================================================================== BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x74b/0xa90 fs/jfs/jfs_txnmgr.c:2736 Read of size 4 at addr ffff88805a2cc694 by task jfsCommit/116 CPU: 1 UID: 0 PID: 116 Comm: jfsCommit Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xb4/0x290 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 jfs_lazycommit+0x74b/0xa90 fs/jfs/jfs_txnmgr.c:2736 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 9991: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] jfs_fill_super+0xc2/0xd90 fs/jfs/super.c:452 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1636 vfs_get_tree+0x8f/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3884 do_mount fs/namespace.c:4224 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8758: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x193/0x440 mm/slub.c:4841 generic_shutdown_super+0x132/0x2c0 fs/super.c:642 kill_block_super+0x44/0x90 fs/super.c:1710 deactivate_locked_super+0xb9/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1435 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805a2cc600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 148 bytes inside of freed 256-byte region [ffff88805a2cc600, ffff88805a2cc700) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a2cc 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 ffff88801a041b40 ffffea0000a2e980 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a041b40 ffffea0000a2e980 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea000168b301 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5189, tgid 5189 (udevd), ts 89864455048, free_ts 26866977394 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2618 new_slab mm/slub.c:2672 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858 __slab_alloc mm/slub.c:3948 [inline] __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] smk_fetch+0x95/0x140 security/smack/smack_lsm.c:286 smack_d_instantiate+0x837/0x940 security/smack/smack_lsm.c:3642 security_d_instantiate+0x10a/0x200 security/security.c:4079 d_splice_alias+0x6e/0x330 fs/dcache.c:2989 lookup_open fs/namei.c:3679 [inline] open_last_lookups fs/namei.c:3800 [inline] path_openat+0x10fe/0x3830 fs/namei.c:4036 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2725 __free_pages mm/page_alloc.c:5080 [inline] free_contig_range+0x159/0x440 mm/page_alloc.c:6936 destroy_args+0x86/0x460 mm/debug_vm_pgtable.c:1017 debug_vm_pgtable+0x3cf/0x410 mm/debug_vm_pgtable.c:1397 do_one_initcall+0x233/0x820 init/main.c:1257 do_initcall_level+0x137/0x1f0 init/main.c:1319 do_initcalls+0x69/0xd0 init/main.c:1335 kernel_init_freeable+0x3d9/0x570 init/main.c:1567 kernel_init+0x1d/0x1d0 init/main.c:1457 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88805a2cc580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805a2cc600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a2cc680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a2cc700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805a2cc780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================