Messages in this thread | | | From | Andrey Konovalov <> | Date | Sat, 3 Dec 2016 16:39:41 +0100 | Subject | Re: net: use-after-free in worker_thread |
| |
On Sat, Dec 3, 2016 at 2:49 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote: > On Sat, 2016-12-03 at 14:05 +0100, Andrey Konovalov wrote: >> On Sat, Dec 3, 2016 at 1:58 PM, Andrey Konovalov <andreyknvl@google.com> wrote: >> > +syzkaller@googlegroups.com >> > >> > On Sat, Dec 3, 2016 at 1:56 PM, Andrey Konovalov <andreyknvl@google.com> wrote: >> >> Hi! >> >> >> >> I'm seeing lots of the following error reports while running the >> >> syzkaller fuzzer. >> >> >> >> Reports appeared when I updated to 3c49de52 (Dec 2) from 2caceb32 (Dec 1). >> >> >> >> ================================================================== >> >> BUG: KASAN: use-after-free in worker_thread+0x17d8/0x18a0 >> >> Read of size 8 at addr ffff880067f3ecd8 by task kworker/3:1/774 >> >> >> >> page:ffffea00019fce00 count:1 mapcount:0 mapping: (null) >> >> index:0xffff880067f39c10 compound_mapcount: 0 >> >> flags: 0x500000000004080(slab|head) >> >> page dumped because: kasan: bad access detected >> >> >> >> CPU: 3 PID: 774 Comm: kworker/3:1 Not tainted 4.9.0-rc7+ #66 >> >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> >> ffff88006c267838 ffffffff81f882da ffffffff6c25e338 1ffff1000d84ce9a >> >> ffffed000d84ce92 ffff88006c25e340 0000000041b58ab3 ffffffff8541e198 >> >> ffffffff81f88048 0000000100000000 0000000041b58ab3 ffffffff853d3ee8 >> >> Call Trace: >> >> [< inline >] __dump_stack lib/dump_stack.c:15 >> >> [<ffffffff81f882da>] dump_stack+0x292/0x398 lib/dump_stack.c:51 >> >> [< inline >] describe_address mm/kasan/report.c:262 >> >> [<ffffffff817e50d1>] kasan_report_error+0x121/0x560 mm/kasan/report.c:368 >> >> [< inline >] kasan_report mm/kasan/report.c:390 >> >> [<ffffffff817e560e>] __asan_report_load8_noabort+0x3e/0x40 >> >> mm/kasan/report.c:411 >> >> [<ffffffff81329b88>] worker_thread+0x17d8/0x18a0 kernel/workqueue.c:2228 >> >> [<ffffffff8133ebf3>] kthread+0x323/0x3e0 kernel/kthread.c:209 >> >> [<ffffffff84a2a22a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 >> >> >> >> The buggy address belongs to the object at ffff880067f3e6d0 >> >> which belongs to the cache kmalloc-2048 of size 2048 >> >> The buggy address ffff880067f3ecd8 is located 1544 bytes inside >> >> of 2048-byte region [ffff880067f3e6d0, ffff880067f3eed0) >> >> >> >> Freed by task 0: >> >> [<ffffffff81203526>] save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> >> [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 >> >> [< inline >] set_track mm/kasan/kasan.c:507 >> >> [<ffffffff817e4a53>] kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:571 >> >> [< inline >] slab_free_hook mm/slub.c:1352 >> >> [< inline >] slab_free_freelist_hook mm/slub.c:1374 >> >> [< inline >] slab_free mm/slub.c:2951 >> >> [<ffffffff817e0eb7>] kfree+0xe7/0x2b0 mm/slub.c:3871 >> >> [< inline >] sk_prot_free net/core/sock.c:1372 >> >> [<ffffffff831ea1c7>] __sk_destruct+0x5c7/0x6e0 net/core/sock.c:1445 >> >> [<ffffffff831f3517>] sk_destruct+0x47/0x80 net/core/sock.c:1453 >> >> [<ffffffff831f35a7>] __sk_free+0x57/0x230 net/core/sock.c:1461 >> >> [<ffffffff831f37a3>] sk_free+0x23/0x30 net/core/sock.c:1472 >> >> [< inline >] sock_put include/net/sock.h:1591 >> >> [<ffffffff8348ca9c>] deferred_put_nlk_sk+0x2c/0x40 net/netlink/af_netlink.c:671 >> >> [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118 >> >> [<ffffffff8146d42f>] rcu_do_batch.isra.67+0x8ff/0xc50 kernel/rcu/tree.c:2776 >> >> [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3040 >> >> [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3007 >> >> [<ffffffff8146e097>] rcu_process_callbacks+0x2b7/0xba0 kernel/rcu/tree.c:3024 >> >> [<ffffffff84a2d08b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284 >> >> >> >> Allocated by task 10748: >> >> [<ffffffff81203526>] save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> >> [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 >> >> [< inline >] set_track mm/kasan/kasan.c:507 >> >> [<ffffffff817e43fd>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:598 >> >> [<ffffffff817e0050>] __kmalloc+0xa0/0x2d0 mm/slub.c:3734 >> >> [< inline >] kmalloc include/linux/slab.h:495 >> >> [<ffffffff831e4c01>] sk_prot_alloc+0x101/0x2a0 net/core/sock.c:1333 >> >> [<ffffffff831efd15>] sk_alloc+0x105/0x1000 net/core/sock.c:1389 >> >> [<ffffffff8348ad46>] __netlink_create+0x66/0x1d0 net/netlink/af_netlink.c:588 >> >> [<ffffffff8348cdab>] netlink_create+0x2fb/0x500 net/netlink/af_netlink.c:647 >> >> [<ffffffff831dd1d6>] __sock_create+0x4f6/0x880 net/socket.c:1168 >> >> [< inline >] sock_create net/socket.c:1208 >> >> [< inline >] SYSC_socket net/socket.c:1238 >> >> [<ffffffff831dd799>] SyS_socket+0xf9/0x230 net/socket.c:1218 >> >> [<ffffffff84a29fc1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 >> >> >> >> Memory state around the buggy address: >> >> ffff880067f3eb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ffff880067f3ec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >>>ffff880067f3ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ^ >> >> ffff880067f3ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ffff880067f3ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ================================================================== >> >> Here is another report that looks related: >> >> ================================================================== >> BUG: KASAN: use-after-free in __list_add+0x236/0x2c0 >> Read of size 8 at addr ffff880068854780 by task ksoftirqd/2/20 >> >> page:ffffea0001a21400 count:1 mapcount:0 mapping: (null) >> index:0x0 compound_mapcount: 0 >> flags: 0x500000000004080(slab|head) >> page dumped because: kasan: bad access detected >> >> CPU: 2 PID: 20 Comm: ksoftirqd/2 Not tainted 4.9.0-rc7+ #66 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> ffff88006daf6578 ffffffff81f882da ffffffff6daf62a0 1ffff1000db5ec42 >> ffffed000db5ec3a dffffc0000000000 0000000041b58ab3 ffffffff8541e198 >> ffffffff81f88048 ffff88006dac3610 ffff88006daf6300 0000000000000802 >> Call Trace: >> [< inline >] __dump_stack lib/dump_stack.c:15 >> [<ffffffff81f882da>] dump_stack+0x292/0x398 lib/dump_stack.c:51 >> [< inline >] describe_address mm/kasan/report.c:262 >> [<ffffffff817e50d1>] kasan_report_error+0x121/0x560 mm/kasan/report.c:368 >> [< inline >] kasan_report mm/kasan/report.c:390 >> [<ffffffff817e560e>] __asan_report_load8_noabort+0x3e/0x40 >> mm/kasan/report.c:411 >> [<ffffffff8200c166>] __list_add+0x236/0x2c0 lib/list_debug.c:30 >> [< inline >] list_add_tail include/linux/list.h:77 >> [<ffffffff8131e295>] insert_work+0x175/0x4b0 kernel/workqueue.c:1298 >> [<ffffffff8131eb52>] __queue_work+0x582/0x11e0 kernel/workqueue.c:1459 >> [<ffffffff81320c21>] queue_work_on+0x231/0x240 kernel/workqueue.c:1484 >> [< inline >] queue_work include/linux/workqueue.h:474 >> [< inline >] schedule_work include/linux/workqueue.h:532 >> [<ffffffff8348c8cc>] netlink_sock_destruct+0x23c/0x2d0 >> net/netlink/af_netlink.c:361 >> [<ffffffff831e9ce1>] __sk_destruct+0xe1/0x6e0 net/core/sock.c:1423 >> [<ffffffff831f3517>] sk_destruct+0x47/0x80 net/core/sock.c:1453 >> [<ffffffff831f35a7>] __sk_free+0x57/0x230 net/core/sock.c:1461 >> [<ffffffff831f37a3>] sk_free+0x23/0x30 net/core/sock.c:1472 >> [< inline >] sock_put include/net/sock.h:1591 >> [<ffffffff8348ca9c>] deferred_put_nlk_sk+0x2c/0x40 net/netlink/af_netlink.c:671 >> [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118 >> [<ffffffff8146d42f>] rcu_do_batch.isra.67+0x8ff/0xc50 kernel/rcu/tree.c:2776 >> [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3040 >> [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3007 >> [<ffffffff8146e097>] rcu_process_callbacks+0x2b7/0xba0 kernel/rcu/tree.c:3024 >> [<ffffffff84a2d08b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284 >> [<ffffffff812d38c0>] run_ksoftirqd+0x20/0x60 kernel/softirq.c:676 >> [<ffffffff81350132>] smpboot_thread_fn+0x562/0x860 kernel/smpboot.c:163 >> [<ffffffff8133ebf3>] kthread+0x323/0x3e0 kernel/kthread.c:209 >> [<ffffffff84a2a22a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 >> >> The buggy address belongs to the object at ffff880068854170 >> which belongs to the cache kmalloc-2048 of size 2048 >> The buggy address ffff880068854780 is located 1552 bytes inside >> of 2048-byte region [ffff880068854170, ffff880068854970) >> >> Freed by task 20: >> [<ffffffff81203526>] save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 >> [< inline >] set_track mm/kasan/kasan.c:507 >> [<ffffffff817e4a53>] kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:571 >> [< inline >] slab_free_hook mm/slub.c:1352 >> [< inline >] slab_free_freelist_hook mm/slub.c:1374 >> [< inline >] slab_free mm/slub.c:2951 >> [<ffffffff817e0eb7>] kfree+0xe7/0x2b0 mm/slub.c:3871 >> [< inline >] sk_prot_free net/core/sock.c:1372 >> [<ffffffff831ea1c7>] __sk_destruct+0x5c7/0x6e0 net/core/sock.c:1445 >> [<ffffffff831f3517>] sk_destruct+0x47/0x80 net/core/sock.c:1453 >> [<ffffffff831f35a7>] __sk_free+0x57/0x230 net/core/sock.c:1461 >> [<ffffffff831f37a3>] sk_free+0x23/0x30 net/core/sock.c:1472 >> [< inline >] sock_put include/net/sock.h:1591 >> [<ffffffff8348ca9c>] deferred_put_nlk_sk+0x2c/0x40 net/netlink/af_netlink.c:671 >> [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118 >> [<ffffffff8146d42f>] rcu_do_batch.isra.67+0x8ff/0xc50 kernel/rcu/tree.c:2776 >> [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3040 >> [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3007 >> [<ffffffff8146e097>] rcu_process_callbacks+0x2b7/0xba0 kernel/rcu/tree.c:3024 >> [<ffffffff84a2d08b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284 >> >> Allocated by task 9480: >> [<ffffffff81203526>] save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 >> [<ffffffff817e4173>] save_stack+0x43/0xd0 mm/kasan/kasan.c:495 >> [< inline >] set_track mm/kasan/kasan.c:507 >> [<ffffffff817e43fd>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:598 >> [<ffffffff817e0050>] __kmalloc+0xa0/0x2d0 mm/slub.c:3734 >> [< inline >] kmalloc include/linux/slab.h:495 >> [<ffffffff831e4c01>] sk_prot_alloc+0x101/0x2a0 net/core/sock.c:1333 >> [<ffffffff831efd15>] sk_alloc+0x105/0x1000 net/core/sock.c:1389 >> [<ffffffff8348ad46>] __netlink_create+0x66/0x1d0 net/netlink/af_netlink.c:588 >> [<ffffffff8348cdab>] netlink_create+0x2fb/0x500 net/netlink/af_netlink.c:647 >> [<ffffffff831dd1d6>] __sock_create+0x4f6/0x880 net/socket.c:1168 >> [< inline >] sock_create net/socket.c:1208 >> [< inline >] SYSC_socket net/socket.c:1238 >> [<ffffffff831dd799>] SyS_socket+0xf9/0x230 net/socket.c:1218 >> [<ffffffff84a29fc1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 >> >> Memory state around the buggy address: >> ffff880068854680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff880068854700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >ffff880068854780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ^ >> ffff880068854800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff880068854880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ================================================================== > > > Hi Andrey. Please give us some rest during the week end ;)
Hi Eric,
Sorry, wanted to restart fuzzer on newer kernel and immediately started getting enormous amount of crashes :)
> > This looks like the bug I mentioned earlier for which I have a pending > patch ? Can you try it ?
