Message-ID: <6782483e.050a0220.216c54.001d.GAE@google.com>
Date: Sat, 11 Jan 2025 02:30:22 -0800
From: syzbot <syzbot+799a2d4576c454ac2693@...kaller.appspotmail.com>
To: arve@...roid.com, brauner@...nel.org, cmllamas@...gle.com, 
	gregkh@...uxfoundation.org, joel@...lfernandes.org, 
	linux-kernel@...r.kernel.org, maco@...roid.com, surenb@...gle.com, 
	syzkaller-bugs@...glegroups.com, tkjos@...roid.com
Subject: [syzbot] [kernel?] possible deadlock in binder_alloc_free_page

Hello,

syzbot found the following issue on:

HEAD commit:    7b4b9bf203da Add linux-next specific files for 20250107
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17d02dc4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=63fa2c9d5e12faef
dashboard link: https://syzkaller.appspot.com/bug?extid=799a2d4576c454ac2693
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10302dc4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c179cc0c7a3c/disk-7b4b9bf2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fdea80f2ec16/vmlinux-7b4b9bf2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a277fcaff608/bzImage-7b4b9bf2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+799a2d4576c454ac2693@...kaller.appspotmail.com

binder: 7926:7927 ioctl 4018620d 0 returned -22
======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc6-next-20250107-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.906/7927 is trying to acquire lock:
ffff88803376f5c8 (vm_lock){++++}-{0:0}, at: binder_alloc_free_page+0x150/0xd50 drivers/android/binder_alloc.c:1156

but task is already holding lock:
ffff888030320e30 (&l->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff888030320e30 (&l->lock){+.+.}-{3:3}, at: lock_list_lru_of_memcg+0x24c/0x4d0 mm/list_lru.c:77

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&l->lock){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       lock_list_lru_of_memcg+0x24c/0x4d0 mm/list_lru.c:77
       list_lru_add+0x59/0x270 mm/list_lru.c:163
       list_lru_add_obj+0x17b/0x250 mm/list_lru.c:186
       __inode_add_lru fs/inode.c:534 [inline]
       iput_final fs/inode.c:1923 [inline]
       iput+0x89c/0xa50 fs/inode.c:1972
       __dentry_kill+0x20d/0x630 fs/dcache.c:625
       shrink_kill+0xa9/0x2c0 fs/dcache.c:1070
       shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1097
       shrink_dcache_sb+0x25e/0x3e0 fs/dcache.c:1217
       reconfigure_super+0x2c6/0x870 fs/super.c:1061
       do_remount fs/namespace.c:3100 [inline]
       path_mount+0xc22/0xfa0 fs/namespace.c:3879
       do_mount fs/namespace.c:3900 [inline]
       __do_sys_mount fs/namespace.c:4111 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&sb->s_type->i_lock_key#23){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       __mark_inode_dirty+0x3ff/0xe90 fs/fs-writeback.c:2540
       generic_update_time fs/inode.c:2112 [inline]
       inode_update_time fs/inode.c:2125 [inline]
       __file_update_time fs/inode.c:2353 [inline]
       file_update_time+0x3d2/0x450 fs/inode.c:2383
       ext4_page_mkwrite+0x210/0x1100 fs/ext4/inode.c:6160
       do_page_mkwrite+0x159/0x340 mm/memory.c:3244
       wp_page_shared mm/memory.c:3645 [inline]
       do_wp_page+0x23cd/0x49b0 mm/memory.c:3795
       handle_pte_fault mm/memory.c:5905 [inline]
       __handle_mm_fault+0x24cf/0x70f0 mm/memory.c:6032
       handle_mm_fault+0x3e2/0x8c0 mm/memory.c:6201
       do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
       handle_page_fault arch/x86/mm/fault.c:1480 [inline]
       exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1538
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #1 (sb_pagefaults){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       percpu_down_read+0x44/0x1b0 include/linux/percpu-rwsem.h:51
       __sb_start_write include/linux/fs.h:1773 [inline]
       sb_start_pagefault include/linux/fs.h:1938 [inline]
       ext4_page_mkwrite+0x1f9/0x1100 fs/ext4/inode.c:6159
       do_page_mkwrite+0x159/0x340 mm/memory.c:3244
       do_shared_fault mm/memory.c:5468 [inline]
       do_fault mm/memory.c:5530 [inline]
       do_pte_missing mm/memory.c:4047 [inline]
       handle_pte_fault mm/memory.c:5889 [inline]
       __handle_mm_fault+0x22dc/0x70f0 mm/memory.c:6032
       handle_mm_fault+0x3e2/0x8c0 mm/memory.c:6201
       do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
       handle_page_fault arch/x86/mm/fault.c:1480 [inline]
       exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1538
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #0 (vm_lock){++++}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       vma_start_read include/linux/mm.h:749 [inline]
       lock_vma_under_rcu+0x35f/0x9a0 mm/memory.c:6436
       binder_alloc_free_page+0x150/0xd50 drivers/android/binder_alloc.c:1156
       __list_lru_walk_one+0x170/0x470 mm/list_lru.c:300
       list_lru_walk_one mm/list_lru.c:337 [inline]
       list_lru_walk_node+0xc4/0xa70 mm/list_lru.c:357
       list_lru_walk include/linux/list_lru.h:282 [inline]
       binder_shrink_scan+0x138/0x260 drivers/android/binder_alloc.c:1226
       do_shrink_slab+0x72d/0x1160 mm/shrinker.c:437
       shrink_slab+0x1093/0x14d0 mm/shrinker.c:664
       drop_slab_node mm/vmscan.c:421 [inline]
       drop_slab+0x142/0x280 mm/vmscan.c:439
       drop_caches_sysctl_handler+0xbc/0x160 fs/drop_caches.c:68
       proc_sys_call_handler+0x5ec/0x920 fs/proc/proc_sysctl.c:601
       do_iter_readv_writev+0x71a/0x9d0
       vfs_writev+0x38b/0xbc0 fs/read_write.c:1050
       do_writev+0x1b6/0x360 fs/read_write.c:1096
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  vm_lock --> &sb->s_type->i_lock_key#23 --> &l->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&l->lock);
                               lock(&sb->s_type->i_lock_key#23);
                               lock(&l->lock);
  rlock(vm_lock);

