syzbot


KASAN: slab-out-of-bounds Read in dns_resolver_preparse

Status: fixed on 2024/01/20 21:18
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
Fix commit: 1997b3cb4217 keys, dns: Fix missing size check of V1 server-list header
First crash: 162d, last: 148d
Cause bisection: introduced by (bisect log) :
commit b946001d3bb1202e90093cf5e72dbcb20e2689a0
Author: David Howells <dhowells@redhat.com>
Date: Sat Dec 9 00:41:55 2023 +0000

  keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry

Crash: KASAN: slab-out-of-bounds Read in dns_resolver_preparse (log)
Repro: C syz .config
  
Discussions (4)
Title Replies (including bot) Last reply
[PATCH] keys, dns: Fix missing size check of V1 server-list header 6 (6) 2024/01/10 05:47
[syzbot] [net?] KASAN: slab-out-of-bounds Read in dns_resolver_preparse 2 (7) 2023/12/23 23:59
Re: [GIT PULL] afs, dns: Fix dynamic root interaction with negative DNS 1 (1) 2023/12/23 17:28
[PATCH next] keys/dns: datalen must greater than sizeof(*v1) 4 (4) 2023/12/16 21:06
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 KASAN: slab-out-of-bounds Read in dns_resolver_preparse origin:lts-only C error 31 129d 135d 0/3 upstream: reported C repro on 2024/01/09 18:29
linux-6.1 KASAN: slab-out-of-bounds Read in dns_resolver_preparse origin:lts-only C inconclusive 16 134d 141d 0/3 upstream: reported C repro on 2024/01/03 14:33
Last patch testing requests (3)
Created Duration User Patch Repo Result
2023/12/23 23:34 23m dhowells@redhat.com patch upstream OK log
2023/12/14 14:18 21m eadavis@qq.com patch https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 48e8992e33ab OK log
2023/12/14 13:59 21m eadavis@qq.com patch https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 48e8992e33ab OK log

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
Read of size 1 at addr ffff888028894084 by task syz-executor265/5069

CPU: 0 PID: 5069 Comm: syz-executor265 Not tainted 6.7.0-rc5-next-20231213-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __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:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
 __key_create_or_update+0x453/0xdf0 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+0x62/0x6a
RIP: 0033:0x7fd37f34f2e9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff2f4f3198 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 00007fff2f4f3368 RCX: 00007fd37f34f2e9
RDX: 0000000020000080 RSI: 0000000000000000 RDI: 00000000200003c0
RBP: 00007fd37f3c2610 R08: 0000000002853c32 R09: 00007fff2f4f3368
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff2f4f3358 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Allocated by task 5069:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
 kasan_set_track+0x24/0x30 mm/kasan/common.c:61
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slub.c:3985 [inline]
 __kmalloc_node+0x226/0x480 mm/slub.c:3992
 kmalloc_node include/linux/slab.h:610 [inline]
 kvmalloc_node+0x99/0x1a0 mm/util.c:617
 kvmalloc include/linux/slab.h:728 [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+0x62/0x6a

The buggy address belongs to the object at ffff888028894080
 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 [ffff888028894080, ffff888028894084)

