Hello, syzbot found the following issue on: HEAD commit: 55027e689933 Merge tag 'input-for-v6.10-rc5' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16390ac1980000 kernel config: https://syzkaller.appspot.com/x/.config?x=53ab35b556129242 dashboard link: https://syzkaller.appspot.com/bug?extid=df3558df41609451e4ac compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-55027e68.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a36929b5a065/vmlinux-55027e68.xz kernel image: https://storage.googleapis.com/syzbot-assets/d72de6f61ddc/bzImage-55027e68.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+df3558df41609451e4ac@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc5-syzkaller-00018-g55027e689933 #0 Not tainted ------------------------------------------------------ syz-executor.2/6265 is trying to acquire lock: ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline] ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3891 [inline] ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3981 [inline] ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: __do_kmalloc_node mm/slub.c:4121 [inline] ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_noprof+0xb5/0x420 mm/slub.c:4135 but task is already holding lock: ffff88804af1a0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x33f/0xad0 fs/exfat/dir.c:256 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_lock#2){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 exfat_evict_inode+0x25b/0x340 fs/exfat/inode.c:725 evict+0x2ed/0x6c0 fs/inode.c:667 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 shrink_kill fs/dcache.c:1048 [inline] shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156 super_cache_scan+0x32a/0x550 fs/super.c:221 do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0xa87/0x1310 mm/shrinker.c:626 shrink_one+0x493/0x7c0 mm/vmscan.c:4790 shrink_many mm/vmscan.c:4851 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951 shrink_node mm/vmscan.c:5910 [inline] kswapd_shrink_node mm/vmscan.c:6720 [inline] balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] __do_kmalloc_node mm/slub.c:4121 [inline] __kmalloc_noprof+0xb5/0x420 mm/slub.c:4135 kmalloc_noprof include/linux/slab.h:664 [inline] kmalloc_array_noprof include/linux/slab.h:699 [inline] __exfat_get_dentry_set+0x81e/0xa90 fs/exfat/dir.c:816 exfat_get_dentry_set+0x36/0x210 fs/exfat/dir.c:859 exfat_get_uniname_from_ext_entry fs/exfat/dir.c:39 [inline] exfat_readdir+0x950/0x1520 fs/exfat/dir.c:155 exfat_iterate+0x3c7/0xad0 fs/exfat/dir.c:261 wrap_directory_iterator+0xa5/0xe0 fs/readdir.c:67 iterate_dir+0x53e/0xb60 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:409 [inline] __se_sys_getdents64 fs/readdir.c:394 [inline] __ia32_sys_getdents64+0x14f/0x2e0 fs/readdir.c:394 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_lock#2); lock(fs_reclaim); lock(&sbi->s_lock#2); lock(fs_reclaim); *** DEADLOCK *** 3 locks held by syz-executor.2/6265: #0: ffff88801db114c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xeb/0x180 fs/file.c:1191 #1: ffff8880483da9e8 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: wrap_directory_iterator+0x5a/0xe0 fs/readdir.c:56 #2: ffff88804af1a0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x33f/0xad0 fs/exfat/dir.c:256 stack backtrace: CPU: 0 PID: 6265 Comm: syz-executor.2 Not tainted 6.10.0-rc5-syzkaller-00018-g55027e689933 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] __do_kmalloc_node mm/slub.c:4121 [inline] __kmalloc_noprof+0xb5/0x420 mm/slub.c:4135 kmalloc_noprof include/linux/slab.h:664 [inline] kmalloc_array_noprof include/linux/slab.h:699 [inline] __exfat_get_dentry_set+0x81e/0xa90 fs/exfat/dir.c:816 exfat_get_dentry_set+0x36/0x210 fs/exfat/dir.c:859 exfat_get_uniname_from_ext_entry fs/exfat/dir.c:39 [inline] exfat_readdir+0x950/0x1520 fs/exfat/dir.c:155 exfat_iterate+0x3c7/0xad0 fs/exfat/dir.c:261 wrap_directory_iterator+0xa5/0xe0 fs/readdir.c:67 iterate_dir+0x53e/0xb60 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:409 [inline] __se_sys_getdents64 fs/readdir.c:394 [inline] __ia32_sys_getdents64+0x14f/0x2e0 fs/readdir.c:394 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf72f8579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5ec95ac EFLAGS: 00000292 ORIG_RAX: 00000000000000dc RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000020002ec0 RDX: 0000000000001000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
