====================================================== [ INFO: possible circular locking dependency detected ] 4.9.202+ #0 Not tainted ------------------------------------------------------- syz-executor.0/5897 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<000000007cc609f0>] __do_page_fault+0x7bd/0xa60 arch/x86/mm/fault.c:1337 but task is already holding lock: (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000005d7e3c5>] inode_lock include/linux/fs.h:771 [inline] (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000005d7e3c5>] generic_file_write_iter+0x9a/0x630 mm/filemap.c:3090 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759 down_write+0x41/0xa0 kernel/locking/rwsem.c:52 inode_lock include/linux/fs.h:771 [inline] shmem_fallocate+0x143/0xab0 mm/shmem.c:2683 ashmem_shrink_scan drivers/staging/android/ashmem.c:462 [inline] ashmem_shrink_scan+0x1c3/0x4c0 drivers/staging/android/ashmem.c:446 ashmem_ioctl+0x29b/0xdd0 drivers/staging/android/ashmem.c:804 vfs_ioctl fs/ioctl.c:43 [inline] file_ioctl fs/ioctl.c:493 [inline] do_vfs_ioctl+0xb87/0x11d0 fs/ioctl.c:677 SYSC_ioctl fs/ioctl.c:694 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 entry_SYSCALL_64_after_swapgs+0x5d/0xdb lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759 __mutex_lock_common kernel/locking/mutex.c:521 [inline] mutex_lock_nested+0xc7/0x920 kernel/locking/mutex.c:621 ashmem_mmap+0x53/0x470 drivers/staging/android/ashmem.c:378 mmap_region+0x7e7/0xfa0 mm/mmap.c:1726 do_mmap+0x539/0xbc0 mm/mmap.c:1505 do_mmap_pgoff include/linux/mm.h:2066 [inline] vm_mmap_pgoff+0x179/0x1c0 mm/util.c:329 SYSC_mmap_pgoff mm/mmap.c:1555 [inline] SyS_mmap_pgoff+0xfa/0x1b0 mm/mmap.c:1513 SYSC_mmap arch/x86/kernel/sys_x86_64.c:96 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:87 do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 entry_SYSCALL_64_after_swapgs+0x5d/0xdb check_prev_add kernel/locking/lockdep.c:1828 [inline] check_prevs_add kernel/locking/lockdep.c:1938 [inline] validate_chain kernel/locking/lockdep.c:2265 [inline] __lock_acquire+0x2d22/0x4390 kernel/locking/lockdep.c:3345 lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759 down_read+0x44/0xb0 kernel/locking/rwsem.c:22 __do_page_fault+0x7bd/0xa60 arch/x86/mm/fault.c:1337 do_page_fault+0x28/0x30 arch/x86/mm/fault.c:1464 page_fault+0x25/0x30 arch/x86/entry/entry_64.S:956 generic_perform_write+0x1b6/0x500 mm/filemap.c:2930 __generic_file_write_iter+0x340/0x530 mm/filemap.c:3065 generic_file_write_iter+0x38a/0x630 mm/filemap.c:3093 new_sync_write fs/read_write.c:498 [inline] __vfs_write+0x3c1/0x560 fs/read_write.c:511 vfs_write+0x185/0x520 fs/read_write.c:559 SYSC_pwrite64 fs/read_write.c:649 [inline] SyS_pwrite64+0x13f/0x170 fs/read_write.c:636 do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 entry_SYSCALL_64_after_swapgs+0x5d/0xdb other info that might help us debug this: Chain exists of: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#10); lock(ashmem_mutex); lock(&sb->s_type->i_mutex_key#10); lock(&mm->mmap_sem); *** DEADLOCK *** 2 locks held by syz-executor.0/5897: #0: (sb_writers#6){.+.+.+}, at: [<0000000059fc635e>] file_start_write include/linux/fs.h:2645 [inline] #0: (sb_writers#6){.+.+.+}, at: [<0000000059fc635e>] vfs_write+0x3e9/0x520 fs/read_write.c:558 #1: (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000005d7e3c5>] inode_lock include/linux/fs.h:771 [inline] #1: (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000005d7e3c5>] generic_file_write_iter+0x9a/0x630 mm/filemap.c:3090 stack backtrace: CPU: 1 PID: 5897 Comm: syz-executor.0 Not tainted 4.9.202+ #0 ffff8801a17775e8 ffffffff81b55d2b ffffffff83cae9d0 ffffffff83cb8000 ffffffff83ceef30 ffffffff8424ff40 ffff8801a16417c0 ffff8801a1777640 ffffffff81406d6a ffffffff8120d1c5 ffffffff84060a40 ffff8801a16420c0 Call Trace: [<000000007da3d68c>] __dump_stack lib/dump_stack.c:15 [inline] [<000000007da3d68c>] dump_stack+0xcb/0x130 lib/dump_stack.c:56 [<00000000ee479657>] print_circular_bug.cold+0x2f6/0x454 kernel/locking/lockdep.c:1202 [<000000007f6d2d75>] check_prev_add kernel/locking/lockdep.c:1828 [inline] [<000000007f6d2d75>] check_prevs_add kernel/locking/lockdep.c:1938 [inline] [<000000007f6d2d75>] validate_chain kernel/locking/lockdep.c:2265 [inline] [<000000007f6d2d75>] __lock_acquire+0x2d22/0x4390 kernel/locking/lockdep.c:3345 [<0000000054cb74c6>] lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759 [<00000000351b9d2d>] down_read+0x44/0xb0 kernel/locking/rwsem.c:22 [<000000007cc609f0>] __do_page_fault+0x7bd/0xa60 arch/x86/mm/fault.c:1337 [<000000007923fdd1>] do_page_fault+0x28/0x30 arch/x86/mm/fault.c:1464 [<00000000b283b671>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:956 [<00000000322abe9e>] generic_perform_write+0x1b6/0x500 mm/filemap.c:2930 [<0000000026bdf6f2>] __generic_file_write_iter+0x340/0x530 mm/filemap.c:3065 [<000000004649e8ce>] generic_file_write_iter+0x38a/0x630 mm/filemap.c:3093 [<000000005885e685>] new_sync_write fs/read_write.c:498 [inline] [<000000005885e685>] __vfs_write+0x3c1/0x560 fs/read_write.c:511 [<00000000d0c05149>] vfs_write+0x185/0x520 fs/read_write.c:559 [<000000002f2c9210>] SYSC_pwrite64 fs/read_write.c:649 [inline] [<000000002f2c9210>] SyS_pwrite64+0x13f/0x170 fs/read_write.c:636 [<000000002dedab42>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<00000000f90e6c59>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb EXT4-fs (loop2): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock selinux_nlmsg_perm: 865 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=115 sclass=netlink_route_socket pig=6177 comm=syz-executor.5 EXT4-fs (loop2): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop2): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs error (device loop2): ext4_iget:4556: inode #2: comm syz-executor.2: root inode unallocated EXT4-fs (loop2): get root inode failed EXT4-fs (loop2): mount failed audit_printk_skb: 15 callbacks suppressed audit: type=1400 audit(1574652771.119:42): avc: denied { create } for pid=6196 comm="syz-executor.2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 audit: type=1400 audit(1574652771.179:43): avc: denied { write } for pid=6196 comm="syz-executor.2" path="socket:[14424]" dev="sockfs" ino=14424 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 netlink: 16 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 16 bytes leftover after parsing attributes in process `syz-executor.5'. audit: type=1400 audit(1574652774.469:44): avc: denied { map_create } for pid=6692 comm="syz-executor.0" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 blk_update_request: I/O error, dev loop0, sector 0 F2FS-fs (loop0): Unable to read 1th superblock blk_update_request: I/O error, dev loop0, sector 8 F2FS-fs (loop0): Unable to read 2th superblock audit: type=1400 audit(1574652774.599:45): avc: denied { associate } for pid=6706 comm="syz-executor.0" name="/" dev="sysfs" ino=1 scontext=system_u:object_r:locale_t:s0 tcontext=system_u:object_r:sysfs_t:s0 tclass=filesystem permissive=1 binder: 6705:6709 unknown command 1661665294 binder: 6705:6709 ioctl c0306201 20000080 returned -22 EXT4-fs (loop1): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock EXT4-fs (loop1): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop1): ext4_check_descriptors: Inode table for group 0 overlaps superblock [EXT4 FS bs=2048, gc=1, bpg=16384, ipg=128, mo=e002401c, mo2=0002] System zones: 0-7 EXT4-fs (loop1): mounting with "discard" option, but the device does not support discard EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue binder: 6705:6719 unknown command 1661665294 binder: 6705:6719 ioctl c0306201 20000080 returned -22 device ip_vti0 entered promiscuous mode device ip6_vti0 entered promiscuous mode device sit0 entered promiscuous mode device ip6tnl0 entered promiscuous mode device syz_tun entered promiscuous mode device ip6_vti1 entered promiscuous mode