================================================================== BUG: KASAN: use-after-free in jfs_lazycommit+0x7da/0xb20 fs/jfs/jfs_txnmgr.c:2735 Read of size 4 at addr ffff88807c896094 by task jfsCommit/84 CPU: 0 PID: 84 Comm: jfsCommit Not tainted 6.1.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x210/0x2fc lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 jfs_lazycommit+0x7da/0xb20 fs/jfs/jfs_txnmgr.c:2735 kthread+0x264/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Allocated by task 5219: 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:556 [inline] kzalloc include/linux/slab.h:692 [inline] jfs_fill_super+0xfb/0xc40 fs/jfs/super.c:495 mount_bdev+0x2ad/0x3b0 fs/super.c:1432 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1562 do_new_mount+0x2ba/0xb40 fs/namespace.c:3051 do_mount fs/namespace.c:3394 [inline] __do_sys_mount fs/namespace.c:3602 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3579 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 2523: 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+0x27d/0x3d0 mm/slub.c:3674 generic_shutdown_super+0x128/0x340 fs/super.c:501 kill_block_super+0x7a/0xe0 fs/super.c:1459 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x3fb/0x480 fs/namespace.c:1186 task_work_run+0x246/0x2f0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xbd/0xe0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x6c/0xf0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x28/0x1f0 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807c896000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of 256-byte region [ffff88807c896000, ffff88807c896100) The buggy address belongs to the physical page: page:ffffea0001f22580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c896 head:ffffea0001f22580 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000679700 dead000000000004 ffff88800b441b40 raw: 0000000000000000 0000000080100010 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 5107, tgid 5106 (syz-executor.0), ts 114389924656, free_ts 114335528618 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x100/0x120 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x3225/0x33b0 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5547 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x280 mm/slub.c:1992 ___slab_alloc+0x9cb/0xf80 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x195/0x250 mm/slub.c:3437 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1045 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:692 [inline] jfs_fill_super+0xfb/0xc40 fs/jfs/super.c:495 mount_bdev+0x2ad/0x3b0 fs/super.c:1432 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1562 do_new_mount+0x2ba/0xb40 fs/namespace.c:3051 do_mount fs/namespace.c:3394 [inline] __do_sys_mount fs/namespace.c:3602 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3579 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 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1440 [inline] free_pcp_prepare mm/page_alloc.c:1490 [inline] free_unref_page_prepare+0xe10/0xfe0 mm/page_alloc.c:3358 free_unref_page+0x33/0x390 mm/page_alloc.c:3453 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+0x54/0x310 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/0x2c0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] seq_open+0x5e/0x130 fs/seq_file.c:63 kernfs_fop_open+0x600/0xbf0 do_dentry_open+0x7f9/0x10f0 fs/open.c:882 do_open fs/namei.c:3628 [inline] path_openat+0x256c/0x2dd0 fs/namei.c:3785 do_filp_open+0x230/0x480 fs/namei.c:3812 do_sys_openat2+0x13b/0x500 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1345 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: ffff88807c895f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807c896000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807c896080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c896100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807c896180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================