EXT4-fs (loop7): unable to read superblock ===================================== WARNING: bad unlock balance detected! 6.19.0-rc5-next-20260116 #1 Not tainted ------------------------------------- syz-executor.6/4441 is trying to release lock (rcu_read_lock) at: [] __wait_on_freeing_inode+0x105/0x350 but there are no more locks to release! other info that might help us debug this: 4 locks held by syz-executor.6/4441: #0: ffff88800fa7a3f8 (sb_writers#3){.+.+}-{0:0}, at: filename_create+0xf7/0x400 #1: ffff88801b1a6cb8 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1b1/0x400 #2: ffff88800fa7e950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xe32/0x12d0 #3: ffffffff85c16898 (inode_hash_lock){+.+.}-{3:3}, at: insert_inode_locked+0xf9/0x890 stack backtrace: CPU: 0 UID: 0 PID: 4441 Comm: syz-executor.6 Not tainted 6.19.0-rc5-next-20260116 #1 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xca/0x120 print_unlock_imbalance_bug+0x118/0x130 lock_release+0x1ee/0x270 __wait_on_freeing_inode+0x10a/0x350 insert_inode_locked+0x25f/0x890 __ext4_new_inode+0x223d/0x4cd0 ext4_symlink+0x623/0xb40 vfs_symlink+0x44b/0x840 filename_symlinkat+0x158/0x440 __x64_sys_symlink+0x82/0x110 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f550d08a427 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd7c522cc8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f550d08a427 RDX: ffffffffffffffbc RSI: 00007f550d0e500e RDI: 00007f550d0e41dd RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffd7c522740 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffd7c522d90 ------------[ cut here ]------------ WARNING: kernel/rcu/tree_plugin.h:443 at __rcu_read_unlock+0x25f/0x5c0, CPU#0: syz-executor.6/4441 Modules linked in: CPU: 0 UID: 0 PID: 4441 Comm: syz-executor.6 Not tainted 6.19.0-rc5-next-20260116 #1 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:__rcu_read_unlock+0x25f/0x5c0 Code: f2 02 00 00 c7 43 58 01 00 00 00 bf 09 00 00 00 e8 d6 b7 de ff 4d 85 f6 0f 84 73 fe ff ff e8 38 8a 20 00 fb e9 68 fe ff ff 90 <0f> 0b 90 5b 5d 41 5c 41 5d 41 5e e9 81 4d 74 03 e8 2c 5d 56 00 e9 RSP: 0018:ffff888048d279a0 EFLAGS: 00010286 RAX: 00000000ffffffff RBX: ffff888019888000 RCX: ffffffff815660f7 RDX: 0000000000000000 RSI: ffffffff81566100 RDI: ffff8880198883fc RBP: ffff888019888000 R08: 0000000000000000 R09: fffffbfff0ba7040 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888019888000 R13: 0000000000000001 R14: ffffffff85c0d150 R15: ffff88801b1ba938 FS: 000055557fc82400(0000) GS:ffff8880e5342000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f28f5d73544 CR3: 000000004dc52000 CR4: 0000000000350ef0 Call Trace: __wait_on_freeing_inode+0x10f/0x350 insert_inode_locked+0x25f/0x890 __ext4_new_inode+0x223d/0x4cd0 ext4_symlink+0x623/0xb40 vfs_symlink+0x44b/0x840 filename_symlinkat+0x158/0x440 __x64_sys_symlink+0x82/0x110 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f550d08a427 Code: 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd7c522cc8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f550d08a427 RDX: ffffffffffffffbc RSI: 00007f550d0e500e RDI: 00007f550d0e41dd RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffd7c522740 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffd7c522d90 irq event stamp: 637 hardirqs last enabled at (637): [] _raw_spin_unlock_irqrestore+0x2c/0x50 hardirqs last disabled at (636): [] _raw_spin_lock_irqsave+0x53/0x60 softirqs last enabled at (632): [] kernel_fpu_end+0x59/0x70 softirqs last disabled at (630): [] kernel_fpu_begin_mask+0x1bb/0x300 ---[ end trace 0000000000000000 ]--- loop7: detected capacity change from 0 to 4 EXT4-fs (loop7): VFS: Can't find ext4 filesystem FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 1 CPU: 0 UID: 0 PID: 4452 Comm: syz-executor.5 Tainted: G W 6.19.0-rc5-next-20260116 #1 PREEMPT(lazy) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xfa/0x120 should_fail_ex+0x4d7/0x5e0 _copy_from_user+0x30/0xd0 __x64_sys_sigaltstack+0xeb/0x380 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff5ca846b19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff5c7dbc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000083 RAX: ffffffffffffffda RBX: 00007ff5ca959f60 RCX: 00007ff5ca846b19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020ffc000 RBP: 00007ff5c7dbc1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe0cc447df R14: 00007ff5c7dbc300 R15: 0000000000022000 loop7: detected capacity change from 0 to 4 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 1 CPU: 0 UID: 0 PID: 4466 Comm: syz-executor.5 Tainted: G W 6.19.0-rc5-next-20260116 #1 PREEMPT(lazy) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xfa/0x120 should_fail_ex+0x4d7/0x5e0 should_fail_alloc_page+0xe0/0x110 prepare_alloc_pages+0x1eb/0x550 __alloc_frozen_pages_noprof+0x186/0x25b0 alloc_pages_mpol+0xed/0x340 alloc_pages_noprof+0xa1/0x380 pte_alloc_one+0x1e/0x3f0 __pte_alloc+0x6c/0x3f0 __handle_mm_fault+0x246e/0x2fa0 handle_mm_fault+0x2d8/0x750 do_user_addr_fault+0x3cc/0x12b0 exc_page_fault+0xb0/0x180 asm_exc_page_fault+0x26/0x30 RIP: 0010:rep_movs_alternative+0x30/0x90 Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 1d 2e 04 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 RSP: 0018:ffff88801efe7e00 EFLAGS: 00050202 RAX: 0000000000000001 RBX: 0000000020ffc000 RCX: 0000000000000018 RDX: ffffed1003dfcfce RSI: 0000000020ffc000 RDI: ffff88801efe7e58 RBP: 0000000000000018 R08: 0000000000000001 R09: ffffed1003dfcfcd R10: ffff88801efe7e6f R11: 0000000000000030 R12: 0000000000000000 R13: ffff88801efe7e58 R14: ffff88801efe7e58 R15: 0000000000000000 _copy_from_user+0x9c/0xd0 __x64_sys_sigaltstack+0xeb/0x380 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff5ca846b19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff5c7dbc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000083 RAX: ffffffffffffffda RBX: 00007ff5ca959f60 RCX: 00007ff5ca846b19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020ffc000 RBP: 00007ff5c7dbc1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe0cc447df R14: 00007ff5c7dbc300 R15: 0000000000022000 loop7: detected capacity change from 0 to 4 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 UID: 0 PID: 4493 Comm: syz-executor.5 Tainted: G W 6.19.0-rc5-next-20260116 #1 PREEMPT(lazy) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xfa/0x120 should_fail_ex+0x4d7/0x5e0 should_failslab+0xc2/0x120 kmem_cache_alloc_noprof+0x80/0x760 ptlock_alloc+0x21/0x70 pte_alloc_one+0x86/0x3f0 __pte_alloc+0x6c/0x3f0 __handle_mm_fault+0x246e/0x2fa0 handle_mm_fault+0x2d8/0x750 do_user_addr_fault+0x3cc/0x12b0 exc_page_fault+0xb0/0x180 asm_exc_page_fault+0x26/0x30 RIP: 0010:rep_movs_alternative+0x30/0x90 Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 1d 2e 04 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 RSP: 0018:ffff88804afd7e00 EFLAGS: 00050202 RAX: 0000000000000001 RBX: 0000000020ffc000 RCX: 0000000000000018 RDX: ffffed10095fafce RSI: 0000000020ffc000 RDI: ffff88804afd7e58 RBP: 0000000000000018 R08: 0000000000000001 R09: ffffed10095fafcd R10: ffff88804afd7e6f R11: 0000000000000030 R12: 0000000000000000 R13: ffff88804afd7e58 R14: ffff88804afd7e58 R15: 0000000000000000 _copy_from_user+0x9c/0xd0 __x64_sys_sigaltstack+0xeb/0x380 do_syscall_64+0xbf/0x420 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff5ca846b19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff5c7dbc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000083 RAX: ffffffffffffffda RBX: 00007ff5ca959f60 RCX: 00007ff5ca846b19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020ffc000 RBP: 00007ff5c7dbc1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe0cc447df R14: 00007ff5c7dbc300 R15: 0000000000022000 loop7: detected capacity change from 0 to 4 ---------------- Code disassembly (best guess): 0: 83 f9 08 cmp $0x8,%ecx 3: 73 25 jae 0x2a 5: 85 c9 test %ecx,%ecx 7: 74 0f je 0x18 9: 8a 06 mov (%rsi),%al b: 88 07 mov %al,(%rdi) d: 48 ff c7 inc %rdi 10: 48 ff c6 inc %rsi 13: 48 ff c9 dec %rcx 16: 75 f1 jne 0x9 18: e9 1d 2e 04 00 jmpq 0x42e3a 1d: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 24: 00 00 00 00 28: 66 90 xchg %ax,%ax * 2a: 48 8b 06 mov (%rsi),%rax <-- trapping instruction 2d: 48 89 07 mov %rax,(%rdi) 30: 48 83 c6 08 add $0x8,%rsi 34: 48 83 c7 08 add $0x8,%rdi 38: 83 e9 08 sub $0x8,%ecx 3b: 74 db je 0x18 3d: 83 f9 08 cmp $0x8,%ecx