* [syzbot] [kernel?] KASAN: slab-use-after-free Read in kill_orphaned_pgrp
@ 2023-11-21 14:33 syzbot
0 siblings, 0 replies; 2+ messages in thread
From: syzbot @ 2023-11-21 14:33 UTC (permalink / raw)
To: linux-kernel, luto, peterz, syzkaller-bugs, tglx
Hello,
syzbot found the following issue on:
HEAD commit: 0bb80ecc33a8 Linux 6.6-rc1
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=139b08d8680000
kernel config: https://syzkaller.appspot.com/x/.config?x=f4894cf58531f
dashboard link: https://syzkaller.appspot.com/bug?extid=50ef815ba3bcce06d409
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eeb0cac260c7/disk-0bb80ecc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a3c360110254/vmlinux-0bb80ecc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/22b81065ba5f/bzImage-0bb80ecc.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+50ef815ba3bcce06d409@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-use-after-free in task_pgrp include/linux/sched/signal.h:694 [inline]
BUG: KASAN: slab-use-after-free in kill_orphaned_pgrp+0x2e1/0x340 kernel/exit.c:376
Read of size 8 at addr ffff88802d78a6b8 by task vhost-16506/16518
CPU: 0 PID: 16518 Comm: vhost-16506 Not tainted 6.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xc4/0x620 mm/kasan/report.c:475
kasan_report+0xda/0x110 mm/kasan/report.c:588
task_pgrp include/linux/sched/signal.h:694 [inline]
kill_orphaned_pgrp+0x2e1/0x340 kernel/exit.c:376
exit_notify kernel/exit.c:737 [inline]
do_exit+0x1cb5/0x2a20 kernel/exit.c:894
vhost_task_fn+0x2e6/0x370 kernel/vhost_task.c:61
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
</TASK>
Allocated by task 5090:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:762 [inline]
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x185/0x3f0 mm/slub.c:3523
alloc_task_struct_node kernel/fork.c:173 [inline]
dup_task_struct kernel/fork.c:1110 [inline]
copy_process+0x41c/0x7400 kernel/fork.c:2327
kernel_clone+0xfd/0x930 kernel/fork.c:2909
__do_sys_clone+0xba/0x100 kernel/fork.c:3052
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 42:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1800 [inline]
slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826
slab_free mm/slub.c:3809 [inline]
kmem_cache_free+0xf0/0x480 mm/slub.c:3831
put_task_struct include/linux/sched/task.h:136 [inline]
put_task_struct include/linux/sched/task.h:123 [inline]
delayed_put_task_struct+0x246/0x2c0 kernel/exit.c:226
rcu_do_batch kernel/rcu/tree.c:2139 [inline]
rcu_core+0x7fb/0x1bb0 kernel/rcu/tree.c:2403
__do_softirq+0x218/0x965 kernel/softirq.c:553
Last potentially related work creation:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
__kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492
__call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
put_task_struct_rcu_user kernel/exit.c:232 [inline]
put_task_struct_rcu_user+0x87/0xc0 kernel/exit.c:229
release_task+0xf0a/0x1b90 kernel/exit.c:282
de_thread fs/exec.c:1158 [inline]
begin_new_exec+0x226c/0x3110 fs/exec.c:1264
load_elf_binary+0x8ec/0x5c40 fs/binfmt_elf.c:1001
search_binary_handler fs/exec.c:1739 [inline]
exec_binprm fs/exec.c:1781 [inline]
bprm_execve fs/exec.c:1856 [inline]
bprm_execve+0x80a/0x1a50 fs/exec.c:1812
do_execveat_common.isra.0+0x5d3/0x740 fs/exec.c:1964
do_execve fs/exec.c:2038 [inline]
__do_sys_execve fs/exec.c:2114 [inline]
__se_sys_execve fs/exec.c:2109 [inline]
__x64_sys_execve+0x8c/0xb0 fs/exec.c:2109
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Second to last potentially related work creation:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
__kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492
__call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653
put_task_struct_rcu_user kernel/exit.c:232 [inline]
put_task_struct_rcu_user+0x87/0xc0 kernel/exit.c:229
context_switch kernel/sched/core.c:5385 [inline]
__schedule+0xee9/0x59f0 kernel/sched/core.c:6695
preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7007
irqentry_exit+0x35/0x80 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
The buggy address belongs to the object at ffff88802d789dc0
which belongs to the cache task_struct of size 7360
The buggy address is located 2296 bytes inside of
freed 7360-byte region [ffff88802d789dc0, ffff88802d78ba80)
The buggy address belongs to the physical page:
page:ffffea0000b5e200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2d788
head:ffffea0000b5e200 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888075f26101
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888014e49500 ffffea0001e00e00 dead000000000002
raw: 0000000000000000 0000000000040004 00000001ffffffff ffff888075f26101
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5278, tgid 5278 (syz-executor.3), ts 190312746205, free_ts 190291479937
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536
prep_new_page mm/page_alloc.c:1543 [inline]
get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170
__alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426
alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298
alloc_slab_page mm/slub.c:1870 [inline]
allocate_slab+0x251/0x380 mm/slub.c:2017
new_slab mm/slub.c:2070 [inline]
___slab_alloc+0x8be/0x1570 mm/slub.c:3223
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322
__slab_alloc_node mm/slub.c:3375 [inline]
slab_alloc_node mm/slub.c:3468 [inline]
kmem_cache_alloc_node+0x137/0x3f0 mm/slub.c:3523
alloc_task_struct_node kernel/fork.c:173 [inline]
dup_task_struct kernel/fork.c:1110 [inline]
copy_process+0x41c/0x7400 kernel/fork.c:2327
kernel_clone+0xfd/0x930 kernel/fork.c:2909
__do_sys_clone3+0x1f1/0x260 kernel/fork.c:3210
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1136 [inline]
free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312
free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405
__folio_put+0xeb/0x110 mm/swap.c:127
folio_put include/linux/mm.h:1475 [inline]
put_page include/linux/mm.h:1544 [inline]
do_exit+0x2332/0x2a20 kernel/exit.c:913
do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
get_signal+0x23d1/0x27b0 kernel/signal.c:2892
arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296
do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Memory state around the buggy address:
ffff88802d78a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802d78a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802d78a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802d78a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802d78a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
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^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] [kernel?] KASAN: slab-use-after-free Read in kill_orphaned_pgrp
@ 2023-11-22 6:13 xingwei lee
0 siblings, 0 replies; 2+ messages in thread
From: xingwei lee @ 2023-11-22 6:13 UTC (permalink / raw)
To: syzbot+50ef815ba3bcce06d409
Cc: linux-kernel, luto, peterz, syzkaller-bugs, tglx
Hi! I reproduce this bug.
Without analyzing deeply, I find the other bug titled "KASAN:
slab-use-after-free read in do_acct_process" or titled "KASAN:
slab-use-after-free in release_task" may also be the same because with
the same reproducer.
repro.txt
r0 = creat(&(0x7f0000000280)='./file0\x00', 0xecf86c37d53049cc)
write$binfmt_elf32(r0, &(0x7f0000000440)={{0x7f, 0x45, 0x4c, 0x46,
