====================================================== WARNING: possible circular locking dependency detected 4.14.276-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/9905 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.1/9905: #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: 1 PID: 9905 Comm: syz-executor.1 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: 0033:0x7f5de9c6e0e9 RSP: 002b:00007f5de85e3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5de9d80f60 RCX: 00007f5de9c6e0e9 RDX: 0000000000000000 RSI: 000000000000770a RDI: 0000000000000005 RBP: 00007f5de9cc808d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd19ae612f R14: 00007f5de85e3300 R15: 0000000000022000 L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. BTRFS: device fsid 1ad3f776-ab8b-4799-9a00-a78524687b00 devid 1 transid 7 /dev/loop1 BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch BTRFS error (device loop1): open_ctree failed loop3: p2 < > p3 p4 loop3: p3 size 1912633224 extends beyond EOD, truncated BTRFS error (device loop1): unsupported checksum algorithm 2 loop3: p4 size 3657465856 extends beyond EOD, truncated loop3: p2 < > p3 p4 loop3: p3 size 1912633224 extends beyond EOD, truncated BTRFS error (device loop1): superblock checksum mismatch loop3: p4 size 3657465856 extends beyond EOD, truncated unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 BTRFS error (device loop1): open_ctree failed loop3: p2 < > p3 p4 loop3: p3 size 1912633224 extends beyond EOD, truncated loop3: p4 size 3657465856 extends beyond EOD, truncated BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch loop0: p2 < > p3 p4 BTRFS error (device loop1): open_ctree failed loop0: p3 size 1912633224 extends beyond EOD, truncated loop0: p4 size 3657465856 extends beyond EOD, truncated loop5: p2 < > p3 p4 loop4: p2 < > p3 p4 loop3: p2 < > p3 p4 loop2: p2 < > p3 p4 loop5: p3 size 1912633224 extends beyond EOD, truncated BTRFS error (device loop1): unsupported checksum algorithm 2 BTRFS error (device loop1): superblock checksum mismatch loop3: p3 size 1912633224 extends beyond EOD, truncated loop2: p3 size 1912633224 extends beyond EOD, truncated loop4: p3 size 1912633224 extends beyond EOD, truncated BTRFS error (device loop1): open_ctree failed loop0: p2 < > p3 p4 loop5: p4 size 3657465856 extends beyond EOD, truncated loop4: p4 size 3657465856 extends beyond EOD, truncated loop0: p3 size 1912633224 extends beyond EOD, truncated loop3: p4 size 3657465856 extends beyond EOD, truncated loop2: p4 size 3657465856 extends beyond EOD, truncated loop0: p4 size 3657465856 extends beyond EOD, truncated loop3: p2 < > p3 p4 loop4: p2 < > p3 p4 loop1: p2 < > p3 p4 loop5: p2 < > p3 p4 loop0: p2 < > p3 p4 loop3: p3 size 1912633224 extends beyond EOD, truncated loop2: p2 < > p3 p4 loop4: p3 size 1912633224 extends beyond EOD, truncated loop1: p3 size 1912633224 extends beyond EOD, truncated loop5: p3 size 1912633224 extends beyond EOD, truncated loop3: p4 size 3657465856 extends beyond EOD, truncated loop0: p3 size 1912633224 extends beyond EOD, truncated loop1: p4 size 3657465856 extends beyond EOD, truncated loop2: p3 size 1912633224 extends beyond EOD, truncated loop5: p4 size 3657465856 extends beyond EOD, truncated loop4: p4 size 3657465856 extends beyond EOD, truncated loop0: p4 size 3657465856 extends beyond EOD, truncated loop2: p4 size 3657465856 extends beyond EOD, truncated loop4: p2 < > p3 p4 loop4: p3 size 1912633224 extends beyond EOD, truncated loop4: p4 size 3657465856 extends beyond EOD, truncated loop_reread_partitions: partition scan of loop2 () failed (rc=-16) print_req_error: I/O error, dev loop2, sector 264033 print_req_error: I/O error, dev loop2, sector 264064 print_req_error: I/O error, dev loop2, sector 264033 Buffer I/O error on dev loop2p3, logical block 263808, async page read print_req_error: I/O error, dev loop2, sector 264064 Buffer I/O error on dev loop2p4, logical block 33008, async page read print_req_error: I/O error, dev loop2, sector 264034 Buffer I/O error on dev loop2p3, logical block 263809, async page read print_req_error: I/O error, dev loop2, sector 264035 Buffer I/O error on dev loop2p3, logical block 263810, async page read print_req_error: I/O error, dev loop2, sector 264036 Buffer I/O error on dev loop2p3, logical block 263811, async page read print_req_error: I/O error, dev loop2, sector 264037 Buffer I/O error on dev loop2p3, logical block 263812, async page read print_req_error: I/O error, dev loop2, sector 264038 Buffer I/O error on dev loop2p3, logical block 263813, async page read print_req_error: I/O error, dev loop2, sector 264039 Buffer I/O error on dev loop2p3, logical block 263814, async page read Buffer I/O error on dev loop2p3, logical block 263815, async page read loop1: p2 < > p3 p4 loop4: p2 < > p3 p4 loop5: p2 < > p3 p4 audit: type=1804 audit(1650556305.623:8): pid=10390 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir555274195/syzkaller.UNmDDV/23/bus" dev="sda1" ino=13980 res=1 loop1: p3 size 1912633224 extends beyond EOD, truncated loop2: p2 < > p3 p4 loop1: p4 size 3657465856 extends beyond EOD, truncated loop5: p3 size 1912633224 extends beyond EOD, truncated loop4: p3 size 1912633224 extends beyond EOD, truncated kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns loop2: p3 size 1912633224 extends beyond EOD, truncated loop5: p4 size 3657465856 extends beyond EOD, truncated loop4: p4 size 3657465856 extends beyond EOD, truncated loop2: p4 size 3657465856 extends beyond EOD, truncated loop2: p2 < > p3 p4 loop2: p3 size 1912633224 extends beyond EOD, truncated loop2: p4 size 3657465856 extends beyond EOD, truncated kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns loop1: p2 < > p3 p4 loop1: p3 size 1912633224 extends beyond EOD, truncated kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns loop1: p4 size 3657465856 extends beyond EOD, truncated kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns audit: type=1804 audit(1650556306.543:9): pid=10489 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir555274195/syzkaller.UNmDDV/24/bus" dev="sda1" ino=13990 res=1 kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns audit: type=1804 audit(1650556306.964:10): pid=10529 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir1117612142/syzkaller.SUlUgP/29/bus" dev="sda1" ino=14000 res=1 kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns audit: type=1804 audit(1650556307.444:11): pid=10567 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir555274195/syzkaller.UNmDDV/25/bus" dev="sda1" ino=13963 res=1 audit: type=1804 audit(1650556307.814:12): pid=10589 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir1117612142/syzkaller.SUlUgP/30/bus" dev="sda1" ino=13977 res=1 audit: type=1804 audit(1650556308.154:13): pid=10598 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir2159481909/syzkaller.WC44sH/51/bus" dev="sda1" ino=14023 res=1 audit: type=1804 audit(1650556310.114:14): pid=10613 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir434458784/syzkaller.HmjyL7/34/bus" dev="sda1" ino=14028 res=1 audit: type=1804 audit(1650556310.114:15): pid=10611 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir555274195/syzkaller.UNmDDV/26/bus" dev="sda1" ino=14025 res=1