syzbot


KASAN: out-of-bounds Write in tls_push_record

Status: fixed on 2019/02/26 22:09
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+43358359519ad16cf05e@syzkaller.appspotmail.com
Fix commit: d829e9c4112b tls: convert to generic sk_msg interface
First crash: 2059d, last: 1958d
Duplicate bugs (2)
duplicates (2):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
KASAN: slab-out-of-bounds Write in tls_push_record (2) net 8 1958d 2033d 0/26 closed as dup on 2019/02/20 15:54
KASAN: slab-out-of-bounds Read in tls_push_record net 1 1981d 1979d 0/26 closed as dup on 2019/02/20 16:55
Discussions (1)
Title Replies (including bot) Last reply
KASAN: out-of-bounds Write in tls_push_record 1 (2) 2019/02/26 07:59
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: use-after-free Write in tls_push_record C error 120 387d 1771d 0/1 upstream: reported C repro on 2019/04/21 15:31
linux-4.19 KASAN: out-of-bounds Write in tls_push_record 4 1652d 1712d 0/1 auto-closed as invalid on 2019/12/16 22:08
linux-4.19 KASAN: out-of-bounds Write in tls_push_record (2) 3 1350d 1503d 0/1 auto-closed as invalid on 2020/10/14 06:11

Sample crash report:
RDX: 00000000fffffdef RSI: 00000000200005c0 RDI: 0000000000000004
RBP: 00000000006cb018 R08: 0000000020000000 R09: 000000000000001c
R10: 0000000000000040 R11: 0000000000000216 R12: 0000000000000005
R13: ffffffffffffffff R14: 0000000000000000 R15: 0000000000000000
==================================================================
BUG: KASAN: out-of-bounds in tls_fill_prepend include/net/tls.h:339 [inline]
BUG: KASAN: out-of-bounds in tls_push_record+0x1091/0x1400 net/tls/tls_sw.c:239
Write of size 1 at addr ffff8801c07b8000 by task syz-executor985/4467

CPU: 0 PID: 4467 Comm: syz-executor985 Not tainted 4.18.0-rc3-next-20180706+ #1
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+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 __asan_report_store1_noabort+0x17/0x20 mm/kasan/report.c:435
 tls_fill_prepend include/net/tls.h:339 [inline]
 tls_push_record+0x1091/0x1400 net/tls/tls_sw.c:239
 tls_sw_push_pending_record+0x22/0x30 net/tls/tls_sw.c:276
 tls_handle_open_record net/tls/tls_main.c:164 [inline]
 tls_sk_proto_close+0x74c/0xae0 net/tls/tls_main.c:264
 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427
 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:459
 __sock_release+0xd7/0x260 net/socket.c:600
 sock_close+0x19/0x20 net/socket.c:1151
 __fput+0x35d/0x930 fs/file_table.c:215
 ____fput+0x15/0x20 fs/file_table.c:251
 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x1b08/0x2750 kernel/exit.c:869
 do_group_exit+0x177/0x440 kernel/exit.c:972
 __do_sys_exit_group kernel/exit.c:983 [inline]
 __se_sys_exit_group kernel/exit.c:981 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:981
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43f358
Code: Bad RIP value.
RSP: 002b:00007ffd4c2414b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f358
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004bf448 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea000701ee00 count:0 mapcount:-128 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 ffffea0006b7be08 ffff88021fffac18 0000000000000000
raw: 0000000000000000 0000000000000003 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c07b7f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c07b7f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8801c07b8000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff8801c07b8080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c07b8100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/07/07 18:04 linux-next 526674536360 ab89aea9 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2018/10/13 14:18 upstream bab5c80b2110 caf12900 .config console log report ci-upstream-kasan-gce-root
2018/10/07 14:14 upstream fb1c592cf4c9 8b311eaf .config console log report ci-upstream-kasan-gce
2018/09/24 17:41 upstream 02214bfc89c7 2f485cdf .config console log report ci-upstream-kasan-gce
2018/08/19 03:35 upstream a18d783fedfe de20bcbb .config console log report ci-upstream-kasan-gce
2018/10/16 19:59 net-old bd8be2cf8b69 1ba7fd7e .config console log report ci-upstream-net-this-kasan-gce
2018/09/11 17:38 net-old 7c5cca358854 4ae17b1f .config console log report ci-upstream-net-this-kasan-gce
2018/08/18 05:01 net-old bfdd19ad80f2 db1858f6 .config console log report ci-upstream-net-this-kasan-gce
2018/10/13 13:51 net-next-old a688c53a0277 caf12900 .config console log report ci-upstream-net-kasan-gce
2018/07/25 03:04 linux-next 3946cd385042 375a3e31 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.