0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x3e, 0x0, 0x0, 0x38, 0x0, 0x0, 0xeb0,
0x20, 0x2}, [{}], "", ['\x00', '\x00', '\x00', '\x00', '\x00', '\x00',
'\x00']}, 0x758)
close(r0)
r1 = openat$vnet(0xffffffffffffff9c, &(0x7f0000000000), 0x2, 0x0)
ioctl$int_in(r1, 0x40000000af01, 0x0)
execve(&(0x7f0000000400)='./file0\x00', 0x0, 0x0)
repro.c
#define _GNU_SOURCE
#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <linux/futex.h>
static void sleep_ms(uint64_t ms)
{
usleep(ms * 1000);
}
static uint64_t current_time_ms(void)
{
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts))
exit(1);
return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}
static void thread_start(void* (*fn)(void*), void* arg)
{
pthread_t th;
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, 128 << 10);
int i = 0;
for (; i < 100; i++) {
if (pthread_create(&th, &attr, fn, arg) == 0) {
pthread_attr_destroy(&attr);
return;
}
if (errno == EAGAIN) {
usleep(50);
continue;
}
break;
}
exit(1);
}
typedef struct {
int state;
} event_t;
static void event_init(event_t* ev)
{
ev->state = 0;
}
static void event_reset(event_t* ev)
{
ev->state = 0;
}
static void event_set(event_t* ev)
{
if (ev->state)
exit(1);
__atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
syscall(SYS_futex, &ev->state, FUTEX_WAKE |
FUTEX_PRIVATE_FLAG, 1000000);
}
static void event_wait(event_t* ev)
{
while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
syscall(SYS_futex, &ev->state, FUTEX_WAIT |
FUTEX_PRIVATE_FLAG, 0, 0);
}
static int event_isset(event_t* ev)
{
return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}
static int event_timedwait(event_t* ev, uint64_t timeout)
{
uint64_t start = current_time_ms();
uint64_t now = start;
for (;;) {
uint64_t remain = timeout - (now - start);
struct timespec ts;
ts.tv_sec = remain / 1000;
ts.tv_nsec = (remain % 1000) * 1000 * 1000;
syscall(SYS_futex, &ev->state, FUTEX_WAIT |
FUTEX_PRIVATE_FLAG, 0, &ts);
if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
return 1;
now = current_time_ms();
if (now - start > timeout)
return 0;
}
}
static bool write_file(const char* file, const char* what, ...)
{
char buf[1024];
va_list args;
va_start(args, what);
vsnprintf(buf, sizeof(buf), what, args);
va_end(args);
buf[sizeof(buf) - 1] = 0;
int len = strlen(buf);
int fd = open(file, O_WRONLY | O_CLOEXEC);
if (fd == -1)
return false;
if (write(fd, buf, len) != len) {
int err = errno;
close(fd);
errno = err;
return false;
}
close(fd);
return true;
}
static void kill_and_wait(int pid, int* status)
{
kill(-pid, SIGKILL);
kill(pid, SIGKILL);
for (int i = 0; i < 100; i++) {
if (waitpid(-1, status, WNOHANG | __WALL) == pid)
return;
usleep(1000);
}
DIR* dir = opendir("/sys/fs/fuse/connections");
if (dir) {
for (;;) {
struct dirent* ent = readdir(dir);
if (!ent)
break;
if (strcmp(ent->d_name, ".") == 0 ||
strcmp(ent->d_name, "..") == 0)
continue;
char abort[300];
snprintf(abort, sizeof(abort),
"/sys/fs/fuse/connections/%s/abort", ent->d_name);
int fd = open(abort, O_WRONLY);
if (fd == -1) {
continue;
}
if (write(fd, abort, 1) < 0) {
}
close(fd);
}
closedir(dir);
} else {
}
while (waitpid(-1, status, __WALL) != pid) {
}
}
static void setup_test()
{
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
setpgrp();
write_file("/proc/self/oom_score_adj", "1000");
}
struct thread_t {
int created, call;
event_t ready, done;
};
static struct thread_t threads[16];
static void execute_call(int call);
static int running;
static void* thr(void* arg)
{
struct thread_t* th = (struct thread_t*)arg;
for (;;) {
event_wait(&th->ready);
event_reset(&th->ready);
execute_call(th->call);
__atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
event_set(&th->done);
