================================================================== BUG: KASAN: slab-use-after-free in __ref_is_percpu include/linux/percpu-refcount.h:174 [inline] BUG: KASAN: slab-use-after-free in percpu_ref_put_many include/linux/percpu-refcount.h:332 [inline] BUG: KASAN: slab-use-after-free in percpu_ref_put+0xda/0x250 include/linux/percpu-refcount.h:351 Read of size 8 at addr ffff88803cd1e0b0 by task kworker/u4:1/12 CPU: 0 UID: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.11.0-syzkaller-02574-ga430d95c5efa #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: loop0 loop_rootcg_workfn Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __ref_is_percpu include/linux/percpu-refcount.h:174 [inline] percpu_ref_put_many include/linux/percpu-refcount.h:332 [inline] percpu_ref_put+0xda/0x250 include/linux/percpu-refcount.h:351 blk_update_request+0x5e5/0x1160 block/blk-mq.c:925 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1053 loop_handle_cmd drivers/block/loop.c:1927 [inline] loop_process_work+0x1c10/0x2170 drivers/block/loop.c:1945 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x870/0xd30 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 5108: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4190 kmalloc_noprof include/linux/slab.h:690 [inline] kzalloc_noprof include/linux/slab.h:816 [inline] __bch2_dev_alloc+0x57/0xa60 fs/bcachefs/super.c:1288 bch2_dev_alloc+0xd4/0x170 fs/bcachefs/super.c:1358 bch2_fs_alloc+0x1f7c/0x20b0 fs/bcachefs/super.c:938 bch2_fs_open+0x8cc/0xdf0 fs/bcachefs/super.c:2115 bch2_fs_get_tree+0x731/0x1700 fs/bcachefs/fs.c:1943 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 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 Freed by task 5108: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2250 [inline] slab_free mm/slub.c:4474 [inline] kfree+0x149/0x360 mm/slub.c:4595 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22f/0x480 lib/kobject.c:737 bch2_fs_free+0x27b/0x3c0 fs/bcachefs/super.c:666 bch2_fs_get_tree+0xd98/0x1700 fs/bcachefs/fs.c:2051 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 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 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 insert_work+0x3e/0x330 kernel/workqueue.c:2185 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2341 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:621 [inline] bch2_dev_do_invalidates+0x17a/0x1f0 fs/bcachefs/alloc_background.c:2149 bch2_do_invalidates+0x29/0x60 fs/bcachefs/alloc_background.c:2160 __bch2_fs_read_write+0x34c/0x370 fs/bcachefs/super.c:498 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:183 bch2_run_recovery_passes+0x19e/0x820 fs/bcachefs/recovery_passes.c:230 bch2_fs_recovery+0x24f9/0x38b0 fs/bcachefs/recovery.c:859 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1036 bch2_fs_get_tree+0xd61/0x1700 fs/bcachefs/fs.c:1956 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 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 Second to last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 insert_work+0x3e/0x330 kernel/workqueue.c:2185 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2341 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2392 queue_work include/linux/workqueue.h:621 [inline] bch2_dev_do_discards+0x17a/0x1f0 fs/bcachefs/alloc_background.c:1891 bch2_do_discards+0x29/0x60 fs/bcachefs/alloc_background.c:1902 __bch2_fs_read_write+0x344/0x370 fs/bcachefs/super.c:497 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:183 bch2_run_recovery_passes+0x19e/0x820 fs/bcachefs/recovery_passes.c:230 bch2_fs_recovery+0x24f9/0x38b0 fs/bcachefs/recovery.c:859 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1036 bch2_fs_get_tree+0xd61/0x1700 fs/bcachefs/fs.c:1956 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 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 The buggy address belongs to the object at ffff88803cd1e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 176 bytes inside of freed 4096-byte region [ffff88803cd1e000, ffff88803cd1f000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3cd18 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 04fff00000000040 ffff88801ac42140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000001fdffffff 0000000000000000 head: 04fff00000000040 ffff88801ac42140 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000001fdffffff 0000000000000000 head: 04fff00000000003 ffffea0000f34601 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5108, tgid 5107 (syz.0.0), ts 81365488506, free_ts 79616321792 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1500 prep_new_page mm/page_alloc.c:1508 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3446 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4702 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2319 allocate_slab+0x5a/0x2f0 mm/slub.c:2482 new_slab mm/slub.c:2535 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3721 __slab_alloc+0x58/0xa0 mm/slub.c:3811 __slab_alloc_node mm/slub.c:3864 [inline] slab_alloc_node mm/slub.c:4026 [inline] __do_kmalloc_node mm/slub.c:4158 [inline] __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4165 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:650 btree_node_data_alloc+0x151/0x260 fs/bcachefs/btree_cache.c:109 __bch2_btree_node_mem_alloc+0x1e1/0x3b0 fs/bcachefs/btree_cache.c:150 bch2_fs_btree_cache_init+0x269/0x570 fs/bcachefs/btree_cache.c:560 bch2_fs_alloc+0x1c49/0x20b0 fs/bcachefs/super.c:917 bch2_fs_open+0x8cc/0xdf0 fs/bcachefs/super.c:2115 bch2_fs_get_tree+0x731/0x1700 fs/bcachefs/fs.c:1943 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 page last free pid 5092 tgid 5092 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1101 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2619 discard_slab mm/slub.c:2581 [inline] __put_partials+0xeb/0x130 mm/slub.c:3049 put_cpu_partial+0x17c/0x250 mm/slub.c:3124 __slab_free+0x2ea/0x3d0 mm/slub.c:4344 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3989 [inline] slab_alloc_node mm/slub.c:4038 [inline] __kmalloc_cache_noprof+0x132/0x2c0 mm/slub.c:4185 kmalloc_noprof include/linux/slab.h:690 [inline] kzalloc_noprof include/linux/slab.h:816 [inline] nsim_fib4_rt_create drivers/net/netdevsim/fib.c:280 [inline] nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:426 [inline] nsim_fib4_event drivers/net/netdevsim/fib.c:464 [inline] nsim_fib_event drivers/net/netdevsim/fib.c:884 [inline] nsim_fib_event_work+0xe1a/0x4130 drivers/net/netdevsim/fib.c:1492 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x870/0xd30 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff88803cd1df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803cd1e000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803cd1e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803cd1e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803cd1e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================