netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 28 bytes leftover after parsing attributes in process `syz-executor.2'. IPVS: ftp: loaded support on port[0] = 21 ====================================================== WARNING: possible circular locking dependency detected 4.14.276-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/11850 is trying to acquire lock: (sb_writers#6){.+.+}, at: [] file_start_write include/linux/fs.h:2714 [inline] (sb_writers#6){.+.+}, at: [] vfs_fallocate+0x5c1/0x790 fs/open.c:318 but task is already holding lock: (ashmem_mutex){+.+.}, at: [] ashmem_shrink_scan drivers/staging/android/ashmem.c:494 [inline] (ashmem_mutex){+.+.}, at: [] ashmem_ioctl+0x27e/0xd00 drivers/staging/android/ashmem.c:843 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (ashmem_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 ashmem_mmap+0x50/0x5c0 drivers/staging/android/ashmem.c:393 call_mmap include/linux/fs.h:1785 [inline] mmap_region+0xa1a/0x1220 mm/mmap.c:1717 do_mmap+0x5b3/0xcb0 mm/mmap.c:1495 do_mmap_pgoff include/linux/mm.h:2185 [inline] vm_mmap_pgoff+0x14e/0x1a0 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1545 [inline] SyS_mmap_pgoff+0x249/0x510 mm/mmap.c:1503 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #2 (&mm->mmap_sem){++++}: __might_fault mm/memory.c:4700 [inline] __might_fault+0x137/0x1b0 mm/memory.c:4685 _copy_to_user+0x27/0xd0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] filldir+0x1d5/0x390 fs/readdir.c:237 dir_emit_dot include/linux/fs.h:3361 [inline] dir_emit_dots include/linux/fs.h:3372 [inline] dcache_readdir+0x180/0x860 fs/libfs.c:192 iterate_dir+0x1a0/0x5e0 fs/readdir.c:52 SYSC_getdents fs/readdir.c:272 [inline] SyS_getdents+0x125/0x240 fs/readdir.c:253 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (&type->i_mutex_dir_key#5){++++}: down_write+0x34/0x90 kernel/locking/rwsem.c:54 inode_lock include/linux/fs.h:719 [inline] do_last fs/namei.c:3331 [inline] path_openat+0xde2/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (sb_writers#6){.+.+}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x64/0x260 fs/super.c:1342 file_start_write include/linux/fs.h:2714 [inline] vfs_fallocate+0x5c1/0x790 fs/open.c:318 ashmem_shrink_scan.part.0+0x135/0x3d0 drivers/staging/android/ashmem.c:501 ashmem_shrink_scan drivers/staging/android/ashmem.c:494 [inline] ashmem_ioctl+0x294/0xd00 drivers/staging/android/ashmem.c:843 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: sb_writers#6 --> &mm->mmap_sem --> ashmem_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(ashmem_mutex); lock(&mm->mmap_sem); lock(ashmem_mutex); lock(sb_writers#6); *** DEADLOCK *** 1 lock held by syz-executor.3/11850: #0: (ashmem_mutex){+.+.}, at: [] ashmem_shrink_scan drivers/staging/android/ashmem.c:494 [inline] #0: (ashmem_mutex){+.+.}, at: [] ashmem_ioctl+0x27e/0xd00 drivers/staging/android/ashmem.c:843 stack backtrace: CPU: 0 PID: 11850 Comm: syz-executor.3 Not tainted 4.14.276-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x64/0x260 fs/super.c:1342 file_start_write include/linux/fs.h:2714 [inline] vfs_fallocate+0x5c1/0x790 fs/open.c:318 ashmem_shrink_scan.part.0+0x135/0x3d0 drivers/staging/android/ashmem.c:501 ashmem_shrink_scan drivers/staging/android/ashmem.c:494 [inline] ashmem_ioctl+0x294/0xd00 drivers/staging/android/ashmem.c:843 