From 81bf9b1a9f6def4a6f742a6b41ddc92005ab638f Mon Sep 17 00:00:00 2001
From: Jakub Zelenka <bukka@php.net>
Date: Sat, 2 Oct 2021 22:53:41 +0100
Subject: [PATCH] Fix bug #81026 (PHP-FPM oob R/W in root process leading to
priv escalation)
The main change is to store scoreboard procs directly to the variable sized
array rather than indirectly through the pointer.
Signed-off-by: Stanislav Malyshev <stas@php.net>
---
sapi/fpm/fpm/fpm_children.c | 14 ++---
sapi/fpm/fpm/fpm_request.c | 4 +-
sapi/fpm/fpm/fpm_scoreboard.c | 106 ++++++++++++++++++++-------------
sapi/fpm/fpm/fpm_scoreboard.h | 11 ++--
sapi/fpm/fpm/fpm_status.c | 4 +-
sapi/fpm/fpm/fpm_worker_pool.c | 2 +-
6 files changed, 81 insertions(+), 60 deletions(-)
diff --git a/sapi/fpm/fpm/fpm_children.c b/sapi/fpm/fpm/fpm_children.c
index fd121372f37c..912f77c11aa7 100644
--- a/sapi/fpm/fpm/fpm_children.c
+++ b/sapi/fpm/fpm/fpm_children.c
@@ -246,7 +246,7 @@ void fpm_children_bury() /* {{{ */
fpm_child_unlink(child);
- fpm_scoreboard_proc_free(wp->scoreboard, child->scoreboard_i);
+ fpm_scoreboard_proc_free(child);
fpm_clock_get(&tv1);
@@ -256,9 +256,9 @@ void fpm_children_bury() /* {{{ */
if (!fpm_pctl_can_spawn_children()) {
severity = ZLOG_DEBUG;
}
- zlog(severity, "[pool %s] child %d exited %s after %ld.%06d seconds from start", child->wp->config->name, (int) pid, buf, tv2.tv_sec, (int) tv2.tv_usec);
+ zlog(severity, "[pool %s] child %d exited %s after %ld.%06d seconds from start", wp->config->name, (int) pid, buf, tv2.tv_sec, (int) tv2.tv_usec);
} else {
- zlog(ZLOG_DEBUG, "[pool %s] child %d has been killed by the process management after %ld.%06d seconds from start", child->wp->config->name, (int) pid, tv2.tv_sec, (int) tv2.tv_usec);
+ zlog(ZLOG_DEBUG, "[pool %s] child %d has been killed by the process management after %ld.%06d seconds from start", wp->config->name, (int) pid, tv2.tv_sec, (int) tv2.tv_usec);
}
fpm_child_close(child, 1 /* in event_loop */);
@@ -324,7 +324,7 @@ static struct fpm_child_s *fpm_resources_prepare(struct fpm_worker_pool_s *wp) /
return 0;
}
- if (0 > fpm_scoreboard_proc_alloc(wp->scoreboard, &c->scoreboard_i)) {
+ if (0 > fpm_scoreboard_proc_alloc(c)) {
fpm_stdio_discard_pipes(c);
fpm_child_free(c);
return 0;
@@ -336,7 +336,7 @@ static struct fpm_child_s *fpm_resources_prepare(struct fpm_worker_pool_s *wp) /
static void fpm_resources_discard(struct fpm_child_s *child) /* {{{ */
{
- fpm_scoreboard_proc_free(child->wp->scoreboard, child->scoreboard_i);
+ fpm_scoreboard_proc_free(child);
fpm_stdio_discard_pipes(child);
fpm_child_free(child);
}
@@ -349,10 +349,10 @@ static void fpm_child_resources_use(struct fpm_child_s *child) /* {{{ */
if (wp == child->wp) {
continue;
}
- fpm_scoreboard_free(wp->scoreboard);
+ fpm_scoreboard_free(wp);
}
- fpm_scoreboard_child_use(child->wp->scoreboard, child->scoreboard_i, getpid());
