Hello, syzbot found the following issue on: HEAD commit: 0de63bb7d919 Merge tag 'pull-fix' of git://git.kernel.org/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=128b4f64580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c48f582603dcb16c dashboard link: https://syzkaller.appspot.com/bug?extid=1b49c591bd17d5732417 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-0de63bb7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4dd046669a28/vmlinux-0de63bb7.xz kernel image: https://storage.googleapis.com/syzbot-assets/4d33e4954ef0/bzImage-0de63bb7.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1b49c591bd17d5732417@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline] BUG: KASAN: slab-use-after-free in atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:1536 [inline] BUG: KASAN: slab-use-after-free in folio_get_anon_vma+0x1e2/0x760 mm/rmap.c:512 Write of size 4 at addr ffff88802294aa30 by task kcompactd0/44 CPU: 2 UID: 0 PID: 44 Comm: kcompactd0 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:1536 [inline] folio_get_anon_vma+0x1e2/0x760 mm/rmap.c:512 migrate_folio_unmap mm/migrate.c:1280 [inline] migrate_pages_batch+0xd68/0x3150 mm/migrate.c:1866 migrate_pages_sync+0x109/0x8f0 mm/migrate.c:1989 migrate_pages+0x1acf/0x2290 mm/migrate.c:2098 compact_zone+0x1f66/0x4220 mm/compaction.c:2663 compact_node+0x1a2/0x2d0 mm/compaction.c:2932 kcompactd+0x707/0xd40 mm/compaction.c:3226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 5954: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1c8/0x3b0 mm/slub.c:4171 anon_vma_alloc mm/rmap.c:94 [inline] anon_vma_fork+0xe6/0x620 mm/rmap.c:360 dup_mmap kernel/fork.c:711 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm+0x1b7b/0x2730 kernel/fork.c:1752 copy_process+0x3e6d/0x6f20 kernel/fork.c:2403 kernel_clone+0xfd/0x960 kernel/fork.c:2815 __do_compat_sys_ia32_clone+0xb7/0x100 arch/x86/kernel/sys_ia32.c:254 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 29: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free_after_rcu_debug+0x115/0x340 mm/slub.c:4659 rcu_do_batch kernel/rcu/tree.c:2546 [inline] rcu_core+0x79d/0x14d0 kernel/rcu/tree.c:2802 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561 run_ksoftirqd kernel/softirq.c:950 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:942 smpboot_thread_fn+0x661/0xa30 kernel/smpboot.c:164 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xb8/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2314 [inline] slab_free mm/slub.c:4609 [inline] kmem_cache_free+0x166/0x4d0 mm/slub.c:4711 anon_vma_free mm/rmap.c:137 [inline] __put_anon_vma+0x114/0x3a0 mm/rmap.c:2568 put_anon_vma include/linux/rmap.h:116 [inline] unlink_anon_vmas+0x58a/0x820 mm/rmap.c:444 free_pgtables+0x12c/0x950 mm/memory.c:387 exit_mmap+0x406/0xba0 mm/mmap.c:1295 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2d70 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __ia32_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 ia32_sys_call+0x1b1c/0x1c20 arch/x86/include/generated/asm/syscalls_32.h:253 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff88802294a990 which belongs to the cache anon_vma of size 208 The buggy address is located 160 bytes inside of freed 208-byte region [ffff88802294a990, ffff88802294aa60) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2294a head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888023092001 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b051cc0 ffffea000126e600 dead000000000002 raw: 0000000000000000 00000000801e001e 00000000f5000000 ffff888023092001 head: 00fff00000000040 ffff88801b051cc0 ffffea000126e600 dead000000000002 head: 0000000000000000 00000000801e001e 00000000f5000000 ffff888023092001 head: 00fff00000000001 ffffea00008a5281 ffffffffffffffff 0000000000000000 head: 0000000000000002 0000000000000000 00000000ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 16720319341, free_ts 16101426947 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x23d/0x330 mm/slub.c:2640 ___slab_alloc+0xbfa/0x1600 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] kmem_cache_alloc_noprof+0xeb/0x3b0 mm/slub.c:4171 anon_vma_alloc mm/rmap.c:94 [inline] __anon_vma_prepare+0x344/0x5e0 mm/rmap.c:202 __vmf_anon_prepare+0x11c/0x240 mm/memory.c:3389 vmf_anon_prepare mm/internal.h:372 [inline] do_anonymous_page mm/memory.c:4875 [inline] do_pte_missing+0x1032/0x3e10 mm/memory.c:4045 handle_pte_fault mm/memory.c:5889 [inline] __handle_mm_fault+0x1166/0x2c60 mm/memory.c:6032 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6201 faultin_page mm/gup.c:1196 [inline] __get_user_pages+0x773/0x36f0 mm/gup.c:1491 __get_user_pages_locked mm/gup.c:1757 [inline] get_user_pages_remote+0x25e/0xb30 mm/gup.c:2661 get_arg_page+0xf3/0x310 fs/exec.c:217 page last free pid 63 tgid 63 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 vfree+0x174/0x950 mm/vmalloc.c:3383 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3303 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff88802294a900: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff88802294a980: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802294aa00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88802294aa80: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ffff88802294ab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