The buggy address belongs to the physical page:
page:ffffea0000a22500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28894
anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888013041280 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080800080 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 1, tgid 1 (swapper/0), ts 27978623390, free_ts 27978121808
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1540
 prep_new_page mm/page_alloc.c:1547 [inline]
 get_page_from_freelist+0xa19/0x3740 mm/page_alloc.c:3355
 __alloc_pages+0x22e/0x2410 mm/page_alloc.c:4611
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 alloc_slab_page mm/slub.c:2191 [inline]
 allocate_slab mm/slub.c:2358 [inline]
 new_slab+0x283/0x3c0 mm/slub.c:2411
 ___slab_alloc+0x4ab/0x1990 mm/slub.c:3544
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3629
 __slab_alloc_node mm/slub.c:3682 [inline]
 slab_alloc_node mm/slub.c:3854 [inline]
 __do_kmalloc_node mm/slub.c:3984 [inline]
 __kmalloc_node_track_caller+0x367/0x470 mm/slub.c:4005
 kstrdup+0x3c/0x70 mm/util.c:62
 kstrdup_const+0x5f/0x70 mm/util.c:85
 kvasprintf_const+0x10b/0x190 lib/kasprintf.c:48
 kobject_set_name_vargs+0x5a/0x130 lib/kobject.c:272
 kobject_add_varg lib/kobject.c:366 [inline]
 kobject_init_and_add+0xe8/0x190 lib/kobject.c:455
 locate_module_kobject+0xef/0x190 kernel/params.c:781
 kernel_add_sysfs_param kernel/params.c:808 [inline]
 param_sysfs_builtin kernel/params.c:856 [inline]
 param_sysfs_builtin_init+0x25f/0x450 kernel/params.c:990
 do_one_initcall+0x128/0x680 init/main.c:1236
page last free pid 3062 tgid 3062 stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1140 [inline]
 free_unref_page_prepare+0x51f/0xb10 mm/page_alloc.c:2390
 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2530
 mm_free_pgd kernel/fork.c:799 [inline]
 __mmdrop+0xd5/0x470 kernel/fork.c:915
 mmdrop include/linux/sched/mm.h:54 [inline]
 __mmput+0x40a/0x4d0 kernel/fork.c:1352
 mmput+0x62/0x70 kernel/fork.c:1363
 free_bprm+0x143/0x3e0 fs/exec.c:1490
 kernel_execve+0x3e6/0x4e0 fs/exec.c:2036
 call_usermodehelper_exec_async+0x252/0x4c0 kernel/umh.c:110
 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:
 ffff888028893f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888028894000: 07 fc fc fc 07 fc fc fc fa fc fc fc 05 fc fc fc
>ffff888028894080: 04 fc fc fc fb fc fc fc fb fc fc fc 06 fc fc fc
                   ^
 ffff888028894100: 06 fc fc fc fb fc fc fc 00 fc fc fc 00 fc fc fc
 ffff888028894180: fb fc fc fc 04 fc fc fc 04 fc fc fc fb fc fc fc
==================================================================

Crashes (46):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/13 15:59 linux-next 48e8992e33ab ebcad15c .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/27 10:33 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/27 10:33 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/27 10:33 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/27 10:31 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/25 20:52 upstream 861deac3b092 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/25 08:31 upstream 861deac3b092 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/25 02:14 upstream 861deac3b092 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 20:37 upstream 861deac3b092 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 04:52 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 03:15 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 02:14 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:51 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:51 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:46 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:46 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:18 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/22 13:24 upstream 24e0d2e527a3 4f9530a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/22 10:34 upstream 24e0d2e527a3 4f9530a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/27 00:24 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/25 22:17 upstream 861deac3b092 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 02:36 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 02:36 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:16 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/27 10:33 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/27 10:31 linux-next 39676dfe5233 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/25 13:27 linux-next 39676dfe5233 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:25 linux-next 39676dfe5233 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:15 linux-next 39676dfe5233 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:15 linux-next 39676dfe5233 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/22 09:20 linux-next 39676dfe5233 4f9530a3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/19 15:37 linux-next aa4db8324c4d 3ad490ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/19 15:33 linux-next aa4db8324c4d 3ad490ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/19 13:19 linux-next aa4db8324c4d 3ad490ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/19 12:24 linux-next aa4db8324c4d 3ad490ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/14 16:05 linux-next 11651f8cb2e8 3222d10c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/13 15:48 linux-next 48e8992e33ab ebcad15c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/13 15:37 linux-next 48e8992e33ab ebcad15c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in dns_resolver_preparse
2023/12/24 01:21 upstream 3f82f1c3a036 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in dns_resolver_preparse
2023/12/27 00:35 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dns_resolver_preparse
2023/12/25 10:07 upstream 861deac3b092 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in dns_resolver_preparse
* Struck through repros no longer work on HEAD.