return commit_creds(new);
error:
@@ -625,6 +632,7 @@ long __sys_setuid(uid_t uid)
if (retval < 0)
goto error;
+ flag_nproc_exceeded(new);
return commit_creds(new);
error:
@@ -704,6 +712,7 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
if (retval < 0)
goto error;
+ flag_nproc_exceeded(new);
return commit_creds(new);
error:
@@ -1415,6 +1424,68 @@ SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
return errno;
}
+/* make sure you are allowed to change @tsk limits before calling this */
+static int do_prlimit(struct task_struct *tsk, unsigned int resource,
+ struct rlimit *new_rlim, struct rlimit *old_rlim)
+{
+ struct rlimit *rlim;
+ int retval = 0;
+
+ if (resource >= RLIM_NLIMITS)
+ return -EINVAL;
+ if (new_rlim) {
+ if (new_rlim->rlim_cur > new_rlim->rlim_max)
+ return -EINVAL;
+ if (resource == RLIMIT_NOFILE &&
+ new_rlim->rlim_max > sysctl_nr_open)
+ return -EPERM;
+ }
+
+ /* Holding a refcount on tsk protects tsk->signal from disappearing. */
+ rlim = tsk->signal->rlim + resource;
+ task_lock(tsk->group_leader);
+ if (new_rlim) {
+ /*
+ * Keep the capable check against init_user_ns until cgroups can
+ * contain all limits.
+ */
+ if (new_rlim->rlim_max > rlim->rlim_max &&
+ !capable(CAP_SYS_RESOURCE))
+ retval = -EPERM;
+ if (!retval)
+ retval = security_task_setrlimit(tsk, resource, new_rlim);
+ }
+ if (!retval) {
+ if (old_rlim)
+ *old_rlim = *rlim;
+ if (new_rlim)
+ *rlim = *new_rlim;
+ }
+ task_unlock(tsk->group_leader);
+
+ /*
+ * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
+ * infinite. In case of RLIM_INFINITY the posix CPU timer code
+ * ignores the rlimit.
+ */
+ if (!retval && new_rlim && resource == RLIMIT_CPU &&
+ new_rlim->rlim_cur != RLIM_INFINITY &&
+ IS_ENABLED(CONFIG_POSIX_TIMERS)) {
+ /*
+ * update_rlimit_cpu can fail if the task is exiting, but there
+ * may be other tasks in the thread group that are not exiting,
+ * and they need their cpu timers adjusted.
+ *
+ * The group_leader is the last task to be released, so if we
+ * cannot update_rlimit_cpu on it, then the entire process is
+ * exiting and we do not need to update at all.
+ */
+ update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
+ }
+
+ return retval;
+}
+
SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
{
struct rlimit value;
@@ -1558,63 +1629,6 @@ static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
rlim->rlim_max = (unsigned long)rlim64->rlim_max;
}
-/* make sure you are allowed to change @tsk limits before calling this */
-int do_prlimit(struct task_struct *tsk, unsigned int resource,
- struct rlimit *new_rlim, struct rlimit *old_rlim)
-{
- struct rlimit *rlim;
- int retval = 0;
-
- if (resource >= RLIM_NLIMITS)
- return -EINVAL;
- if (new_rlim) {
- if (new_rlim->rlim_cur > new_rlim->rlim_max)
- return -EINVAL;
- if (resource == RLIMIT_NOFILE &&
- new_rlim->rlim_max > sysctl_nr_open)
- return -EPERM;
- }
-
- /* protect tsk->signal and tsk->sighand from disappearing */
- read_lock(&tasklist_lock);
- if (!tsk->sighand) {
- retval = -ESRCH;
- goto out;
- }
-
- rlim = tsk->signal->rlim + resource;
- task_lock(tsk->group_leader);
- if (new_rlim) {
- /* Keep the capable check against init_user_ns until
- cgroups can contain all limits */
- if (new_rlim->rlim_max > rlim->rlim_max &&
- !capable(CAP_SYS_RESOURCE))
- retval = -EPERM;
- if (!retval)
- retval = security_task_setrlimit(tsk, resource, new_rlim);
- }
- if (!retval) {
- if (old_rlim)
- *old_rlim = *rlim;
- if (new_rlim)
- *rlim = *new_rlim;
- }
- task_unlock(tsk->group_leader);
-
- /*
- * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
- * infinite. In case of RLIM_INFINITY the posix CPU timer code
- * ignores the rlimit.
- */
- if (!retval && new_rlim && resource == RLIMIT_CPU &&
- new_rlim->rlim_cur != RLIM_INFINITY &&
- IS_ENABLED(CONFIG_POSIX_TIMERS))
- update_rlimit_cpu(tsk, new_rlim->rlim_cur);
-out:
- read_unlock(&tasklist_lock);
- return retval;
-}
-
/* rcu lock must be held */
static int check_prlimit_permission(struct task_struct *task,
unsigned int flags)
@@ -2278,15 +2292,16 @@ static int prctl_set_vma(unsigned long opt, unsigned long addr,
{
struct mm_struct *mm = current->mm;
const char __user *uname;
- char *name, *pch;
+ struct anon_vma_name *anon_name = NULL;
int error;
switch (opt) {
case PR_SET_VMA_ANON_NAME:
uname = (const char __user *)arg;
if (uname) {
- name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
+ char *name, *pch;
+ name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
if (IS_ERR(name))
return PTR_ERR(name);
@@ -2296,15 +2311,18 @@ static int prctl_set_vma(unsigned long opt, unsigned long addr,
return -EINVAL;
}
}
- } else {
- /* Reset the name */
- name = NULL;
+ /* anon_vma has its own copy */
+ anon_name = anon_vma_name_alloc(name);
+ kfree(name);
+ if (!anon_name)
+ return -ENOMEM;
+
}
mmap_write_lock(mm);
- error = madvise_set_anon_name(mm, addr, size, name);
+ error = madvise_set_anon_name(mm, addr, size, anon_name);
mmap_write_unlock(mm);
- kfree(name);
+ anon_vma_name_put(anon_name);
break;
default:
error = -EINVAL;
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-02 02:42:31 +0000