======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc5-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.1318/10014 is trying to acquire lock:
ffff88802b6b2798 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable include/linux/mmap_lock.h:153 [inline]
ffff88802b6b2798 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5878 [inline]
ffff88802b6b2798 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x3a9/0x6a0 mm/memory.c:5929
but task is already holding lock:
ffff8880302e8b70 (&ctx->wb_lock){+.+.}-{3:3}, at: netfs_begin_writethrough+0x6c/0x3c0 fs/netfs/write_issue.c:572
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&ctx->wb_lock){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
netfs_writepages+0x5e1/0xdd0 fs/netfs/write_issue.c:509
do_writepages+0x1a3/0x7f0 mm/page-writeback.c:2683
filemap_fdatawrite_wbc mm/filemap.c:397 [inline]
filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:387
v9fs_mmap_vm_close+0x213/0x260 fs/9p/vfs_file.c:502
remove_vma+0x8b/0x180 mm/mmap.c:182
remove_mt mm/mmap.c:2415 [inline]
do_vmi_align_munmap+0x1272/0x19c0 mm/mmap.c:2758
do_vmi_munmap+0x231/0x410 mm/mmap.c:2830
mmap_region+0x17f/0x2760 mm/mmap.c:2881
do_mmap+0xbfb/0xfb0 mm/mmap.c:1468
vm_mmap_pgoff+0x1ba/0x360 mm/util.c:588
ksys_mmap_pgoff+0x332/0x5d0 mm/mmap.c:1514
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:79 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:79
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&mm->mmap_lock){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain kernel/locking/lockdep.c:3868 [inline]
__lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142
lock_acquire kernel/locking/lockdep.c:5759 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
down_read_killable+0x9d/0x380 kernel/locking/rwsem.c:1549
mmap_read_lock_killable include/linux/mmap_lock.h:153 [inline]
get_mmap_lock_carefully mm/memory.c:5878 [inline]
lock_mm_and_find_vma+0x3a9/0x6a0 mm/memory.c:5929
do_user_addr_fault+0x2b5/0x13f0 arch/x86/mm/fault.c:1361
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
fault_in_readable+0x126/0x230 mm/gup.c:2244
fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:94
netfs_perform_write+0x3ef/0x2250 fs/netfs/buffered_write.c:240
netfs_buffered_write_iter_locked+0x213/0x2c0 fs/netfs/buffered_write.c:470
netfs_file_write_iter+0x1e0/0x470 fs/netfs/buffered_write.c:509
v9fs_file_write_iter+0xa1/0x100 fs/9p/vfs_file.c:407
aio_write+0x3c1/0x8e0 fs/aio.c:1633
__io_submit_one fs/aio.c:2005 [inline]
io_submit_one+0x124e/0x1db0 fs/aio.c:2052
__do_sys_io_submit fs/aio.c:2111 [inline]
__se_sys_io_submit fs/aio.c:2081 [inline]
__x64_sys_io_submit+0x19d/0x330 fs/aio.c:2081
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ctx->wb_lock);
lock(&mm->mmap_lock);
lock(&ctx->wb_lock);
rlock(&mm->mmap_lock);
*** DEADLOCK ***
2 locks held by syz.2.1318/10014:
#0: ffff8880302e87b8 (&sb->s_type->i_mutex_key#25){++++}-{3:3}, at: netfs_start_io_write+0x1f/0x70 fs/netfs/locking.c:118
#1: ffff8880302e8b70 (&ctx->wb_lock){+.+.}-{3:3}, at: netfs_begin_writethrough+0x6c/0x3c0 fs/netfs/write_issue.c:572
stack backtrace:
CPU: 1 UID: 0 PID: 10014 Comm: syz.2.1318 Not tainted 6.11.0-rc5-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain kernel/locking/lockdep.c:3868 [inline]
__lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142
lock_acquire kernel/locking/lockdep.c:5759 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
down_read_killable+0x9d/0x380 kernel/locking/rwsem.c:1549
mmap_read_lock_killable include/linux/mmap_lock.h:153 [inline]
get_mmap_lock_carefully mm/memory.c:5878 [inline]
lock_mm_and_find_vma+0x3a9/0x6a0 mm/memory.c:5929
do_user_addr_fault+0x2b5/0x13f0 arch/x86/mm/fault.c:1361
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:fault_in_readable+0x126/0x230 mm/gup.c:2244
Code: f7 bc ff 48 39 dd 0f 84 f0 00 00 00 45 31 f6 eb 11 e8 6e f7 bc ff 48 81 c3 00 10 00 00 48 39 eb 74 1d e8 5d f7 bc ff 45 89 f7 <8a> 03 31 ff 44 89 fe 88 44 24 28 e8 8a f9 bc ff 45 85 ff 74 d2 e8
RSP: 0018:ffffc900032d7650 EFLAGS: 00050287
RAX: 0000000000030b60 RBX: 0000000020005000 RCX: ffffc900040f9000
RDX: 0000000000040000 RSI: ffffffff81cd8213 RDI: 0000000000000005
RBP: 0000000020006000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000001000
R13: 0000000020004180 R14: 0000000000000000 R15: 0000000000000000
fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:94
netfs_perform_write+0x3ef/0x2250 fs/netfs/buffered_write.c:240
netfs_buffered_write_iter_locked+0x213/0x2c0 fs/netfs/buffered_write.c:470
netfs_file_write_iter+0x1e0/0x470 fs/netfs/buffered_write.c:509
v9fs_file_write_iter+0xa1/0x100 fs/9p/vfs_file.c:407
aio_write+0x3c1/0x8e0 fs/aio.c:1633
__io_submit_one fs/aio.c:2005 [inline]
io_submit_one+0x124e/0x1db0 fs/aio.c:2052
__do_sys_io_submit fs/aio.c:2111 [inline]
__se_sys_io_submit fs/aio.c:2081 [inline]
__x64_sys_io_submit+0x19d/0x330 fs/aio.c:2081
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f86fd779e79
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f86fe526038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007f86fd915f80 RCX: 00007f86fd779e79
RDX: 0000000020000700 RSI: 000000000000140b RDI: 00007f86fe4fe000
RBP: 00007f86fd7e793e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f86fd915f80 R15: 00007ffe70f66888
</TASK>
input: syz0 as /devices/virtual/input/input13
netlink: 'syz.2.1318': attribute type 2 has an invalid length.
netlink: 'syz.2.1318': attribute type 1 has an invalid length.
----------------
Code disassembly (best guess), 1 bytes skipped:
0: bc ff 48 39 dd mov $0xdd3948ff,%esp
5: 0f 84 f0 00 00 00 je 0xfb
b: 45 31 f6 xor %r14d,%r14d
e: eb 11 jmp 0x21
10: e8 6e f7 bc ff call 0xffbcf783
15: 48 81 c3 00 10 00 00 add $0x1000,%rbx
1c: 48 39 eb cmp %rbp,%rbx
1f: 74 1d je 0x3e
21: e8 5d f7 bc ff call 0xffbcf783
26: 45 89 f7 mov %r14d,%r15d
* 29: 8a 03 mov (%rbx),%al <-- trapping instruction
2b: 31 ff xor %edi,%edi
2d: 44 89 fe mov %r15d,%esi
30: 88 44 24 28 mov %al,0x28(%rsp)
34: e8 8a f9 bc ff call 0xffbcf9c3
39: 45 85 ff test %r15d,%r15d
3c: 74 d2 je 0x10
3e: e8 .byte 0xe8