From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A51C1C4332F for ; Mon, 12 Dec 2022 08:07:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231328AbiLLIH6 (ORCPT ); Mon, 12 Dec 2022 03:07:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230079AbiLLIH5 (ORCPT ); Mon, 12 Dec 2022 03:07:57 -0500 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB980617D for ; Mon, 12 Dec 2022 00:07:55 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id 3-20020a17090a098300b00219041dcbe9so11333015pjo.3 for ; Mon, 12 Dec 2022 00:07:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=nf9ayQtLEfleJnUHuiiptUAQglaL8ZyhrXYCYKuEI1A=; b=EQ5TEiYs1AIPKkSuPJ/6Qle9IB8r5HySrAAlsrscsuD8zzeMsBDqdITCjcheObvm5H wHNz1k4oTlFJdsVGhfvFoSgvWrpOKHddTsLypLXDMcZqP3uwjNssJ1mqPByyp27nuWFw J+MvTJWGIEEWWaqbIGV70ZLKMahpqWTpxd/wds6J3ZA7khy4Tl3FsGicOLe6ninBPIgO kFpd23eR1eymHPJYSWZz9pS62chphvMDOTxdBkUK9v/yFz/eT4DqdjXoIP1xjxu+5ewz pynbMLMNP/a23kJgjDK58CTrawG+e4r2ow4483rMnI81CT2uf+vIUOPOuozCcPObhpqV h7mQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=nf9ayQtLEfleJnUHuiiptUAQglaL8ZyhrXYCYKuEI1A=; b=ggessZn8XAQNtD6hEqQC9wcfiLNT3QiHRzi+OFJWxsTNrUF1uv7xIefFNVcfFBgMRr VeECvely8HiYshRnx77fVueo7t4zQOYe7O0FU6wKv4vqE9+dQpwrOvH+RsX/nrE8gg5R d8rIC+OFK0DqsuEVNzGJ7Vc+PNcdPPG1bfKFr3m75S1O2LBIzxIO66DlUW8Rwq4dTZxN wd9ptUAfw2ePQtuTvOmpN7EEskfuiLJhdVo137yX0089qvihG2ru6a/GBgv6FFIOs3i1 9NH4eDaqg45apmLn9/qOfKmjR4XwYrESoHTmT7Q0kBE12r2VAgSCAq/+c83JwjVggrjr vWQA== X-Gm-Message-State: ANoB5pl271jOLd04YyxzWPFhNKwvWraJdjkHQ4xUYzo3j1dv2aPxETeU 20JSx82sG+cTo9mqwNbjmogFvJb5nB5mOWYKWzH2wmEg+yjzDg== X-Google-Smtp-Source: AA0mqf4D9ss+qx7BHZrkFUmhbD3dyaOA+Plu+j3obRZ75qr7XgRp6MrWC2Xx+kMAmEdvzlSmw6HawZnhnj6+rtiJXag= X-Received: by 2002:a17:90a:70cb:b0:219:bef2:8fb3 with SMTP id a11-20020a17090a70cb00b00219bef28fb3mr24856465pjm.66.1670832474589; Mon, 12 Dec 2022 00:07:54 -0800 (PST) MIME-Version: 1.0 From: Gerald Lee Date: Mon, 12 Dec 2022 16:07:43 +0800 Message-ID: Subject: usb: A use-after-free Write in put_dev To: linux-usb@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Hi, all I found a vulnerability when fuzzing linux kernel by syzkaller. The KASAN reports that use-after-free Write in put_dev. Then I tried to reproduce and got the C source file. I compiled it and executed the binary program, but the kernel crashed as expected. This vulnerability could be used to LPE as UAF, I thought. ## Linux version: 6.1.0 (master commit a4412fdd49dc011bcc2c0d81ac4cab7457092650) ## KASAN report ================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:102 [inline] BUG: KASAN: use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline] BUG: KASAN: use-after-free in __refcount_sub_and_test include/linux/refcount.h:272 [inline] BUG: KASAN: use-after-free in __refcount_dec_and_test include/linux/refcount.h:315 [inline] BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:333 [inline] BUG: KASAN: use-after-free in put_dev+0x22/0xd0 drivers/usb/gadget/legacy/inode.c:159 Write of size 4 at addr ffff8880436d2040 by task syz-executor.5/7587 CPU: 1 PID: 7587 Comm: syz-executor.5 Not tainted 6.1.0-rc7 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x141/0x190 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:102 [inline] atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline] __refcount_sub_and_test include/linux/refcount.h:272 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] put_dev+0x22/0xd0 drivers/usb/gadget/legacy/inode.c:159 gadgetfs_kill_sb+0x2e/0x60 drivers/usb/gadget/legacy/inode.c:2086 deactivate_locked_super+0x98/0x160 fs/super.c:332 vfs_get_super fs/super.c:1190 [inline] get_tree_single+0x188/0x1d0 fs/super.c:1207 vfs_get_tree+0x8d/0x2f0 fs/super.c:1531 vfs_fsconfig_locked fs/fsopen.c:232 [inline] __do_sys_fsconfig+0x8d6/0xc20 fs/fsopen.c:439 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f8d5129078d Code: c3 e8 17 32 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8d52024bd8 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007f8d513cbf80 RCX: 00007f8d5129078d RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 00007f8d512feb02 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd48293eff R14: 00007ffd48294090 R15: 00007f8d52024d80 Allocated by task 7561: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa5/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:689 [inline] dev_new drivers/usb/gadget/legacy/inode.c:170 [inline] gadgetfs_fill_super+0x1e4/0x460 drivers/usb/gadget/legacy/inode.c:2041 vfs_get_super fs/super.c:1169 [inline] get_tree_single+0xd6/0x1d0 fs/super.c:1207 vfs_get_tree+0x8d/0x2f0 fs/super.c:1531 vfs_fsconfig_locked fs/fsopen.c:232 [inline] __do_sys_fsconfig+0x8d6/0xc20 fs/fsopen.c:439 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798 pwq_unbound_release_workfn+0x26b/0x340 kernel/workqueue.c:3736 