================================================================== BUG: KASAN: slab-out-of-bounds in dns_resolver_preparse+0xca9/0xd70 net/dns_resolver/dns_key.c:127 Read of size 1 at addr ffff88802ac43f7c by task syz-executor.0/9489 CPU: 3 PID: 9489 Comm: syz-executor.0 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 dns_resolver_preparse+0xca9/0xd70 net/dns_resolver/dns_key.c:127 __key_create_or_update+0x454/0xe00 security/keys/key.c:842 key_create_or_update+0x42/0x50 security/keys/key.c:1007 __do_sys_add_key+0x29c/0x450 security/keys/keyctl.c:134 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a RIP: 0023:0xf7f85579 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:00000000f7f805ac EFLAGS: 00000292 ORIG_RAX: 000000000000011e RAX: ffffffffffffffda RBX: 00000000200003c0 RCX: 0000000020000040 RDX: 0000000020000080 RSI: 0000000000000004 RDI: 000000000c85c77a RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 9489: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node+0x5c/0x90 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kvmalloc_node+0x99/0x1a0 mm/util.c:617 kvmalloc include/linux/slab.h:738 [inline] __do_sys_add_key+0x1f8/0x450 security/keys/keyctl.c:116 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a The buggy address belongs to the object at ffff88802ac43f78 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes to the right of allocated 4-byte region [ffff88802ac43f78, ffff88802ac43f7c) The buggy address belongs to the physical page: page:ffffea0000ab10c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ac43 ksm flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888013042280 ffffea0000909540 dead000000000003 raw: 0000000000000000 0000000080660066 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5225, tgid 5225 (syz-executor.1), ts 160538095168, free_ts 159765361110 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1544 [inline] get_page_from_freelist+0xa25/0x36d0 mm/page_alloc.c:3312 __alloc_pages+0x22e/0x2420 mm/page_alloc.c:4568 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab mm/slub.c:2017 [inline] new_slab+0x283/0x3c0 mm/slub.c:2070 ___slab_alloc+0x979/0x1500 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x310 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0x4a/0x90 mm/slab_common.c:1027 kstrdup+0x3c/0x70 mm/util.c:62 kstrdup_const+0x5f/0x70 mm/util.c:85 __kernfs_new_node+0x9c/0x890 fs/kernfs/dir.c:611 kernfs_new_node fs/kernfs/dir.c:679 [inline] kernfs_create_dir_ns+0x9a/0x210 fs/kernfs/dir.c:1040 sysfs_create_dir_ns+0x13b/0x2b0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x2c8/0x970 lib/kobject.c:238 kobject_add_varg lib/kobject.c:372 [inline] kobject_init_and_add+0x11c/0x190 lib/kobject.c:455 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1137 [inline] free_unref_page_prepare+0x4fa/0xaa0 mm/page_alloc.c:2347 free_unref_page_list+0xe6/0xb40 mm/page_alloc.c:2533 shrink_folio_list+0x2818/0x3f00 mm/vmscan.c:1487 evict_folios+0x6e7/0x1b90 mm/vmscan.c:4499 try_to_shrink_lruvec+0x638/0xa10 mm/vmscan.c:4704 shrink_one+0x3e6/0x7a0 mm/vmscan.c:4743 shrink_many mm/vmscan.c:4808 [inline] lru_gen_shrink_node mm/vmscan.c:4923 [inline] shrink_node+0x211c/0x3710 mm/vmscan.c:5863 kswapd_shrink_node mm/vmscan.c:6668 [inline] balance_pgdat+0x9d2/0x1a90 mm/vmscan.c:6858 kswapd+0x5be/0xbf0 mm/vmscan.c:7118 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Memory state around the buggy address: ffff88802ac43e00: fc fc fa fc fc fc fc 05 fc fc fc fc 05 fc fc fc ffff88802ac43e80: fc 06 fc fc fc fc fa fc fc fc fc fa fc fc fc fc >ffff88802ac43f00: 05 fc fc fc fc fb fc fc fc fc fb fc fc fc fc 04 ^ ffff88802ac43f80: fc fc fc fc fb fc fc fc fc 05 fc fc fc fc fc fc ffff88802ac44000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- 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