------------[ cut here ]------------ percpu ref (free_ioctx_reqs) <= 0 (0) after switching to atomic WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#0: syz-executor.1/3973 Modules linked in: CPU: 0 UID: 0 PID: 3973 Comm: syz-executor.1 Tainted: G W 6.17.0-rc3-next-20250829 #1 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:percpu_ref_switch_to_atomic_rcu+0x3cc/0x480 Code: 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 9e 00 00 00 49 8b 75 e8 48 c7 c7 80 97 e2 84 e8 75 c5 e9 fe 90 <0f> 0b 90 90 e9 2b ff ff ff e8 f6 de 5f ff e9 9e fe ff ff e8 7c df RSP: 0018:ffff88806ce08e20 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8139de70 RDX: ffff8880198a8000 RSI: ffffffff8139de7e RDI: 0000000000000001 RBP: 8000000000000000 R08: 0000000000000001 R09: ffffed100d9c4801 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800a692a00 R13: ffff88800a692a20 R14: 0000000000000002 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880e55dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd9d905fe8 CR3: 0000000042c65000 CR4: 0000000000350ef0 Call Trace: rcu_core+0x7c8/0x1800 handle_softirqs+0x1b1/0x770 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x80 Code: 4a 03 48 c7 c0 f4 ff ff ff eb 92 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 <65> 48 8b 15 88 48 10 06 65 8b 05 99 48 10 06 a9 00 01 ff 00 74 27 RSP: 0018:ffff888047097620 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffea0000e00100 RCX: ffffffff81a2801d RDX: ffff8880198a8000 RSI: ffffffff81a28093 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000000 R09: fffff940001c0020 R10: 0000000000000000 R11: 0000000000000001 R12: ffffea0000e00100 R13: 0000000000000000 R14: ffff88800d86b140 R15: ffffea0000e00130 folio_remove_rmap_ptes+0x283/0x7c0 unmap_page_range+0x15fc/0x36d0 unmap_single_vma.constprop.0+0x153/0x230 unmap_vmas+0x1d6/0x430 exit_mmap+0x181/0xaa0 mmput+0xd5/0x390 do_exit+0x79d/0x2970 do_group_exit+0xd3/0x2a0 get_signal+0x2315/0x2340 arch_do_signal_or_restart+0x80/0x790 exit_to_user_mode_loop+0x8b/0x110 do_syscall_64+0x2f7/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe7b8153b19 Code: Unable to access opcode bytes at 0x7fe7b8153aef. RSP: 002b:00007fe7b56a8218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fe7b8267028 RCX: 00007fe7b8153b19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe7b826702c RBP: 00007fe7b8267020 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 00007fe7b826702c R13: 00007fffa3c4326f R14: 00007fe7b56a8300 R15: 0000000000022000 irq event stamp: 1328 hardirqs last enabled at (1336): [] __up_console_sem+0x78/0x80 hardirqs last disabled at (1345): [] __up_console_sem+0x5d/0x80 softirqs last enabled at (488): [] handle_softirqs+0x50c/0x770 softirqs last disabled at (529): [] __irq_exit_rcu+0xc4/0x100 ---[ end trace 0000000000000000 ]--- percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88800a692a00 pointer offset 0 size 64 loop2: detected capacity change from 0 to 2048 EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. ext4 filesystem being mounted at /syzkaller-testdir350410261/syzkaller.Lisx2q/4/file0 supports timestamps until 2038-01-19 (0x7fffffff) loop7: detected capacity change from 0 to 264192 FAT-fs (loop7): invalid media value (0x08) FAT-fs (loop7): Can't find a valid FAT filesystem kmemleak: Found object by alias at 0x607f1a639c4c CPU: 0 UID: 0 PID: 3967 Comm: syz-executor.6 Tainted: G W 6.17.0-rc3-next-20250829 #1 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xca/0x120 __lookup_object+0x94/0xb0 delete_object_full+0x27/0x70 free_percpu+0x30/0x1160 futex_hash_free+0x38/0xc0 mmput+0x2d3/0x390 do_exit+0x79d/0x2970 do_group_exit+0xd3/0x2a0 __x64_sys_exit_group+0x3e/0x50 x64_sys_call+0x18c5/0x18d0 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3b4bba4b19 Code: Unable to access opcode bytes at 0x7f3b4bba4aef. RSP: 002b:00007ffe05ef0598 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007f3b4bba4b19 RDX: 00007f3b4bb5772b RSI: ffffffffffffffbc RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000001 