No, it seems that your patch doesn't help, this is apparently something else.
I've attached a reproducer.
Thanks!
> > The RCU conversion done by Thomas was quite buggy. > > Thanks. > > > diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c > index 602e5ebe9db39ec6c72708628bc48efad9f0e680..c348c4a5ea4ecc05dcc9e2afbc069ab65a1a57fe 100644 > --- a/net/netlink/af_netlink.c > +++ b/net/netlink/af_netlink.c > @@ -475,8 +475,8 @@ static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) > > rcu_read_lock(); > sk = __netlink_lookup(table, portid, net); > - if (sk) > - sock_hold(sk); > + if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) > + sk = NULL; > rcu_read_unlock(); > > return sk; > @@ -600,6 +600,7 @@ static int __netlink_create(struct net *net, struct socket *sock, > } > init_waitqueue_head(&nlk->wait); > > + sock_set_flag(sk, SOCK_RCU_FREE); > sk->sk_destruct = netlink_sock_destruct; > sk->sk_protocol = protocol; > return 0; > @@ -664,13 +665,6 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol, > goto out; > } > > -static void deferred_put_nlk_sk(struct rcu_head *head) > -{ > - struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); > - > - sock_put(&nlk->sk); > -} > - > static int netlink_release(struct socket *sock) > { > struct sock *sk = sock->sk; > @@ -743,7 +737,7 @@ static int netlink_release(struct socket *sock) > local_bh_disable(); > sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); > local_bh_enable(); > - call_rcu(&nlk->rcu, deferred_put_nlk_sk); > + sock_put(sk); > return 0; > } > > diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h > index 4fdb3831897775547f77c069a8018c0d2a253c8c..988d1a02487e37b7efd4872dd0ab6d230e5a2021 100644 > --- a/net/netlink/af_netlink.h > +++ b/net/netlink/af_netlink.h > @@ -33,7 +33,6 @@ struct netlink_sock { > struct module *module; > > struct rhash_head node; > - struct rcu_head rcu; > struct work_struct work; > }; > > > > > -- > You received this message because you are subscribed to the Google Groups "syzkaller" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+unsubscribe@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. // autogenerated by syzkaller (http://github.com/google/syzkaller)
#ifndef __NR_socket #define __NR_socket 41 #endif #ifndef __NR_write #define __NR_write 1 #endif #ifndef __NR_readv #define __NR_readv 19 #endif #ifndef __NR_mmap #define __NR_mmap 9 #endif
#define _GNU_SOURCE
#include <sys/ioctl.h> #include <sys/mount.h> #include <sys/prctl.h> #include <sys/resource.h> #include <sys/socket.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/time.h> #include <sys/types.h> #include <sys/wait.h>
#include <linux/capability.h> #include <linux/if.h> #include <linux/if_tun.h> #include <linux/sched.h> #include <net/if_arp.h>
#include <assert.h> #include <dirent.h> #include <errno.h> #include <fcntl.h> #include <grp.h> #include <pthread.h> #include <setjmp.h> #include <signal.h> #include <stdarg.h> #include <stdbool.h> #include <stddef.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h>
const int kFailStatus = 67; const int kErrorStatus = 68; const int kRetryStatus = 69;
__attribute__((noreturn)) void fail(const char* msg, ...) { int e = errno; fflush(stdout); va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); exit(kFailStatus); }
__attribute__((noreturn)) void exitf(const char* msg, ...) { int e = errno; fflush(stdout); va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); exit(kRetryStatus); }
static int flag_debug;
void debug(const char* msg, ...) { if (!flag_debug) return; va_list args; va_start(args, msg); vfprintf(stdout, msg, args); va_end(args); fflush(stdout); }