 *** DEADLOCK ***

4 locks held by syz.2.906/7927:
 #0: ffff888032732d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192
 #1: ffff888027bea420 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3016 [inline]
 #1: ffff888027bea420 (sb_writers#3){.+.+}-{0:0}, at: vfs_writev+0x2d6/0xbc0 fs/read_write.c:1048
 #2: ffff888030320e30 (&l->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffff888030320e30 (&l->lock){+.+.}-{3:3}, at: lock_list_lru_of_memcg+0x24c/0x4d0 mm/list_lru.c:77
 #3: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #3: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: lock_vma_under_rcu+0x1dd/0x9a0 mm/memory.c:6431

stack backtrace:
CPU: 1 UID: 0 PID: 7927 Comm: syz.2.906 Not tainted 6.13.0-rc6-next-20250107-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 vma_start_read include/linux/mm.h:749 [inline]
 lock_vma_under_rcu+0x35f/0x9a0 mm/memory.c:6436
 binder_alloc_free_page+0x150/0xd50 drivers/android/binder_alloc.c:1156
 __list_lru_walk_one+0x170/0x470 mm/list_lru.c:300
 list_lru_walk_one mm/list_lru.c:337 [inline]
 list_lru_walk_node+0xc4/0xa70 mm/list_lru.c:357
 list_lru_walk include/linux/list_lru.h:282 [inline]
 binder_shrink_scan+0x138/0x260 drivers/android/binder_alloc.c:1226
 do_shrink_slab+0x72d/0x1160 mm/shrinker.c:437
 shrink_slab+0x1093/0x14d0 mm/shrinker.c:664
 drop_slab_node mm/vmscan.c:421 [inline]
 drop_slab+0x142/0x280 mm/vmscan.c:439
 drop_caches_sysctl_handler+0xbc/0x160 fs/drop_caches.c:68
 proc_sys_call_handler+0x5ec/0x920 fs/proc/proc_sysctl.c:601
 do_iter_readv_writev+0x71a/0x9d0
 vfs_writev+0x38b/0xbc0 fs/read_write.c:1050
 do_writev+0x1b6/0x360 fs/read_write.c:1096
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc9ae785d29
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:00007fc9af619038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fc9ae975fa0 RCX: 00007fc9ae785d29
RDX: 0000000000000001 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007fc9ae801b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc9ae975fa0 R15: 00007ffd15c33b58
 </TASK>
syz.2.906 (7927): drop_caches: 2


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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If the report is already addressed, let syzbot know by replying with:
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If you want to overwrite report's subsystems, reply with:
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