================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: slab-use-after-free in mapping_inaccessible include/linux/pagemap.h:335 [inline] BUG: KASAN: slab-use-after-free in isolate_migratepages_block+0x3eb3/0x56f0 mm/compaction.c:1182 Read of size 8 at addr ffff888023a76d48 by task syz.7.2748/12398 CPU: 3 UID: 0 PID: 12398 Comm: syz.7.2748 Not tainted 6.14.0-syzkaller-02665-g1e26c5e28ca5 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __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:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] mapping_inaccessible include/linux/pagemap.h:335 [inline] isolate_migratepages_block+0x3eb3/0x56f0 mm/compaction.c:1182 isolate_migratepages mm/compaction.c:2167 [inline] compact_zone+0x1a5e/0x4220 mm/compaction.c:2633 compact_node+0x1a4/0x2d0 mm/compaction.c:2932 compact_nodes mm/compaction.c:2954 [inline] sysctl_compaction_handler mm/compaction.c:3005 [inline] sysctl_compaction_handler+0x141/0x210 mm/compaction.c:2992 proc_sys_call_handler+0x3d0/0x5b0 fs/proc/proc_sysctl.c:601 iter_file_splice_write+0x91c/0x1150 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] direct_splice_actor+0x18f/0x6c0 fs/splice.c:1158 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1227 do_sendfile+0xafd/0xe50 fs/read_write.c:1368 __do_compat_sys_sendfile fs/read_write.c:1444 [inline] __se_compat_sys_sendfile fs/read_write.c:1433 [inline] __ia32_compat_sys_sendfile+0x162/0x220 fs/read_write.c:1433 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] do_int80_emulation+0x104/0x200 arch/x86/entry/syscall_32.c:172 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:626 RIP: 0023:0xf7f44579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f506655c EFLAGS: 00000296 ORIG_RAX: 00000000000000bb RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000000003 RDX: 00000000800000c0 RSI: 0000000000000005 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 12395: 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:4138 [inline] slab_alloc_node mm/slub.c:4187 [inline] kmem_cache_alloc_lru_noprof+0x1d0/0x3b0 mm/slub.c:4206 shmem_alloc_inode+0x25/0x50 mm/shmem.c:5160 alloc_inode+0x61/0x240 fs/inode.c:346 new_inode+0x22/0x1c0 fs/inode.c:1145 __shmem_get_inode mm/shmem.c:3058 [inline] shmem_get_inode+0x19a/0xfb0 mm/shmem.c:3132 shmem_symlink+0xf7/0x780 mm/shmem.c:4107 vfs_symlink fs/namei.c:4688 [inline] vfs_symlink+0x400/0x680 fs/namei.c:4672 do_symlinkat+0x261/0x310 fs/namei.c:4714 __do_sys_symlinkat fs/namei.c:4730 [inline] __se_sys_symlinkat fs/namei.c:4727 [inline] __ia32_sys_symlinkat+0x93/0xc0 fs/namei.c:4727 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 15: 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:2376 [inline] slab_free mm/slub.c:4633 [inline] kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4735 i_callback+0x43/0x70 fs/inode.c:325 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0x799/0x14e0 kernel/rcu/tree.c:2824 handle_softirqs+0x216/0x8e0 kernel/softirq.c:561 run_ksoftirqd kernel/softirq.c:950 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:942 smpboot_thread_fn+0x678/0xa70 kernel/smpboot.c:164 kthread+0x3a4/0x760 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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 __call_rcu_common.constprop.0+0x9a/0x9f0 kernel/rcu/tree.c:3082 destroy_inode+0x12c/0x1b0 fs/inode.c:401 evict+0x5b4/0x920 fs/inode.c:834 iput_final fs/inode.c:1898 [inline] iput fs/inode.c:1924 [inline] iput+0x521/0x880 fs/inode.c:1910 do_unlinkat+0x518/0x6a0 fs/namei.c:4615 __do_sys_unlink fs/namei.c:4654 [inline] __se_sys_unlink fs/namei.c:4652 [inline] __ia32_sys_unlink+0xc4/0x110 fs/namei.c:4652 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888023a76880 which belongs to the cache shmem_inode_cache of size 1544 The buggy address is located 1224 bytes inside of freed 1544-byte region [ffff888023a76880, ffff888023a76e88) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23a70 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff8880251ee101 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801c2bdcc0 0000000000000000 0000000000000001 raw: 0000000000000000 0000000000130013 00000000f5000000 ffff8880251ee101 head: 00fff00000000040 ffff88801c2bdcc0 0000000000000000 0000000000000001 head: 0000000000000000 0000000000130013 00000000f5000000 ffff8880251ee101 head: 00fff00000000003 ffffea00008e9c01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 36, tgid 36 (kdevtmpfs), ts 6567016539, free_ts 0 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+0x10c4/0x34c0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x223/0x24d0 mm/page_alloc.c:4740 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2446 [inline] allocate_slab mm/slub.c:2610 [inline] new_slab+0x23c/0x330 mm/slub.c:2663 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3849 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3939 __slab_alloc_node mm/slub.c:4014 [inline] slab_alloc_node mm/slub.c:4175 [inline] kmem_cache_alloc_lru_noprof+0xf4/0x3b0 mm/slub.c:4206 shmem_alloc_inode+0x25/0x50 mm/shmem.c:5160 alloc_inode+0x61/0x240 fs/inode.c:346 new_inode+0x22/0x1c0 fs/inode.c:1145 __shmem_get_inode mm/shmem.c:3058 [inline] shmem_get_inode+0x19a/0xfb0 mm/shmem.c:3132 shmem_mknod+0x1a8/0x450 mm/shmem.c:3854 vfs_mknod+0x5d7/0x8e0 fs/namei.c:4193 handle_create drivers/base/devtmpfs.c:233 [inline] handle drivers/base/devtmpfs.c:393 [inline] devtmpfs_work_loop+0x1c8/0x8e0 drivers/base/devtmpfs.c:408 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:450 page_owner free stack trace missing Memory state around the buggy address: ffff888023a76c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023a76c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888023a76d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888023a76d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888023a76e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi