====================================================== WARNING: possible circular locking dependency detected 4.14.276-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/9796 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.5/9796: #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: 9796 Comm: syz-executor.5 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: 0033:0x7fb2d99690e9 RSP: 002b:00007fb2d82de168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb2d9a7bf60 RCX: 00007fb2d99690e9 RDX: 0000000000000000 RSI: 000000000000770a RDI: 0000000000000005 RBP: 00007fb2d99c308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc4d99fbf R14: 00007fb2d82de300 R15: 0000000000022000 overlayfs: fs on './file0' does not support file handles, falling back to index=off. audit: type=1804 audit(1650656475.791:17): pid=9940 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir1947854307/syzkaller.uMwUB8/21/bus" dev="sda1" ino=13930 res=1 overlayfs: fs on './file0' does not support file handles, falling back to index=off. audit: type=1800 audit(1650656475.791:18): pid=9940 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=13930 res=0 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. XFS (loop4): Invalid superblock magic number ISO 9660 Extensions: Microsoft Joliet Level 0 init_special_inode: bogus i_mode (0) for inode loop2:1792 overlayfs: fs on './file0' does not support file handles, falling back to index=off. overlayfs: fs on './file0' does not support file handles, falling back to index=off. isofs_fill_super: root inode is not a directory. Corrupted media? audit: type=1804 audit(1650656477.291:19): pid=10023 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir1947854307/syzkaller.uMwUB8/22/bus" dev="sda1" ino=13956 res=1 audit: type=1800 audit(1650656477.291:20): pid=10023 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=13956 res=0 audit: type=1804 audit(1650656477.331:21): pid=10025 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir526969176/syzkaller.9Qf6De/17/bus" dev="sda1" ino=13957 res=1 audit: type=1800 audit(1650656477.331:22): pid=10025 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="bus" dev="sda1" ino=13957 res=0 audit: type=1804 audit(1650656477.791:23): pid=10044 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir1947854307/syzkaller.uMwUB8/23/bus" dev="sda1" ino=13909 res=1 audit: type=1800 audit(1650656477.791:24): pid=10044 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="bus" dev="sda1" ino=13909 res=0 XFS (loop4): Invalid superblock magic number ISO 9660 Extensions: Microsoft Joliet Level 0 init_special_inode: bogus i_mode (0) for inode loop2:1792 isofs_fill_super: root inode is not a directory. Corrupted media? kauditd_printk_skb: 4 callbacks suppressed audit: type=1804 audit(1650656479.321:29): pid=10098 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir526969176/syzkaller.9Qf6De/19/bus" dev="sda1" ino=13966 res=1 netlink: 176 bytes leftover after parsing attributes in process `syz-executor.1'. ISO 9660 Extensions: Microsoft Joliet Level 0 init_special_inode: bogus i_mode (0) for inode loop2:1792 isofs_fill_super: root inode is not a directory. Corrupted media? audit: type=1800 audit(1650656479.321:30): pid=10098 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="bus" dev="sda1" ino=13966 res=0 netlink: 176 bytes leftover after parsing attributes in process `syz-executor.1'. ISO 9660 Extensions: Microsoft Joliet Level 0 init_special_inode: bogus i_mode (0) for inode loop2:1792 isofs_fill_super: root inode is not a directory. Corrupted media? netlink: 176 bytes leftover after parsing attributes in process `syz-executor.1'. XFS (loop4): Invalid superblock magic number netlink: 176 bytes leftover after parsing attributes in process `syz-executor.1'. team0: Cannot enslave team device to itself batman_adv: batadv0: Adding interface: team0 batman_adv: batadv0: The MTU of interface team0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface team0 (retrying later): interface not active XFS (loop4): Invalid superblock magic number batman_adv: batadv0: Removing interface: team0 team0: Cannot enslave team device to itself team0: Port device ipvlan1 added batman_adv: batadv0: Adding interface: team0 batman_adv: batadv0: The MTU of interface team0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface team0 (retrying later): interface not active batman_adv: batadv0: Removing interface: team0 team0: Cannot enslave team device to itself batman_adv: batadv0: Adding interface: team0 batman_adv: batadv0: The MTU of interface team0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface team0 (retrying later): interface not active batman_adv: batadv0: Removing interface: team0 team0: Cannot enslave team device to itself batman_adv: batadv0: Adding interface: team0 batman_adv: batadv0: The MTU of interface team0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface team0 (retrying later): interface not active usb usb2: usbfs: process 10292 (syz-executor.3) did not claim interface 0 before use usb usb2: usbfs: process 10326 (syz-executor.3) did not claim interface 0 before use usb usb2: usbfs: process 10477 (syz-executor.3) did not claim interface 0 before use usb usb2: usbfs: process 10569 (syz-executor.3) did not claim interface 0 before use VFS: Lookup of 'file0' in fuse fuse would have caused loop overlayfs: workdir and upperdir must be separate subtrees sd 0:0:1:0: [sg0] tag#2684 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK sd 0:0:1:0: [sg0] tag#2684 CDB: opcode=0xe5 (vendor) sd 0:0:1:0: [sg0] tag#2684 CDB[00]: e5 f4 32 73 2f 4e 09 6d 26 e2 c7 35 d1 35 12 1c sd 0:0:1:0: [sg0] tag#2684 CDB[10]: 92 1b da 40 b8 58 5b a8 d4 7d 34 f3 90 4c f1 2d sd 0:0:1:0: [sg0] tag#2684 CDB[20]: ba device lo entered promiscuous mode Y4`Ҙ: renamed from lo sd 0:0:1:0: [sg0] tag#2684 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK sd 0:0:1:0: [sg0] tag#2684 CDB: opcode=0xe5 (vendor) sd 0:0:1:0: [sg0] tag#2684 CDB[00]: e5 f4 32 73 2f 4e 09 6d 26 e2 c7 35 d1 35 12 1c sd 0:0:1:0: [sg0] tag#2684 CDB[10]: 92 1b da 40 b8 58 5b a8 d4 7d 34 f3 90 4c f1 2d sd 0:0:1:0: [sg0] tag#2684 CDB[20]: ba sd 0:0:1:0: [sg0] tag#2688 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK sd 0:0:1:0: [sg0] tag#2688 CDB: opcode=0xe5 (vendor) sd 0:0:1:0: [sg0] tag#2688 CDB[00]: e5 f4 32 73 2f 4e 09 6d 26 e2 c7 35 d1 35 12 1c sd 0:0:1:0: [sg0] tag#2688 CDB[10]: 92 1b da 40 b8 58 5b a8 d4 7d 34 f3 90 4c f1 2d sd 0:0:1:0: [sg0] tag#2688 CDB[20]: ba device lo entered promiscuous mode Y4`Ҙ: renamed from lo