syzbot


KASAN: wild-memory-access Read in sctp_setsockopt

Status: fixed on 2020/09/16 22:51
Subsystems: sctp
[Documentation on labels]
Fix commit: 519a8a6cf91d net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces"
First crash: 1401d, last: 1401d

Sample crash report:
==================================================================
BUG: KASAN: wild-memory-access in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: wild-memory-access in copy_from_sockptr_offset include/linux/sockptr.h:71 [inline]
BUG: KASAN: wild-memory-access in copy_from_sockptr include/linux/sockptr.h:77 [inline]
BUG: KASAN: wild-memory-access in memdup_sockptr include/linux/sockptr.h:95 [inline]
BUG: KASAN: wild-memory-access in sctp_setsockopt+0x293/0x9380 net/sctp/socket.c:4460
Read of size 8 at addr 00000000ffffffff by task syz-executor099/6836

CPU: 1 PID: 6836 Comm: syz-executor099 Not tainted 5.8.0-syzkaller #0
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+0x18f/0x20d lib/dump_stack.c:118
 __kasan_report mm/kasan/report.c:517 [inline]
 kasan_report.cold+0x5/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 memcpy+0x20/0x60 mm/kasan/common.c:105
 memcpy include/linux/string.h:406 [inline]
 copy_from_sockptr_offset include/linux/sockptr.h:71 [inline]
 copy_from_sockptr include/linux/sockptr.h:77 [inline]
 memdup_sockptr include/linux/sockptr.h:95 [inline]
 sctp_setsockopt+0x293/0x9380 net/sctp/socket.c:4460
 __sys_setsockopt+0x2ad/0x6d0 net/socket.c:2138
 __do_sys_setsockopt net/socket.c:2149 [inline]
 __se_sys_setsockopt net/socket.c:2146 [inline]
 __ia32_sys_setsockopt+0xb9/0x150 net/socket.c:2146
 do_syscall_32_irqs_on arch/x86/entry/common.c:84 [inline]
 __do_fast_syscall_32+0x57/0x80 arch/x86/entry/common.c:126
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:149
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7feb569
Code: 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000fffd6e0c EFLAGS: 00000296 ORIG_RAX: 000000000000016e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000084
RDX: 0000000000000013 RSI: 00000000ffffffff RDI: 0000000000000008
RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/08/14 00:34 upstream 990f227371a4 54ce1ed6 .config console log report syz C ci-upstream-kasan-gce-386
2020/08/13 23:14 upstream 990f227371a4 54ce1ed6 .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.