}
return 0;
}
static void execute_one(void)
{
int i, call, thread;
for (call = 0; call < 6; call++) {
for (thread = 0; thread < (int)(sizeof(threads) /
sizeof(threads[0])); thread++) {
struct thread_t* th = &threads[thread];
if (!th->created) {
th->created = 1;
event_init(&th->ready);
event_init(&th->done);
event_set(&th->done);
thread_start(thr, th);
}
if (!event_isset(&th->done))
continue;
event_reset(&th->done);
th->call = call;
__atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
event_set(&th->ready);
event_timedwait(&th->done, 50);
break;
}
}
for (i = 0; i < 100 && __atomic_load_n(&running,
__ATOMIC_RELAXED); i++)
sleep_ms(1);
}
static void execute_one(void);
#define WAIT_FLAGS __WALL
static void loop(void)
{
int iter = 0;
for (;; iter++) {
int pid = fork();
if (pid < 0)
exit(1);
if (pid == 0) {
setup_test();
execute_one();
exit(0);
}
int status = 0;
uint64_t start = current_time_ms();
for (;;) {
if (waitpid(-1, &status, WNOHANG |
WAIT_FLAGS) == pid)
break;
sleep_ms(1);
if (current_time_ms() - start < 5000)
continue;
kill_and_wait(pid, &status);
break;
}
}
}
uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
void execute_call(int call)
{
intptr_t res = 0;
switch (call) {
case 0:
memcpy((void*)0x20000280, "./file0\000", 8);
res = syscall(__NR_creat, /*file=*/0x20000280ul,
/*mode=*/0xecf86c37d53049ccul);
if (res != -1)
r[0] = res;
break;
case 1:
*(uint8_t*)0x20000440 = 0x7f;
*(uint8_t*)0x20000441 = 0x45;
*(uint8_t*)0x20000442 = 0x4c;
*(uint8_t*)0x20000443 = 0x46;
*(uint8_t*)0x20000444 = 0;
*(uint8_t*)0x20000445 = 0;
*(uint8_t*)0x20000446 = 0;
*(uint8_t*)0x20000447 = 0;
*(uint64_t*)0x20000448 = 0;
*(uint16_t*)0x20000450 = 2;
*(uint16_t*)0x20000452 = 0x3e;
*(uint32_t*)0x20000454 = 0;
*(uint32_t*)0x20000458 = 0;
*(uint32_t*)0x2000045c = 0x38;
*(uint32_t*)0x20000460 = 0;
*(uint32_t*)0x20000464 = 0;
*(uint16_t*)0x20000468 = 0xeb0;
*(uint16_t*)0x2000046a = 0x20;
*(uint16_t*)0x2000046c = 2;
*(uint16_t*)0x2000046e = 0;
*(uint16_t*)0x20000470 = 0;
*(uint16_t*)0x20000472 = 0;
*(uint32_t*)0x20000478 = 0;
*(uint32_t*)0x2000047c = 0;
*(uint32_t*)0x20000480 = 0;
*(uint32_t*)0x20000484 = 0;
*(uint32_t*)0x20000488 = 0;
*(uint32_t*)0x2000048c = 0;
*(uint32_t*)0x20000490 = 0;
*(uint32_t*)0x20000494 = 0;
memset((void*)0x20000498, 0, 256);
memset((void*)0x20000598, 0, 256);
memset((void*)0x20000698, 0, 256);
memset((void*)0x20000798, 0, 256);
memset((void*)0x20000898, 0, 256);
memset((void*)0x20000998, 0, 256);
memset((void*)0x20000a98, 0, 256);
syscall(__NR_write, /*fd=*/r[0],
/*data=*/0x20000440ul, /*len=*/0x758ul);
break;
case 2:
syscall(__NR_close, /*fd=*/r[0]);
break;
case 3:
memcpy((void*)0x20000000, "/dev/vhost-net\000", 15);
res = syscall(__NR_openat,
/*fd=*/0xffffffffffffff9cul, /*file=*/0x20000000ul, /*flags=*/2ul,
/*mode=*/0ul);
if (res != -1)
r[1] = res;
break;
case 4:
syscall(__NR_ioctl, /*fd=*/r[1], /*cmd=*/0xaf01, /*v=*/0ul);
break;
case 5:
memcpy((void*)0x20000400, "./file0\000", 8);
syscall(__NR_execve, /*file=*/0x20000400ul,
/*argv=*/0ul, /*envp=*/0ul);
break;
}
}
int main(void)
{
syscall(__NR_mmap, /*addr=*/0x1ffff000ul,
/*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1,
/*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x20000000ul,
/*len=*/0x1000000ul, /*prot=*/7ul, /*flags=*/0x32ul, /*fd=*/-1,
/*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul,
/*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
loop();
return 0;
}
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2023-11-21 14:33 [syzbot] [kernel?] KASAN: slab-use-after-free Read in kill_orphaned_pgrp syzbot
2023-11-22 6:13 xingwei lee
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