netlink: 68 bytes leftover after parsing attributes in process `syz-executor.4'. ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/602 is trying to acquire lock: 000000006fe2410c (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164 but task is already holding lock: 00000000ab06d9da (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] 00000000ab06d9da (sb_writers#3){.+.+}, at: do_sendfile+0x97d/0xc30 fs/read_write.c:1446 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (sb_writers#3){.+.+}: sb_start_write include/linux/fs.h:1579 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:360 ovl_create_object+0x96/0x290 fs/overlayfs/dir.c:602 lookup_open+0x893/0x1a20 fs/namei.c:3235 do_last fs/namei.c:3327 [inline] path_openat+0x1094/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&ovl_i_mutex_dir_key[depth]){++++}: inode_lock_shared include/linux/fs.h:758 [inline] do_last fs/namei.c:3326 [inline] path_openat+0x17ec/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_open_execat+0x11d/0x5b0 fs/exec.c:853 __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 __do_sys_execve fs/exec.c:1977 [inline] __se_sys_execve fs/exec.c:1972 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&sig->cred_guard_mutex){+.+.}: do_io_accounting fs/proc/base.c:2750 [inline] proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 __vfs_read+0xf7/0x750 fs/read_write.c:416 vfs_read+0x194/0x3c0 fs/read_write.c:452 ksys_read+0x12b/0x2a0 fs/read_write.c:579 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 seq_read+0x6b/0x11c0 fs/seq_file.c:164 proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x457/0xa00 fs/splice.c:417 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &p->lock --> &ovl_i_mutex_dir_key[depth] --> sb_writers#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]); lock(sb_writers#3); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz-executor.3/602: #0: 00000000ab06d9da (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] #0: 00000000ab06d9da (sb_writers#3){.+.+}, at: do_sendfile+0x97d/0xc30 fs/read_write.c:1446 stack backtrace: CPU: 0 PID: 602 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 seq_read+0x6b/0x11c0 fs/seq_file.c:164 proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x457/0xa00 fs/splice.c:417 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f9de6e39669 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9de57ad168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f9de6f5af80 RCX: 00007f9de6e39669 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00007f9de6e94560 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000010046 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcc995e34f R14: 00007f9de57ad300 R15: 0000000000022000 netlink: 68 bytes leftover after parsing attributes in process `syz-executor.5'. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 1054 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 __should_failslab+0x115/0x180 mm/failslab.c:32 should_failslab+0x5/0x10 mm/slab_common.c:1590 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x277/0x370 mm/slab.c:3557 kmem_cache_zalloc include/linux/slab.h:699 [inline] alloc_mm_slot mm/ksm.c:416 [inline] __ksm_enter+0x38/0x440 mm/ksm.c:2485 ksm_madvise+0x2e3/0x390 mm/ksm.c:2455 madvise_behavior mm/madvise.c:107 [inline] madvise_vma mm/madvise.c:700 [inline] __do_sys_madvise mm/madvise.c:873 [inline] __se_sys_madvise+0xaff/0x1c10 mm/madvise.c:801 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff9812b0669 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff97fc24168 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007ff9813d1f80 RCX: 00007ff9812b0669 RDX: 000000000000000c RSI: 0000000000002000 RDI: 0000000020ffe000 RBP: 00007ff97fc241d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc1ff5888f R14: 00007ff97fc24300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 1072 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 __should_failslab+0x115/0x180 mm/failslab.c:32 should_failslab+0x5/0x10 mm/slab_common.c:1590 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x277/0x370 mm/slab.c:3557 vm_area_dup+0x1c/0x170 kernel/fork.c:329 __split_vma+0xa5/0x560 mm/mmap.c:2624 madvise_behavior mm/madvise.c:154 [inline] madvise_vma mm/madvise.c:700 [inline] __do_sys_madvise mm/madvise.c:873 [inline] __se_sys_madvise+0xf0e/0x1c10 mm/madvise.c:801 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe netlink: 14 bytes leftover after parsing attributes in process `syz-executor.4'. RIP: 0033:0x7ff9812b0669 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff97fc24168 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007ff9813d1f80 RCX: 00007ff9812b0669 RDX: 000000000000000c RSI: 0000000000002000 RDI: 0000000020ffe000 RBP: 00007ff97fc241d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc1ff5888f R14: 00007ff97fc24300 R15: 0000000000022000 netlink: 14 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 14 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 14 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 14 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 14 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. IPVS: stopping backup sync thread 1225 ... IPVS: sync thread started: state = BACKUP, mcast_ifn = bridge0, syncid = 3, id = 0 netlink: 14 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.0'. IPVS: sync thread started: state = BACKUP, mcast_ifn = bridge0, syncid = 3, id = 0 IPVS: stopping backup sync thread 1291 ... netlink: 14 bytes leftover after parsing attributes in process `syz-executor.3'. IPVS: Unknown mcast interface: bridge0 IPVS: stopping backup sync thread 1321 ... IPVS: sync thread started: state = BACKUP, mcast_ifn = bridge0, syncid = 3, id = 0 IPVS: Unknown mcast interface: bridge0 IPVS: Unknown mcast interface: bridge0 nla_parse: 72 callbacks suppressed netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'.