+ fpm_scoreboard_child_use(child, getpid());
fpm_stdio_child_use_pipes(child);
fpm_child_free(child);
}
diff --git a/sapi/fpm/fpm/fpm_request.c b/sapi/fpm/fpm/fpm_request.c
index c80aa144628f..0a6f6a7cfbf0 100644
--- a/sapi/fpm/fpm/fpm_request.c
+++ b/sapi/fpm/fpm/fpm_request.c
@@ -285,7 +285,7 @@ int fpm_request_is_idle(struct fpm_child_s *child) /* {{{ */
struct fpm_scoreboard_proc_s *proc;
/* no need in atomicity here */
- proc = fpm_scoreboard_proc_get(child->wp->scoreboard, child->scoreboard_i);
+ proc = fpm_scoreboard_proc_get_from_child(child);
if (!proc) {
return 0;
}
@@ -300,7 +300,7 @@ int fpm_request_last_activity(struct fpm_child_s *child, struct timeval *tv) /*
if (!tv) return -1;
- proc = fpm_scoreboard_proc_get(child->wp->scoreboard, child->scoreboard_i);
+ proc = fpm_scoreboard_proc_get_from_child(child);
if (!proc) {
return -1;
}
diff --git a/sapi/fpm/fpm/fpm_scoreboard.c b/sapi/fpm/fpm/fpm_scoreboard.c
index 328f999f0c9b..7e9da4d6848a 100644
--- a/sapi/fpm/fpm/fpm_scoreboard.c
+++ b/sapi/fpm/fpm/fpm_scoreboard.c
@@ -6,6 +6,7 @@
#include <time.h>
#include "fpm_config.h"
+#include "fpm_children.h"
#include "fpm_scoreboard.h"
#include "fpm_shm.h"
#include "fpm_sockets.h"
@@ -23,7 +24,6 @@ static float fpm_scoreboard_tick;
int fpm_scoreboard_init_main() /* {{{ */
{
struct fpm_worker_pool_s *wp;
- unsigned int i;
#ifdef HAVE_TIMES
#if (defined(HAVE_SYSCONF) && defined(_SC_CLK_TCK))
@@ -40,7 +40,7 @@ int fpm_scoreboard_init_main() /* {{{ */
for (wp = fpm_worker_all_pools; wp; wp = wp->next) {
- size_t scoreboard_size, scoreboard_nprocs_size;
+ size_t scoreboard_procs_size;
void *shm_mem;
if (wp->config->pm_max_children < 1) {
@@ -53,22 +53,15 @@ int fpm_scoreboard_init_main() /* {{{ */
return -1;
}
- scoreboard_size = sizeof(struct fpm_scoreboard_s) + (wp->config->pm_max_children) * sizeof(struct fpm_scoreboard_proc_s *);
- scoreboard_nprocs_size = sizeof(struct fpm_scoreboard_proc_s) * wp->config->pm_max_children;
- shm_mem = fpm_shm_alloc(scoreboard_size + scoreboard_nprocs_size);
+ scoreboard_procs_size = sizeof(struct fpm_scoreboard_proc_s) * wp->config->pm_max_children;
+ shm_mem = fpm_shm_alloc(sizeof(struct fpm_scoreboard_s) + scoreboard_procs_size);
if (!shm_mem) {
return -1;
}
- wp->scoreboard = shm_mem;
+ wp->scoreboard = shm_mem;
+ wp->scoreboard->pm = wp->config->pm;
wp->scoreboard->nprocs = wp->config->pm_max_children;
- shm_mem += scoreboard_size;
-
- for (i = 0; i < wp->scoreboard->nprocs; i++, shm_mem += sizeof(struct fpm_scoreboard_proc_s)) {
- wp->scoreboard->procs[i] = shm_mem;
- }
-
- wp->scoreboard->pm = wp->config->pm;
wp->scoreboard->start_epoch = time(NULL);
strlcpy(wp->scoreboard->pool, wp->config->name, sizeof(wp->scoreboard->pool));
}
@@ -162,28 +155,48 @@ struct fpm_scoreboard_s *fpm_scoreboard_get() /* {{{*/
}
/* }}} */
