================================================================== 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+0x1fdf/0x5270 mm/compaction.c:1180 Read of size 8 at addr ffff8880248f6d48 by task syz.0.677/8125 CPU: 1 UID: 0 PID: 8125 Comm: syz.0.677 Not tainted 6.13.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 kasan_check_range+0x282/0x290 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+0x1fdf/0x5270 mm/compaction.c:1180 isolate_migratepages mm/compaction.c:2164 [inline] compact_zone+0x32e6/0x4ac0 mm/compaction.c:2611 compact_node mm/compaction.c:2910 [inline] compact_nodes mm/compaction.c:2932 [inline] sysctl_compaction_handler+0x496/0x990 mm/compaction.c:2983 proc_sys_call_handler+0x5ec/0x920 fs/proc/proc_sysctl.c:601 iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x11b/0x220 fs/splice.c:1164 splice_direct_to_actor+0x586/0xc80 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x289/0x3e0 fs/splice.c:1233 do_sendfile+0x564/0x8a0 fs/read_write.c:1363 __do_compat_sys_sendfile fs/read_write.c:1439 [inline] __se_compat_sys_sendfile+0x121/0x1f0 fs/read_write.c:1428 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf714d579 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 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f513f55c EFLAGS: 00000206 ORIG_RAX: 00000000000000bb RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000000003 RDX: 00000000200000c0 RSI: 0000000000000005 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6692: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4298 [inline] __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4310 kmalloc_noprof include/linux/slab.h:905 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x236/0x860 security/tomoyo/file.c:723 security_file_ioctl_compat+0xc6/0x2a0 security/security.c:2926 __do_compat_sys_ioctl fs/ioctl.c:956 [inline] __se_compat_sys_ioctl+0xd6/0xc10 fs/ioctl.c:947 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 6692: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x196/0x430 mm/slub.c:4761 tomoyo_realpath_from_path+0x5a9/0x5e0 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x236/0x860 security/tomoyo/file.c:723 security_file_ioctl_compat+0xc6/0x2a0 security/security.c:2926 __do_compat_sys_ioctl fs/ioctl.c:956 [inline] __se_compat_sys_ioctl+0xd6/0xc10 fs/ioctl.c:947 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff8880248f6000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3400 bytes inside of freed 4096-byte region [ffff8880248f6000, ffff8880248f7000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x248f0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888028c5d081 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801ac4f3c0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000080008 00000001f5000000 ffff888028c5d081 head: 00fff00000000040 ffff88801ac4f3c0 dead000000000122 0000000000000000 head: 0000000000000000 0000000000080008 00000001f5000000 ffff888028c5d081 head: 00fff00000000003 ffffea0000923c01 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 6692, tgid 6692 (syz-executor), ts 154325324056, free_ts 154297940357 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3474 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269 alloc_slab_page+0x6a/0x110 mm/slub.c:2423 allocate_slab+0x5a/0x2b0 mm/slub.c:2589 new_slab mm/slub.c:2642 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830 __slab_alloc+0x58/0xa0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4324 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] alloc_tty_struct+0xa9/0x7d0 drivers/tty/tty_io.c:3116 pty_common_install+0x160/0x760 drivers/tty/pty.c:379 tty_driver_install_tty drivers/tty/tty_io.c:1304 [inline] tty_init_dev+0xc1/0x4c0 drivers/tty/tty_io.c:1416 ptmx_open+0xda/0x2c0 drivers/tty/pty.c:824 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xbe1/0x1b70 fs/open.c:945 vfs_open+0x3e/0x330 fs/open.c:1075 page last free pid 6692 tgid 6692 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2657 discard_slab mm/slub.c:2688 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3157 put_cpu_partial+0x17c/0x250 mm/slub.c:3232 __slab_free+0x290/0x380 mm/slub.c:4483 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175 getname_flags+0xb7/0x540 fs/namei.c:139 do_sys_openat2+0xd2/0x1d0 fs/open.c:1396 do_sys_open fs/open.c:1417 [inline] __do_compat_sys_openat fs/open.c:1479 [inline] __se_compat_sys_openat fs/open.c:1477 [inline] __ia32_compat_sys_openat+0x23f/0x290 fs/open.c:1477 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Memory state around the buggy address: ffff8880248f6c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880248f6c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880248f6d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880248f6d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880248f6e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- 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: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop