syzbot


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

Status: upstream: reported C repro on 2024/04/05 06:55
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+d4ecae01a53fd9b42e7d@syzkaller.appspotmail.com
First crash: 53d, last: 39d
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] net/socket: the length value of the input socket option parameter is too small 11 (11) 2024/04/09 18:27
[syzbot] [bluetooth?] KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt 1 (3) 2024/04/06 00:52
Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/05/02 21:39 23m retest repro upstream OK log
2024/05/02 21:07 32m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2024/04/05 09:31 9h24m eadavis@qq.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git fe46a7dd189e OK log

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline]
BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt_old net/bluetooth/rfcomm/sock.c:632 [inline]
BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt+0x893/0xa70 net/bluetooth/rfcomm/sock.c:673
Read of size 4 at addr ffff8880209a8bc3 by task syz-executor632/5064

CPU: 0 PID: 5064 Comm: syz-executor632 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
 copy_from_sockptr include/linux/sockptr.h:55 [inline]
 rfcomm_sock_setsockopt_old net/bluetooth/rfcomm/sock.c:632 [inline]
 rfcomm_sock_setsockopt+0x893/0xa70 net/bluetooth/rfcomm/sock.c:673
 do_sock_setsockopt+0x3af/0x720 net/socket.c:2311
 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
 __do_sys_setsockopt net/socket.c:2343 [inline]
 __se_sys_setsockopt net/socket.c:2340 [inline]
 __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f36ff898dc9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 18 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe010c2208 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f36ff898dc9
RDX: 0000000000000003 RSI: 0000000000000012 RDI: 0000000000000006
RBP: 0000000000000006 R08: 0000000000000002 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 0000555567399338
R13: 000000000000000e R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 5064:
 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:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slub.c:3966 [inline]
 __kmalloc+0x233/0x4a0 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 __cgroup_bpf_run_filter_setsockopt+0xd2f/0x1040 kernel/bpf/cgroup.c:1869
 do_sock_setsockopt+0x6b4/0x720 net/socket.c:2293
 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
 __do_sys_setsockopt net/socket.c:2343 [inline]
 __se_sys_setsockopt net/socket.c:2340 [inline]
 __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

The buggy address belongs to the object at ffff8880209a8bc0
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 1 bytes to the right of
 allocated 2-byte region [ffff8880209a8bc0, ffff8880209a8bc2)

The buggy address belongs to the physical page:
page:ffffea0000826a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x209a8
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888014c41280 ffffea000081fb80 dead000000000002
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 9917548498, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
 prep_new_page mm/page_alloc.c:1540 [inline]
 get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
 __alloc_pages+0x256/0x680 mm/page_alloc.c:4569
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2175
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2391
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 __do_kmalloc_node mm/slub.c:3965 [inline]
 __kmalloc+0x2e5/0x4a0 mm/slub.c:3979
 kmalloc_array include/linux/slab.h:665 [inline]
 kcalloc include/linux/slab.h:696 [inline]
 group_cpus_evenly+0x294/0x5f0 lib/group_cpus.c:365
 blk_mq_map_queues+0x4c/0x3e0 block/blk-mq-cpumap.c:23
 blk_mq_alloc_tag_set+0x7ac/0xf40 block/blk-mq.c:4521
 nbd_dev_add+0x367/0xc80 drivers/block/nbd.c:1831
 nbd_init+0x224/0x2e0 drivers/block/nbd.c:2593
 do_one_initcall+0x238/0x830 init/main.c:1241
 do_initcall_level+0x157/0x210 init/main.c:1303
 do_initcalls+0x3f/0x80 init/main.c:1319
 kernel_init_freeable+0x435/0x5d0 init/main.c:1550
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880209a8a80: 06 fc fc fc 06 fc fc fc 06 fc fc fc 07 fc fc fc
 ffff8880209a8b00: fa fc fc fc 05 fc fc fc 05 fc fc fc 05 fc fc fc
>ffff8880209a8b80: fa fc fc fc fa fc fc fc 02 fc fc fc fa fc fc fc
                                           ^
 ffff8880209a8c00: 00 fc fc fc 00 fc fc fc 00 fc fc fc 05 fc fc fc
 ffff8880209a8c80: 05 fc fc fc 05 fc fc fc fa fc fc fc 00 fc fc fc
==================================================================

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/04 10:11 upstream fe46a7dd189e 51c4dcff .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
2024/04/04 21:14 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 707081b61156 0ee3535e .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
2024/04/09 03:18 upstream fe46a7dd189e 53df08b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
2024/04/04 09:35 upstream fe46a7dd189e 51c4dcff .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
2024/04/08 21:18 linux-next 11cb68ad52ac 53df08b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
2024/04/18 19:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci b5d2afe8745b af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
2024/04/18 19:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci b5d2afe8745b af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
2024/04/18 19:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci b5d2afe8745b af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-out-of-bounds Read in rfcomm_sock_setsockopt
* Struck through repros no longer work on HEAD.