syzbot has found a reproducer for the following issue on: HEAD commit: 741668ef7832 Merge tag 'usb-5.15-rc5' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=101a9d00b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=76f7496a8217e5ec dashboard link: https://syzkaller.appspot.com/bug?extid=8281086e8a6fbfbd952a compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=170487b7300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8281086e8a6fbfbd952a@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in bdev_free_inode+0x202/0x220 block/bdev.c:407 Read of size 8 at addr ffff88806e022148 by task systemd-udevd/8843 CPU: 1 PID: 8843 Comm: systemd-udevd Not tainted 5.15.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x6c/0x2d6 mm/kasan/report.c:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 bdev_free_inode+0x202/0x220 block/bdev.c:407 i_callback+0x3f/0x70 fs/inode.c:226 rcu_do_batch kernel/rcu/tree.c:2508 [inline] rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2743 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 </IRQ> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x77/0x80 kernel/kcov.c:272 Code: f0 72 27 41 0f b6 fb 41 0f b6 c9 48 83 c2 01 48 c7 44 30 e0 01 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 <5b> c3 0f 1f 80 00 00 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 RSP: 0018:ffffc9000ddef8f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888075942040 RDX: 0000000000000000 RSI: ffff888075942040 RDI: 0000000000000003 RBP: ffff88801e525f00 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff83a9492a R11: 0000000000000010 R12: 0000000000000002 R13: 000000000000010d R14: dffffc0000000000 R15: 0000000000000000 tomoyo_domain_quota_is_ok+0x32a/0x550 security/tomoyo/util.c:1092 tomoyo_supervisor+0x2f2/0xf00 security/tomoyo/common.c:2089 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission security/tomoyo/file.c:587 [inline] tomoyo_path_permission+0x270/0x3a0 security/tomoyo/file.c:573 tomoyo_path_perm+0x2f0/0x400 security/tomoyo/file.c:838 security_inode_getattr+0xcf/0x140 security/security.c:1333 vfs_getattr fs/stat.c:157 [inline] vfs_fstat+0x43/0xb0 fs/stat.c:182 __do_sys_newfstat+0x81/0x100 fs/stat.c:422 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc02b7062e2 Code: 48 8b 05 b9 db 2b 00 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 83 ff 01 77 33 48 63 fe b8 05 00 00 00 48 89 d6 0f 05 <48> 3d 00 f0 ff ff 77 06 f3 c3 0f 1f 40 00 48 8b 15 81 db 2b 00 f7 RSP: 002b:00007fffd25fb168 EFLAGS: 00000246 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 00007fc02b9c1440 RCX: 00007fc02b7062e2 RDX: 00007fffd25fb170 RSI: 00007fffd25fb170 RDI: 0000000000000007 RBP: 000055a86b68e0d0 R08: 00007fc02c8948c0 R09: 0000000000000230 R10: 000055a869f246bb R11: 0000000000000246 R12: 000055a869f246bb R13: 0000000000000002 R14: 00007fc02b9c1440 R15: 0000000000000002 Allocated by task 15227: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa1/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_node_trace+0x20b/0x5d0 mm/slab.c:3619 kmalloc_node include/linux/slab.h:609 [inline] kzalloc_node include/linux/slab.h:732 [inline] __alloc_disk_node+0x77/0x580 block/genhd.c:1238 __blk_mq_alloc_disk+0xed/0x160 block/blk-mq.c:3140 loop_add+0x340/0x960 drivers/block/loop.c:2344 loop_control_get_free drivers/block/loop.c:2501 [inline] loop_control_ioctl+0x227/0x4a0 drivers/block/loop.c:2516 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 15227: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xd1/0x110 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] __cache_free mm/slab.c:3445 [inline] kfree+0x10a/0x2c0 mm/slab.c:3803 __alloc_disk_node+0x474/0x580 block/genhd.c:1275 __blk_mq_alloc_disk+0xed/0x160 block/blk-mq.c:3140 loop_add+0x340/0x960 drivers/block/loop.c:2344 loop_control_get_free drivers/block/loop.c:2501 [inline] loop_control_ioctl+0x227/0x4a0 