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f4d30a8e0e9 RSP: 002b:00007f4d2f3e2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4d30ba1030 RCX: 00007f4d30a8e0e9 RDX: 0000000000000000 RSI: 000000000000770a RDI: 0000000000000003 RBP: 00007f4d30ae808d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe1fe914ef R14: 00007f4d2f3e2300 R15: 0000000000022000 Zero length message leads to an empty skb audit: type=1804 audit(1650726624.515:3): pid=12009 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir611788412/syzkaller.UQYMmr/163/bus" dev="sda1" ino=14178 res=1 audit: type=1804 audit(1650726624.575:4): pid=12015 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.3" name="/root/syzkaller-testdir611788412/syzkaller.UQYMmr/163/bus" dev="sda1" ino=14178 res=1 audit: type=1804 audit(1650726624.635:5): pid=12015 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir611788412/syzkaller.UQYMmr/163/bus" dev="sda1" ino=14178 res=1 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 12015 Comm: syz-executor.3 Not tainted 4.14.276-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888099930540 task.stack: ffff888044678000 RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:167 [inline] RIP: 0010:rb_erase+0x29/0x1290 lib/rbtree.c:459 RSP: 0018:ffff88804467fa68 EFLAGS: 00010292 RAX: dffffc0000000000 RBX: ffff8880575a52f0 RCX: ffffc90009603000 RDX: 0000000000000001 RSI: ffffffff8bfafea0 RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888099930540 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff8880516299f8 R15: ffffffff8bfafea0 FS: 00007f4d2f3e2700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555728a708 CR3: 00000000a951f000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: integrity_inode_free+0x119/0x300 security/integrity/iint.c:146 security_inode_free+0x14/0x80 security/security.c:443 __destroy_inode+0x1e8/0x4d0 fs/inode.c:238 destroy_inode+0x49/0x110 fs/inode.c:265 iput_final fs/inode.c:1524 [inline] iput+0x458/0x7e0 fs/inode.c:1551 swap_inode_boot_loader fs/ext4/ioctl.c:197 [inline] ext4_ioctl+0x12e1/0x3800 fs/ext4/ioctl.c:924 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f4d30a8e0e9 RSP: 002b:00007f4d2f3e2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4d30ba1030 RCX: 00007f4d30a8e0e9 RDX: 0000000000000000 RSI: 0000000000006611 RDI: 0000000000000003 RBP: 00007f4d30ae808d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe1fe914ef R14: 00007f4d2f3e2300 R15: 0000000000022000 Code: ff ff 48 b8 00 00 00 00 00 fc ff df 41 57 49 89 f7 41 56 41 55 41 54 49 89 fc 48 83 c7 08 48 89 fa 55 48 c1 ea 03 53 48 83 ec 18 <80> 3c 02 00 0f 85 f2 0c 00 00 49 8d 7c 24 10 4d 8b 74 24 08 48 RIP: __rb_erase_augmented include/linux/rbtree_augmented.h:167 [inline] RSP: ffff88804467fa68 RIP: rb_erase+0x29/0x1290 lib/rbtree.c:459 RSP: ffff88804467fa68 ---[ end trace 7b06cc2dbb711e92 ]--- ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 7: fc ff df a: 41 57 push %r15 c: 49 89 f7 mov %rsi,%r15 f: 41 56 push %r14 11: 41 55 push %r13 13: 41 54 push %r12 15: 49 89 fc mov %rdi,%r12 18: 48 83 c7 08 add $0x8,%rdi 1c: 48 89 fa mov %rdi,%rdx 1f: 55 push %rbp 20: 48 c1 ea 03 shr $0x3,%rdx 24: 53 push %rbx 25: 48 83 ec 18 sub $0x18,%rsp * 29: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2d: 0f 85 f2 0c 00 00 jne 0xd25 33: 49 8d 7c 24 10 lea 0x10(%r12),%rdi 38: 4d 8b 74 24 08 mov 0x8(%r12),%r14 3d: 48 rex.W