syzbot


KASAN: invalid-free in sctp_stream_free

Status: fixed on 2019/03/06 07:43
Subsystems: sctp
[Documentation on labels]
Reported-by: syzbot+58e480e7b28f2d890bfd@syzkaller.appspotmail.com
Fix commit: af98c5a78517 sctp: set stream ext to NULL after freeing it in sctp_stream_outq_migrate
First crash: 1967d, last: 1958d
Discussions (4)
Title Replies (including bot) Last reply
[PATCH 4.20 000/183] 4.20.13-stable review 198 (198) 2019/02/27 09:05
[PATCH 4.19 000/152] 4.19.26-stable review 157 (157) 2019/02/26 17:47
[PATCH net] sctp: set stream ext to NULL after freeing it in sctp_stream_outq_migrate 4 (4) 2019/02/14 00:34
KASAN: invalid-free in sctp_stream_free 1 (2) 2019/02/10 14:36

Sample crash report:
==================================================================
BUG: KASAN: double-free or invalid-free in sctp_stream_free+0xfa/0x190 net/sctp/stream.c:187

CPU: 0 PID: 7775 Comm: syz-executor682 Not tainted 5.0.0-rc4-next-20190201 #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report_invalid_free+0x65/0xa0 mm/kasan/report.c:278
 __kasan_slab_free+0x13a/0x150 mm/kasan/common.c:439
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:468
 __cache_free mm/slab.c:3488 [inline]
 kfree+0xcf/0x230 mm/slab.c:3807
 sctp_stream_free+0xfa/0x190 net/sctp/stream.c:187
 sctp_association_free+0x235/0x79a net/sctp/associola.c:373
 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:939 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1353 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline]
 sctp_do_sm+0x3c4e/0x5380 net/sctp/sm_sideeffect.c:1191
 sctp_assoc_bh_rcv+0x343/0x660 net/sctp/associola.c:1074
 sctp_inq_push+0x1ea/0x290 net/sctp/inqueue.c:95
 sctp_backlog_rcv+0x196/0xbe0 net/sctp/input.c:354
 sk_backlog_rcv include/net/sock.h:936 [inline]
 __release_sock+0x12e/0x3a0 net/core/sock.c:2309
 release_sock+0x59/0x1c0 net/core/sock.c:2825
 sctp_close+0x4a4/0x860 net/sctp/socket.c:1550
 inet_release+0x105/0x1f0 net/ipv4/af_inet.c:428
 __sock_release+0xd3/0x250 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1139
 __fput+0x2df/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x90a/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:980
 __do_sys_exit_group kernel/exit.c:991 [inline]
 __se_sys_exit_group kernel/exit.c:989 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:989
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43edd8
Code: Bad RIP value.
RSP: 002b:00007fff92021088 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043edd8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004be688 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000000000000010 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 7775:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_kmalloc mm/kasan/common.c:498 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:471
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:506
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3610
 kmalloc include/linux/slab.h:548 [inline]
 kzalloc include/linux/slab.h:743 [inline]
 sctp_stream_init_ext+0x51/0x110 net/sctp/stream.c:172
 sctp_sendmsg_to_asoc+0x1273/0x17b0 net/sctp/socket.c:1896
 sctp_sendmsg+0x81f/0x17f0 net/sctp/socket.c:2113
 inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 ___sys_sendmsg+0x806/0x930 net/socket.c:2114
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2152
 __do_sys_sendmsg net/socket.c:2161 [inline]
 __se_sys_sendmsg net/socket.c:2159 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7775:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:460
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:468
 __cache_free mm/slab.c:3488 [inline]
 kfree+0xcf/0x230 mm/slab.c:3807
 sctp_stream_outq_migrate+0x3e6/0x540 net/sctp/stream.c:88
 sctp_stream_init+0xbc/0x410 net/sctp/stream.c:139
 sctp_process_init+0x21c3/0x2b20 net/sctp/sm_make_chunk.c:2466
 sctp_cmd_process_init net/sctp/sm_sideeffect.c:682 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1410 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline]
 sctp_do_sm+0x3145/0x5380 net/sctp/sm_sideeffect.c:1191
 sctp_assoc_bh_rcv+0x343/0x660 net/sctp/associola.c:1074
 sctp_inq_push+0x1ea/0x290 net/sctp/inqueue.c:95
 sctp_backlog_rcv+0x196/0xbe0 net/sctp/input.c:354
 sk_backlog_rcv include/net/sock.h:936 [inline]
 __release_sock+0x12e/0x3a0 net/core/sock.c:2309
 release_sock+0x59/0x1c0 net/core/sock.c:2825
 sctp_wait_for_connect+0x316/0x540 net/sctp/socket.c:8998
 sctp_sendmsg_to_asoc+0x13e3/0x17b0 net/sctp/socket.c:1967
 sctp_sendmsg+0x81f/0x17f0 net/sctp/socket.c:2113
 inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 ___sys_sendmsg+0x806/0x930 net/socket.c:2114
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2152
 __do_sys_sendmsg net/socket.c:2161 [inline]
 __se_sys_sendmsg net/socket.c:2159 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a7e2c480
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff8880a7e2c480, ffff8880a7e2c4e0)
The buggy address belongs to the page:
page:ffffea00029f8b00 count:1 mapcount:0 mapping:ffff88812c3f04c0 index:0xffff8880a7e2c300
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00029f9908 ffff88812c3f1438 ffff88812c3f04c0
raw: ffff8880a7e2c300 ffff8880a7e2c000 0000000100000012 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a7e2c380: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff8880a7e2c400: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8880a7e2c480: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff8880a7e2c500: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880a7e2c580: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/02/04 00:35 linux-next dc4c89997735 c198d5dd .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2019/02/12 05:17 linux-next d4104460aec1 65a0d619 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/02/12 05:12 linux-next d4104460aec1 65a0d619 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/02/12 05:04 linux-next d4104460aec1 65a0d619 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/02/04 00:11 linux-next dc4c89997735 c198d5dd .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.