================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x749/0xaa0 fs/jfs/jfs_txnmgr.c:2737 Read of size 4 at addr ffff888057e9b094 by task jfsCommit/112 CPU: 1 UID: 0 PID: 112 Comm: jfsCommit Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 jfs_lazycommit+0x749/0xaa0 fs/jfs/jfs_txnmgr.c:2737 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 14294: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5382 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] jfs_fill_super+0xc2/0xd80 fs/jfs/super.c:452 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3839 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5833: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2692 [inline] slab_free mm/slub.c:6167 [inline] kfree+0x1c1/0x630 mm/slub.c:6485 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888057e9b000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff888057e9b000, ffff888057e9b100) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x57e9a head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b02fb40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b02fb40 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea00015fa681 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 14203, tgid 14202 (syz.2.2236), ts 848389916750, free_ts 847799042260 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1892 prep_new_page mm/page_alloc.c:1900 [inline] get_page_from_freelist+0x23a1/0x2440 mm/page_alloc.c:3965 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5253 alloc_slab_page mm/slub.c:3296 [inline] allocate_slab+0x77/0x660 mm/slub.c:3485 new_slab mm/slub.c:3543 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7177 refill_sheaf mm/slub.c:2818 [inline] __pcs_replace_empty_main+0x2cd/0x650 mm/slub.c:4618 alloc_from_pcs mm/slub.c:4719 [inline] slab_alloc_node mm/slub.c:4853 [inline] __do_kmalloc_node mm/slub.c:5261 [inline] __kmalloc_noprof+0x474/0x760 mm/slub.c:5274 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] iter_file_splice_write+0x1da/0x10f0 fs/splice.c:678 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x101/0x160 fs/splice.c:1159 splice_direct_to_actor+0x53a/0xc70 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x195/0x290 fs/splice.c:1228 do_sendfile+0x535/0x7d0 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 14179 tgid 14159 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1436 [inline] __free_frozen_pages+0xbe2/0xd60 mm/page_alloc.c:2981 tlb_batch_list_free mm/mmu_gather.c:161 [inline] tlb_finish_mmu+0x144/0x230 mm/mmu_gather.c:552 exit_mmap+0x498/0xa10 mm/mmap.c:1315 __mmput+0x118/0x430 kernel/fork.c:1179 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x8b9/0x2580 kernel/exit.c:962 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3032 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888057e9af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888057e9b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888057e9b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888057e9b100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888057e9b180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================