drivers/block/loop.c:2516 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xa7/0xd0 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x990 kernel/rcu/tree.c:3552 neigh_destroy+0x419/0x620 net/core/neighbour.c:859 neigh_release include/net/neighbour.h:425 [inline] neigh_cleanup_and_release+0x1fd/0x340 net/core/neighbour.c:103 neigh_del net/core/neighbour.c:197 [inline] neigh_remove_one+0x37d/0x460 net/core/neighbour.c:218 neigh_forced_gc net/core/neighbour.c:248 [inline] neigh_alloc net/core/neighbour.c:395 [inline] ___neigh_create+0x1799/0x26b0 net/core/neighbour.c:583 ip6_finish_output2+0x1089/0x1500 net/ipv6/ip6_output.c:123 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x4c1/0x1050 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3893 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 The buggy address belongs to the object at ffff88806e022000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 328 bytes inside of 1024-byte region [ffff88806e022000, ffff88806e022400) The buggy address belongs to the page: page:ffffea0001b80880 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88806e022800 pfn:0x6e022 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00006c07c8 ffffea0000846d88 ffff888010c40700 raw: ffff88806e022800 ffff88806e022000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2c2220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_THISNODE), pid 158, ts 99636399470, free_ts 99492418189 prep_new_page mm/page_alloc.c:2424 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4153 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5375 __alloc_pages_node include/linux/gfp.h:570 [inline] kmem_getpages mm/slab.c:1377 [inline] cache_grow_begin+0x75/0x460 mm/slab.c:2593 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965 ____cache_alloc mm/slab.c:3048 [inline] ____cache_alloc mm/slab.c:3031 [inline] slab_alloc_node mm/slab.c:3249 [inline] kmem_cache_alloc_node_trace+0x4ca/0x5d0 mm/slab.c:3617 __do_kmalloc_node mm/slab.c:3639 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3654 kmalloc_reserve net/core/skbuff.c:355 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1116 [inline] wg_socket_send_buffer_to_peer+0x2f/0x170 drivers/net/wireguard/socket.c:191 wg_packet_send_handshake_initiation+0x212/0x340 drivers/net/wireguard/send.c:40 wg_packet_handshake_send_worker+0x18/0x30 drivers/net/wireguard/send.c:51 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3315 [inline] free_unref_page_list+0x1a9/0xfa0 mm/page_alloc.c:3431 release_pages+0x830/0x20b0 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:242 [inline] tlb_flush_mmu mm/mmu_gather.c:249 [inline] tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:340 exit_mmap+0x1ea/0x630 mm/mmap.c:3173 __mmput+0x122/0x4b0 kernel/fork.c:1115 mmput+0x58/0x60 kernel/fork.c:1136 free_bprm+0x65/0x2e0 fs/exec.c:1483 kernel_execve+0x380/0x460 fs/exec.c:1980 call_usermodehelper_exec_async+0x2e3/0x580 kernel/umh.c:112 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff88806e022000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806e022080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806e022100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806e022180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806e022200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: f0 72 27 lock jb 0x2a 3: 41 0f b6 fb movzbl %r11b,%edi 7: 41 0f b6 c9 movzbl %r9b,%ecx b: 48 83 c2 01 add $0x1,%rdx f: 48 c7 44 30 e0 01 00 movq $0x1,-0x20(%rax,%rsi,1) 16: 00 00 18: 48 89 7c 30 e8 mov %rdi,-0x18(%rax,%rsi,1) 1d: 48 89 4c 30 f0 mov %rcx,-0x10(%rax,%rsi,1) 22: 4c 89 54 d8 20 mov %r10,0x20(%rax,%rbx,8) 27: 48 89 10 mov %rdx,(%rax) * 2a: 5b pop %rbx <-- trapping instruction 2b: c3 retq 2c: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 33: 53 push %rbx 34: 41 89 fb mov %edi,%r11d 37: 41 89 f1 mov %esi,%r9d 3a: bf 03 00 00 00 mov $0x3,%edi 3f: 65 gs