__thread int skip_segv; __thread jmp_buf segv_env;
static void segv_handler(int sig, siginfo_t* info, void* uctx) { if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED)) _longjmp(segv_env, 1); exit(sig); }
static void install_segv_handler() { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); }
#define NONFAILING(...) \ { \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ }
static uintptr_t execute_syscall(int nr, uintptr_t a0, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4, uintptr_t a5, uintptr_t a6, uintptr_t a7, uintptr_t a8) { switch (nr) { default: return syscall(nr, a0, a1, a2, a3, a4, a5); } }
static void setup_main_process(uint64_t pid, bool enable_tun) { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); install_segv_handler();
char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); }
static void loop();
static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid();
struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim);
unshare(CLONE_NEWNS); unshare(CLONE_NEWIPC); unshare(CLONE_IO); }
static int do_sandbox_none() { int pid = fork(); if (pid) return pid; sandbox_common(); loop(); exit(1); }
static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting"); } exitf("opendir(%s) failed", dir); } while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); struct stat st; if (lstat(filename, &st)) exitf("lstat(%s) failed", filename); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { debug("unlink(%s)\n", filename); if (unlink(filename) == 0) break; if (errno == EROFS) { debug("ignoring EROFS\n"); break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); debug("umount(%s)\n", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); int i; for (i = 0;; i++) { debug("rmdir(%s)\n", dir); if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { debug("ignoring EROFS\n"); break; } if (errno == EBUSY) { debug("umount(%s)\n", dir); if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exitf("rmdir(%s) failed", dir); } }
static uint64_t current_time_ms() { struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed"); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; }
static void test();
void loop() { int iter; for (iter = 0;; iter++) { char cwdbuf[256]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) fail("failed to mkdir"); int pid = fork(); if (pid < 0) fail("clone failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); test(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(pid, &status, __WALL | WNOHANG); int errno0 = errno; if (res == pid) break; usleep(1000); if (current_time_ms() - start > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); waitpid(pid, &status, __WALL); break; } } remove_dir(cwdbuf); } }
long r[7]; void* thr(void* arg) { switch ((long)arg) { case 0: r[0] = execute_syscall(__NR_mmap, 0x20000000ul, 0xe43000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul, 0, 0, 0); break; case 1: r[1] = execute_syscall(__NR_socket, 0x10ul, 0x3ul, 0x0ul, 0, 0, 0, 0, 0, 0); break; case 2: NONFAILING(memcpy((void*)0x20e42fe1, "\x1f\x00\x00\x00\x1a\x00\x03\xf2\x00\x00\x13\xff" "\x07\x00\x00\x77\x00\x00\xff\xff\xff\x7f\xd8\x00" "\x00\x00\x00\x00\x00\x00\x34", 31)); r[3] = execute_syscall(__NR_write, r[1], 0x20e42fe1ul, 0x1ful, 0, 0, 0, 0, 0, 0); break; case 3: NONFAILING(*(uint64_t*)0x20e41000 = (uint64_t)0x20e3ef11); NONFAILING(*(uint64_t*)0x20e41008 = (uint64_t)0x1); r[6] = execute_syscall(__NR_readv, r[1], 0x20e41000ul, 0x1ul, 0, 0, 0, 0, 0, 0); break; } return 0; }
void test() { long i; pthread_t th[8];
memset(r, -1, sizeof(r)); srand(getpid()); for (i = 0; i < 4; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(10000); } usleep(100000); }
int main() { setup_main_process(0, false); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }
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