================================================================== 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 ffff88802135c004 by task syz-executor.1/833 CPU: 0 PID: 833 Comm: syz-executor.1 Not tainted 6.7.0-rc6-syzkaller-00303-g3f82f1c3a036 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 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_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f9e8ac7cce9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9e8b9810c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8 RAX: ffffffffffffffda RBX: 00007f9e8ad9bf80 RCX: 00007f9e8ac7cce9 RDX: 0000000020000080 RSI: 0000000000000000 RDI: 00000000200003c0 RBP: 00007f9e8acc947a R08: 00000000076f5aa7 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f9e8ad9bf80 R15: 00007ffd6f65f1e8 Allocated by task 833: 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_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff88802135c000 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 [ffff88802135c000, ffff88802135c004) The buggy address belongs to the physical page: page:ffffea000084d700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2135c flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888013041280 dead000000000100 dead000000000122 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 6031, tgid 6031 (udevd), ts 191626323479, free_ts 190650287856 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 kmemdup+0x29/0x60 mm/util.c:131 kmemdup include/linux/fortify-string.h:761 [inline] shmem_symlink+0x243/0x6e0 mm/shmem.c:3497 vfs_symlink fs/namei.c:4464 [inline] vfs_symlink+0x3e4/0x620 fs/namei.c:4448 do_symlinkat+0x25f/0x310 fs/namei.c:4490 __do_sys_symlink fs/namei.c:4511 [inline] __se_sys_symlink fs/namei.c:4509 [inline] __x64_sys_symlink+0x79/0x90 fs/namei.c:4509 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b 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+0x33/0x3b0 mm/page_alloc.c:2487 __unfreeze_partials+0x226/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x15d/0x2f0 mm/slub.c:3502 getname_flags.part.0+0x50/0x4e0 fs/namei.c:140 getname_flags+0x9c/0xf0 include/linux/audit.h:321 user_path_at_empty+0x2c/0x60 fs/namei.c:2910 do_readlinkat+0xdd/0x310 fs/stat.c:494 __do_sys_readlink fs/stat.c:527 [inline] __se_sys_readlink fs/stat.c:524 [inline] __x64_sys_readlink+0x78/0xb0 fs/stat.c:524 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Memory state around the buggy address: ffff88802135bf00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ffff88802135bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802135c000: 04 fc fc fc fc 05 fc fc fc fc 05 fc fc fc fc 05 ^ ffff88802135c080: fc fc fc fc 05 fc fc fc fc 05 fc fc fc fc 07 fc ffff88802135c100: fc fc fc 05 fc fc fc fc 05 fc fc fc fc fb fc fc ==================================================================