-struct fpm_scoreboard_proc_s *fpm_scoreboard_proc_get(struct fpm_scoreboard_s *scoreboard, int child_index) /* {{{*/
+static inline struct fpm_scoreboard_proc_s *fpm_scoreboard_proc_get_ex(
+ struct fpm_scoreboard_s *scoreboard, int child_index, unsigned int nprocs) /* {{{*/
{
if (!scoreboard) {
- scoreboard = fpm_scoreboard;
+ return NULL;
}
- if (!scoreboard) {
+ if (child_index < 0 || (unsigned int)child_index >= nprocs) {
return NULL;
}
+ return &scoreboard->procs[child_index];
+}
+/* }}} */
+
+struct fpm_scoreboard_proc_s *fpm_scoreboard_proc_get(
+ struct fpm_scoreboard_s *scoreboard, int child_index) /* {{{*/
+{
+ if (!scoreboard) {
+ scoreboard = fpm_scoreboard;
+ }
+
if (child_index < 0) {
child_index = fpm_scoreboard_i;
}
- if (child_index < 0 || (unsigned int)child_index >= scoreboard->nprocs) {
- return NULL;
- }
+ return fpm_scoreboard_proc_get_ex(scoreboard, child_index, scoreboard->nprocs);
+}
+/* }}} */
- return scoreboard->procs[child_index];
+struct fpm_scoreboard_proc_s *fpm_scoreboard_proc_get_from_child(struct fpm_child_s *child) /* {{{*/
+{
+ struct fpm_worker_pool_s *wp = child->wp;
+ unsigned int nprocs = wp->config->pm_max_children;
+ struct fpm_scoreboard_s *scoreboard = wp->scoreboard;
+ int child_index = child->scoreboard_i;
+
+ return fpm_scoreboard_proc_get_ex(scoreboard, child_index, nprocs);
}
/* }}} */
+
struct fpm_scoreboard_s *fpm_scoreboard_acquire(struct fpm_scoreboard_s *scoreboard, int nohang) /* {{{ */
{
struct fpm_scoreboard_s *s;
@@ -234,28 +247,28 @@ void fpm_scoreboard_proc_release(struct fpm_scoreboard_proc_s *proc) /* {{{ */
proc->lock = 0;
}
-void fpm_scoreboard_free(struct fpm_scoreboard_s *scoreboard) /* {{{ */
+void fpm_scoreboard_free(struct fpm_worker_pool_s *wp) /* {{{ */
{
- size_t scoreboard_size, scoreboard_nprocs_size;
+ size_t scoreboard_procs_size;
+ struct fpm_scoreboard_s *scoreboard = wp->scoreboard;
if (!scoreboard) {
zlog(ZLOG_ERROR, "**scoreboard is NULL");
return;
}
- scoreboard_size = sizeof(struct fpm_scoreboard_s) + (scoreboard->nprocs) * sizeof(struct fpm_scoreboard_proc_s *);
- scoreboard_nprocs_size = sizeof(struct fpm_scoreboard_proc_s) * scoreboard->nprocs;
+ scoreboard_procs_size = sizeof(struct fpm_scoreboard_proc_s) * wp->config->pm_max_children;
- fpm_shm_free(scoreboard, scoreboard_size + scoreboard_nprocs_size);
+ fpm_shm_free(scoreboard, sizeof(struct fpm_scoreboard_s) + scoreboard_procs_size);
}
/* }}} */
-void fpm_scoreboard_child_use(struct fpm_scoreboard_s *scoreboard, int child_index, pid_t pid) /* {{{ */
+void fpm_scoreboard_child_use(struct fpm_child_s *child, pid_t pid) /* {{{ */
{
struct fpm_scoreboard_proc_s *proc;
- fpm_scoreboard = scoreboard;
- fpm_scoreboard_i = child_index;
- proc = fpm_scoreboard_proc_get(scoreboard, child_index);
+ fpm_scoreboard = child->wp->scoreboard;
+ fpm_scoreboard_i = child->scoreboard_i;
+ proc = fpm_scoreboard_proc_get_from_child(child);
