================================================================== BUG: KASAN: use-after-free in jfs_lazycommit+0x7da/0xb60 fs/jfs/jfs_txnmgr.c:2735 Read of size 4 at addr ffff888027015094 by task jfsCommit/108 CPU: 1 PID: 108 Comm: jfsCommit Not tainted 6.1.124-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:427 kasan_report+0x136/0x160 mm/kasan/report.c:531 jfs_lazycommit+0x7da/0xb60 fs/jfs/jfs_txnmgr.c:2735 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 6524: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] jfs_fill_super+0xfb/0xc40 fs/jfs/super.c:495 mount_bdev+0x2c9/0x3f0 fs/super.c:1443 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x2ba/0xb40 fs/namespace.c:3056 do_mount fs/namespace.c:3399 [inline] __do_sys_mount fs/namespace.c:3607 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 4250: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x116/0x8c0 kernel/rcu/tree.c:3401 drop_sysctl_table+0x317/0x460 fs/proc/proc_sysctl.c:1727 drop_sysctl_table+0x329/0x460 fs/proc/proc_sysctl.c:1730 unregister_sysctl_table+0x86/0x130 fs/proc/proc_sysctl.c:1765 lowpan_frags_ns_sysctl_unregister net/ieee802154/6lowpan/reassembly.c:403 [inline] lowpan_frags_exit_net+0x5c/0xb0 net/ieee802154/6lowpan/reassembly.c:476 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x6ce/0xbf0 net/core/net_namespace.c:621 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888027015000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of 256-byte region [ffff888027015000, ffff888027015100) The buggy address belongs to the physical page: page:ffffea00009c0500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27014 head:ffffea00009c0500 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888017c41b40 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5910, tgid 5899 (syz.0.352), ts 305445655527, free_ts 296477432723 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5605 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa1/0x230 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] new_dir fs/proc/proc_sysctl.c:969 [inline] get_subdir fs/proc/proc_sysctl.c:1013 [inline] __register_sysctl_table+0x9f1/0x11e0 fs/proc/proc_sysctl.c:1375 ipv6_sysctl_net_init+0x35d/0x480 net/ipv6/sysctl_net_ipv6.c:283 ops_init+0x35d/0x610 net/core/net_namespace.c:138 setup_net+0x4b5/0xb90 net/core/net_namespace.c:335 copy_net_ns+0x352/0x590 net/core/net_namespace.c:498 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x531/0xa40 kernel/fork.c:3201 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x12a6/0x15b0 mm/page_alloc.c:3384 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3479 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422 mt_alloc_one lib/maple_tree.c:152 [inline] mas_alloc_nodes+0x276/0x800 lib/maple_tree.c:1277 mas_node_count_gfp lib/maple_tree.c:1359 [inline] mas_preallocate+0x12d/0x350 lib/maple_tree.c:5815 vma_expand+0x271/0x8f0 mm/mmap.c:543 __mmap_region mm/mmap.c:2728 [inline] mmap_region+0xe26/0x2660 mm/mmap.c:2904 do_mmap+0x8c5/0xf60 mm/mmap.c:1424 vm_mmap_pgoff+0x1ca/0x2d0 mm/util.c:520 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff888027014f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888027015000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888027015080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888027015100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888027015180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================