syzbot


KASAN: global-out-of-bounds Read in ax25_hard_header

Status: auto-closed as invalid on 2022/01/31 09:56
Subsystems: hams
[Documentation on labels]
First crash: 877d, last: 877d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: global-out-of-bounds Read in ax25_hard_header (2) hams 1 532d 532d 0/26 auto-obsoleted due to no activity on 2023/01/14 10:14

Sample crash report:
==================================================================
BUG: KASAN: global-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: global-out-of-bounds in ax25_hard_header net/ax25/ax25_ip.c:60 [inline]
BUG: KASAN: global-out-of-bounds in ax25_hard_header+0xc5/0x370 net/ax25/ax25_ip.c:45
Read of size 7 at addr ffffffff8a173b40 by task dhcpcd/3315

CPU: 1 PID: 3315 Comm: dhcpcd Not tainted 5.15.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xf/0x309 mm/kasan/report.c:256
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 memcpy+0x20/0x60 mm/kasan/shadow.c:65
 memcpy include/linux/fortify-string.h:191 [inline]
 ax25_hard_header net/ax25/ax25_ip.c:60 [inline]
 ax25_hard_header+0xc5/0x370 net/ax25/ax25_ip.c:45
 dev_hard_header include/linux/netdevice.h:3264 [inline]
 vlan_dev_hard_header+0x13d/0x510 net/8021q/vlan_dev.c:82
 dev_hard_header include/linux/netdevice.h:3264 [inline]
 lapbeth_data_transmit+0x29f/0x350 drivers/net/wan/lapbether.c:257
 lapb_data_transmit+0x8f/0xc0 net/lapb/lapb_iface.c:447
 lapb_transmit_buffer+0x183/0x390 net/lapb/lapb_out.c:149
 lapb_send_control+0x1c7/0x370 net/lapb/lapb_subr.c:251
 lapb_establish_data_link+0xe7/0x110 net/lapb/lapb_out.c:163
 lapb_device_event+0x395/0x560 net/lapb/lapb_iface.c:512
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1996
 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline]
 call_netdevice_notifiers net/core/dev.c:2022 [inline]
 __dev_notify_flags+0x110/0x2b0 net/core/dev.c:8806
 dev_change_flags+0x112/0x170 net/core/dev.c:8844
 devinet_ioctl+0x15d1/0x1ca0 net/ipv4/devinet.c:1142
 inet_ioctl+0x1e6/0x320 net/ipv4/af_inet.c:971
 sock_do_ioctl+0xcc/0x230 net/socket.c:1118
 sock_ioctl+0x2f1/0x640 net/socket.c:1235
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f2bd742e0e7
Code: 3c 1c e8 1c ff ff ff 85 c0 79 87 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 61 9d 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffed4103c18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2bd73406c8 RCX: 00007f2bd742e0e7
RDX: 00007ffed4113e08 RSI: 0000000000008914 RDI: 0000000000000087
RBP: 00007ffed4123fb8 R08: 00007ffed4113dc8 R09: 00007ffed4113d78
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffed4113e08 R14: 0000000000000028 R15: 0000000000008914

The buggy address belongs to the variable:
 bcast_addr+0x0/0x1460

Memory state around the buggy address:
 ffffffff8a173a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff8a173a80: 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 00 00 00 00
>ffffffff8a173b00: 00 00 f9 f9 f9 f9 f9 f9 06 f9 f9 f9 f9 f9 f9 f9
                                           ^
 ffffffff8a173b80: 00 00 00 00 00 06 f9 f9 f9 f9 f9 f9 03 f9 f9 f9
 ffffffff8a173c00: f9 f9 f9 f9 00 00 00 00 00 f9 f9 f9 f9 f9 f9 f9
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/11/02 09:51 upstream e66435936756 098b5d53 .config console log report info ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in ax25_hard_header
* Struck through repros no longer work on HEAD.