if (!proc) {
return;
}
@@ -264,18 +277,22 @@ void fpm_scoreboard_child_use(struct fpm_scoreboard_s *scoreboard, int child_ind
}
/* }}} */
-void fpm_scoreboard_proc_free(struct fpm_scoreboard_s *scoreboard, int child_index) /* {{{ */
+void fpm_scoreboard_proc_free(struct fpm_child_s *child) /* {{{ */
{
+ struct fpm_worker_pool_s *wp = child->wp;
+ struct fpm_scoreboard_s *scoreboard = wp->scoreboard;
+ int child_index = child->scoreboard_i;
+
if (!scoreboard) {
return;
}
- if (child_index < 0 || (unsigned int)child_index >= scoreboard->nprocs) {
+ if (child_index < 0 || child_index >= wp->config->pm_max_children) {
return;
}
- if (scoreboard->procs[child_index] && scoreboard->procs[child_index]->used > 0) {
- memset(scoreboard->procs[child_index], 0, sizeof(struct fpm_scoreboard_proc_s));
+ if (scoreboard->procs[child_index].used > 0) {
+ memset(&scoreboard->procs[child_index], 0, sizeof(struct fpm_scoreboard_proc_s));
}
/* set this slot as free to avoid search on next alloc */
@@ -283,41 +300,44 @@ void fpm_scoreboard_proc_free(struct fpm_scoreboard_s *scoreboard, int child_ind
}
/* }}} */
-int fpm_scoreboard_proc_alloc(struct fpm_scoreboard_s *scoreboard, int *child_index) /* {{{ */
+int fpm_scoreboard_proc_alloc(struct fpm_child_s *child) /* {{{ */
{
int i = -1;
+ struct fpm_worker_pool_s *wp = child->wp;
+ struct fpm_scoreboard_s *scoreboard = wp->scoreboard;
+ int nprocs = wp->config->pm_max_children;
- if (!scoreboard || !child_index) {
+ if (!scoreboard) {
return -1;
}
/* first try the slot which is supposed to be free */
- if (scoreboard->free_proc >= 0 && (unsigned int)scoreboard->free_proc < scoreboard->nprocs) {
- if (scoreboard->procs[scoreboard->free_proc] && !scoreboard->procs[scoreboard->free_proc]->used) {
+ if (scoreboard->free_proc >= 0 && scoreboard->free_proc < nprocs) {
+ if (!scoreboard->procs[scoreboard->free_proc].used) {
i = scoreboard->free_proc;
}
}
if (i < 0) { /* the supposed free slot is not, let's search for a free slot */
zlog(ZLOG_DEBUG, "[pool %s] the proc->free_slot was not free. Let's search", scoreboard->pool);
- for (i = 0; i < (int)scoreboard->nprocs; i++) {
- if (scoreboard->procs[i] && !scoreboard->procs[i]->used) { /* found */
+ for (i = 0; i < nprocs; i++) {
+ if (!scoreboard->procs[i].used) { /* found */
break;
}
}
}
/* no free slot */
- if (i < 0 || i >= (int)scoreboard->nprocs) {
+ if (i < 0 || i >= nprocs) {
zlog(ZLOG_ERROR, "[pool %s] no free scoreboard slot", scoreboard->pool);
return -1;
}
- scoreboard->procs[i]->used = 1;
- *child_index = i;
+ scoreboard->procs[i].used = 1;
+ child->scoreboard_i = i;
/* supposed next slot is free */
- if (i + 1 >= (int)scoreboard->nprocs) {
+ if (i + 1 >= nprocs) {
scoreboard->free_proc = 0;
} else {
scoreboard->free_proc = i + 1;
diff --git a/sapi/fpm/fpm/fpm_scoreboard.h b/sapi/fpm/fpm/fpm_scoreboard.h
index 1fecde1d0feb..9d5981e1c739 100644
--- a/sapi/fpm/fpm/fpm_scoreboard.h
+++ b/sapi/fpm/fpm/fpm_scoreboard.h
@@ -63,7 +63,7 @@ struct fpm_scoreboard_s {
unsigned int nprocs;
int free_proc;
unsigned long int slow_rq;
- struct fpm_scoreboard_proc_s *procs[];
+ struct fpm_scoreboard_proc_s procs[];
};
int fpm_scoreboard_init_main();
@@ -72,18 +72,19 @@ int fpm_scoreboard_init_child(struct fpm_worker_pool_s *wp);
void fpm_scoreboard_update(int idle, int active, int lq, int lq_len, int requests, int max_children_reached, int slow_rq, int action, struct fpm_scoreboard_s *scoreboard);
struct fpm_scoreboard_s *fpm_scoreboard_get();
struct fpm_scoreboard_proc_s *fpm_scoreboard_proc_get(struct fpm_scoreboard_s *scoreboard, int child_index);
+struct fpm_scoreboard_proc_s *fpm_scoreboard_proc_get_from_child(struct fpm_child_s *child);
struct fpm_scoreboard_s *fpm_scoreboard_acquire(struct fpm_scoreboard_s *scoreboard, int nohang);
void fpm_scoreboard_release(struct fpm_scoreboard_s *scoreboard);
struct fpm_scoreboard_proc_s *fpm_scoreboard_proc_acquire(struct fpm_scoreboard_s *scoreboard, int child_index, int nohang);
void fpm_scoreboard_proc_release(struct fpm_scoreboard_proc_s *proc);
-void fpm_scoreboard_free(struct fpm_scoreboard_s *scoreboard);
+void fpm_scoreboard_free(struct fpm_worker_pool_s *wp);
-void fpm_scoreboard_child_use(struct fpm_scoreboard_s *scoreboard, int child_index, pid_t pid);
+void fpm_scoreboard_child_use(struct fpm_child_s *child, pid_t pid);
-void fpm_scoreboard_proc_free(struct fpm_scoreboard_s *scoreboard, int child_index);
-int fpm_scoreboard_proc_alloc(struct fpm_scoreboard_s *scoreboard, int *child_index);
+void fpm_scoreboard_proc_free(struct fpm_child_s *child);
+int fpm_scoreboard_proc_alloc(struct fpm_child_s *child);
#ifdef HAVE_TIMES
float fpm_scoreboard_get_tick();
diff --git a/sapi/fpm/fpm/fpm_status.c b/sapi/fpm/fpm/fpm_status.c
index 36d224063583..de8db9d61a25 100644
--- a/sapi/fpm/fpm/fpm_status.c
+++ b/sapi/fpm/fpm/fpm_status.c
@@ -498,10 +498,10 @@ int fpm_status_handle_request(void) /* {{{ */
first = 1;
for (i=0; i<scoreboard_p->nprocs; i++) {
- if (!scoreboard_p->procs[i] || !scoreboard_p->procs[i]->used) {
+ if (!scoreboard_p->procs[i].used) {
continue;
}
- proc = *scoreboard_p->procs[i];
+ proc = scoreboard_p->procs[i];
if (first) {
first = 0;
diff --git a/sapi/fpm/fpm/fpm_worker_pool.c b/sapi/fpm/fpm/fpm_worker_pool.c
index d04528f4e0d0..65a9b226b1ae 100644
--- a/sapi/fpm/fpm/fpm_worker_pool.c
+++ b/sapi/fpm/fpm/fpm_worker_pool.c
@@ -54,7 +54,7 @@ static void fpm_worker_pool_cleanup(int which, void *arg) /* {{{ */
fpm_worker_pool_config_free(wp->config);
fpm_children_free(wp->children);
if ((which & FPM_CLEANUP_CHILD) == 0 && fpm_globals.parent_pid == getpid()) {
- fpm_scoreboard_free(wp->scoreboard);
+ fpm_scoreboard_free(wp);
}
fpm_worker_pool_free(wp);
}