R15: 00007ffe05ef0680 kmemleak: Object (percpu) 0x607f1a639c48 (size 8): kmemleak: comm "syz-executor.2", pid 3982, jiffies 4294823270 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 percpu_ref_init+0x37/0x400 blkg_alloc+0xe9/0x7d0 blkg_create+0xe08/0x1420 bio_associate_blkg_from_css+0xe06/0x1380 bio_associate_blkg+0x10e/0x2a0 bio_init+0x2dd/0x570 bio_alloc_bioset+0x2cf/0x8c0 submit_bh_wbc+0x286/0x720 ext4_read_bh+0x15a/0x2e0 ext4_read_bh_lock+0x7a/0xd0 ext4_sb_bread_unmovable+0x172/0x260 ext4_fill_super+0x662/0xba20 get_tree_bdev_flags+0x38a/0x620 vfs_get_tree+0x93/0x340 path_mount+0x132d/0x1dd0 audit: type=1400 audit(1756572493.568:11): avc: denied { watch_reads } for pid=3992 comm="syz-executor.1" path="/syzkaller-testdir080923812/syzkaller.BXrygC/3/file0" dev="hugetlbfs" ino=5470 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:hugetlbfs_t:s0 tclass=dir permissive=1 kmemleak: Cannot insert 0x607f1a639c4c into the object search tree (overlaps existing) CPU: 1 UID: 0 PID: 3994 Comm: syz-executor.1 Tainted: G W 6.17.0-rc3-next-20250829 #1 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0xca/0x120 __link_object+0x190/0x210 __create_object+0x48/0x80 pcpu_alloc_noprof+0x87a/0x1170 __percpu_init_rwsem+0x2d/0x160 alloc_super+0x29e/0xb80 sget_fc+0xfe/0xb80 get_tree_nodev+0x28/0x190 hugetlbfs_get_tree+0x23b/0x5a0 vfs_get_tree+0x93/0x340 path_mount+0x132d/0x1dd0 __x64_sys_mount+0x27b/0x300 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe7b8153b19 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:00007fe7b56c9188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe7b8266f60 RCX: 00007fe7b8153b19 RDX: 0000000020000200 RSI: 00000000200000c0 RDI: 0000000000000000 RBP: 00007fe7b81adf6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa3c4326f R14: 00007fe7b56c9300 R15: 0000000000022000 kmemleak: Kernel memory leak detector disabled kmemleak: Object (percpu) 0x607f1a639c48 (size 8): kmemleak: comm "syz-executor.2", pid 3982, jiffies 4294823270 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 percpu_ref_init+0x37/0x400 blkg_alloc+0xe9/0x7d0 blkg_create+0xe08/0x1420 bio_associate_blkg_from_css+0xe06/0x1380 bio_associate_blkg+0x10e/0x2a0 bio_init+0x2dd/0x570 bio_alloc_bioset+0x2cf/0x8c0 submit_bh_wbc+0x286/0x720 ext4_read_bh+0x15a/0x2e0 ext4_read_bh_lock+0x7a/0xd0 ext4_sb_bread_unmovable+0x172/0x260 ext4_fill_super+0x662/0xba20 get_tree_bdev_flags+0x38a/0x620 vfs_get_tree+0x93/0x340 path_mount+0x132d/0x1dd0 loop7: detected capacity change from 0 to 264192 tmpfs: Bad value for 'nr_inodes' loop7: detected capacity change from 0 to 264192 FAT-fs (loop7): invalid media value (0x08) FAT-fs (loop7): Can't find a valid FAT filesystem kmemleak: Automatic memory scanning thread ended Bluetooth: Unexpected continuation frame (len 16) EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000. Bluetooth: Unexpected continuation frame (len 16) audit: type=1400 audit(1756572493.689:12): avc: denied { watch_reads } for pid=3992 comm="syz-executor.1" path="/syzkaller-testdir080923812/syzkaller.BXrygC/3/file0" dev="sda" ino=15991 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=dir permissive=1 loop7: detected capacity change from 0 to 264192 tmpfs: Bad value for 'nr_inodes' UDPLite6: UDP-Lite is deprecated and scheduled to be removed in 2025, please contact the netdev mailing list Bluetooth: hci5: Controller not accepting commands anymore: ncmd = 0 Bluetooth: hci5: Injecting HCI hardware error event Bluetooth: hci5: hardware error 0x00 Bluetooth: hci5: Opcode 0x0c03 failed: -110 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 48 c7 c0 f4 ff ff ff mov $0xfffffffffffffff4,%rax 7: eb 92 jmp 0xffffff9b 9: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: f3 0f 1e fa endbr64 24: 48 8b 34 24 mov (%rsp),%rsi * 28: 65 48 8b 15 88 48 10 mov %gs:0x6104888(%rip),%rdx # 0x61048b8 <-- trapping instruction 2f: 06 30: 65 8b 05 99 48 10 06 mov %gs:0x6104899(%rip),%eax # 0x61048d0 37: a9 00 01 ff 00 test $0xff0100,%eax 3c: 74 27 je 0x65