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:481 call_rcu+0x9d/0x820 kernel/rcu/tree.c:2798 pwq_unbound_release_workfn+0x26b/0x340 kernel/workqueue.c:3736 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff8880436d2000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 64 bytes inside of 1024-byte region [ffff8880436d2000, ffff8880436d2400) The buggy address belongs to the physical page: page:ffffea00010db400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x436d0 head:ffffea00010db400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000010200 dead000000000100 dead000000000122 ffff888012041dc0 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6599, tgid 6599 (syz-executor.0), ts 29294571719, free_ts 29285126043 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4291 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5558 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa9b/0x13e0 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x199/0x3e0 mm/slub.c:3437 kmalloc_trace+0x26/0x60 mm/slab_common.c:1045 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:689 [inline] batadv_hardif_add_interface net/batman-adv/hard-interface.c:864 [inline] batadv_hard_if_event+0x8a1/0x1450 net/batman-adv/hard-interface.c:952 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] register_netdevice+0x10bf/0x1670 net/core/dev.c:10090 veth_newlink+0x4d1/0x990 drivers/net/veth.c:1795 rtnl_newlink_create net/core/rtnetlink.c:3364 [inline] __rtnl_newlink+0x1084/0x17e0 net/core/rtnetlink.c:3581 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3594 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6091 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x1d/0x4d0 mm/page_alloc.c:3483 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x184/0x210 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x66/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] __kmem_cache_alloc_node+0x2e2/0x3e0 mm/slub.c:3437 kmalloc_trace+0x26/0x60 mm/slab_common.c:1045 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:689 [inline] kset_create lib/kobject.c:937 [inline] kset_create_and_add+0x4f/0x1a0 lib/kobject.c:980 register_queue_kobjects net/core/net-sysfs.c:1766 [inline] netdev_register_kobject+0x1ca/0x400 net/core/net-sysfs.c:2019 register_netdevice+0xd99/0x1670 net/core/dev.c:10057 __ip_tunnel_create+0x398/0x570 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x2ec/0x9f0 net/ipv4/ip_tunnel.c:1073 ops_init+0xb9/0x680 net/core/net_namespace.c:135 setup_net+0x5d1/0xc50 net/core/net_namespace.c:332 copy_net_ns+0x31c/0x760 net/core/net_namespace.c:478 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 Memory state around the buggy address: ffff8880436d1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880436d1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880436d2000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880436d2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880436d2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ## repro.c // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef __NR_fsconfig #define __NR_fsconfig 431 #endif #ifndef __NR_fsopen #define __NR_fsopen 430 #endif static unsigned long long procid; 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 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"); } 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[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; memcpy((void*)0x20000040, "gadgetfs\000", 9); res = syscall(__NR_fsopen, 0x20000040ul, 0ul); if (res != -1) r[0] = res; syscall(__NR_fsconfig, r[0], 6ul, 0ul, 0ul, 0ul); } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); for (procid = 0; procid < 2; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; } ## Some repro steps 1. create qemu image $ wget https://raw.githubusercontent.com/google/syzkaller/master/tools/create-image.sh -O create-image.sh $ chmod +x create-image.sh $ ./create-image.sh --feature full # generate stretch.img 2. run VM $ /usr/bin/qemu-system-x86_64 \ -m 2048 -smp 2 \ -chardev socket,id=SOCKSYZ,server=on,wait=off,host=localhost,port=31337 \ -mon chardev=SOCKSYZ,mode=control \ -display none \ -serial stdio \ -no-reboot -no-hpet -name VM-RP \ -device virtio-rng-pci \ -enable-kvm \ -cpu host,migratable=off \ -device e1000,netdev=net0 \ -netdev user,id=net0,restrict=on,hostfwd=tcp:127.0.0.1:22422-:22 \ -hda stretch.img \ -snapshot \ -kernel /opt/kernel/arch/x86/boot/bzImage \ -append "root=/dev/sda console=ttyS0 earlyprintk=serial hpet=disable" 3. compile repro.c and execute repro $ scp -i stretch.id_rsa -P 22422 -o "StrictHostKeyChecking no" repro.c root@localhost:/root $ ssh -i stretch.id_rsa -p 22422 -o "StrictHostKeyChecking no" root@localhost In guestOS # gcc -o repro repro.c -lpthread # ./repro Thanks.