KASAN: out-of-bounds Read in unwind_next_frame (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 57ac921e Merge 4.14.138 into android-4.14
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=170318a6600000
kernel config: https://syzkaller.appspot.com/x/.config?x=2ac71e39ec484d3c
dashboard link: https://syzkaller.appspot.com/bug?extid=0ea21dd409dff347ee4b
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0ea21d...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: out-of-bounds in unwind_next_frame+0x169f/0x1810
arch/x86/kernel/unwind_orc.c:470
Read of size 8 at addr ffff8881a3b27e78 by task syz-executor.0/21505

CPU: 0 PID: 21505 Comm: syz-executor.0 Not tainted 4.14.138+ #30
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xca/0x134 lib/dump_stack.c:53
print_address_description+0x60/0x226 mm/kasan/report.c:187
__kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316
unwind_next_frame+0x169f/0x1810 arch/x86/kernel/unwind_orc.c:470
__save_stack_trace+0x7a/0xf0 arch/x86/kernel/stacktrace.c:44
save_stack_trace_tsk arch/x86/kernel/stacktrace.c:73 [inline]
save_stack_trace_tsk+0x34/0x40 arch/x86/kernel/stacktrace.c:68
proc_pid_stack+0x194/0x270 fs/proc/base.c:460
proc_single_show+0xf1/0x160 fs/proc/base.c:762
seq_read+0x4f7/0x1180 fs/seq_file.c:237
do_loop_readv_writev fs/read_write.c:699 [inline]
do_loop_readv_writev fs/read_write.c:686 [inline]
do_iter_read+0x3e8/0x5b0 fs/read_write.c:923
vfs_readv+0xe6/0x150 fs/read_write.c:985
do_preadv+0x189/0x230 fs/read_write.c:1069
do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459829
RSP: 002b:00007f15b2a58c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459829
RDX: 10000000000002a1 RSI: 0000000020000480 RDI: 0000000000000004
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f15b2a596d4
R13: 00000000004c6b38 R14: 00000000004dbcc8 R15: 00000000ffffffff

The buggy address belongs to the page:
page:ffffea00068ec9c0 count:0 mapcount:0 mapping: (null) index:0x0
flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8881a3b27d00: 00 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00
ffff8881a3b27d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff8881a3b27e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff8881a3b27e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881a3b27f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 59eb65b2 ANDROID: virtio: virtio_input: Set the amount of ..
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=14f51a24e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=6473d91fae805c22

dashboard link: https://syzkaller.appspot.com/bug?extid=0ea21dd409dff347ee4b
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12bc6be4e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=159e33e4e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0ea21d...@syzkaller.appspotmail.com

==================================================================

BUG: KASAN: out-of-bounds in deref_stack_regs
arch/x86/kernel/unwind_orc.c:307 [inline]
BUG: KASAN: out-of-bounds in unwind_next_frame+0x17a5/0x1810
arch/x86/kernel/unwind_orc.c:437
Read of size 8 at addr ffff8881cef0fed8 by task syz-executor381/10127

CPU: 0 PID: 10127 Comm: syz-executor381 Not tainted 4.14.150+ #0

Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xca/0x134 lib/dump_stack.c:53
print_address_description+0x60/0x226 mm/kasan/report.c:187
__kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316

deref_stack_regs arch/x86/kernel/unwind_orc.c:307 [inline]
unwind_next_frame+0x17a5/0x1810 arch/x86/kernel/unwind_orc.c:437

__save_stack_trace+0x7a/0xf0 arch/x86/kernel/stacktrace.c:44
save_stack_trace_tsk arch/x86/kernel/stacktrace.c:73 [inline]
save_stack_trace_tsk+0x34/0x40 arch/x86/kernel/stacktrace.c:68
proc_pid_stack+0x194/0x270 fs/proc/base.c:460
proc_single_show+0xf1/0x160 fs/proc/base.c:762
seq_read+0x4f7/0x1180 fs/seq_file.c:237
do_loop_readv_writev fs/read_write.c:699 [inline]
do_loop_readv_writev fs/read_write.c:686 [inline]
do_iter_read+0x3e8/0x5b0 fs/read_write.c:923
vfs_readv+0xe6/0x150 fs/read_write.c:985
do_preadv+0x189/0x230 fs/read_write.c:1069
do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7

RIP: 0033:0x446af9
RSP: 002b:00007f3971e0ed18 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000006dbc78 RCX: 0000000000446af9
RDX: 10000000000002a1 RSI: 0000000020000480 RDI: 0000000000000006
RBP: 00000000006dbc70 R08: 00007f3971e0f700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc7c
R13: 00007f3971e0ed20 R14: 00007f3971e0ed20 R15: 0000000000000001

The buggy address belongs to the page:

page:ffffea00073bc3c0 count:0 mapcount:0 mapping: (null) index:0x0

flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8881cef0fd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1
ffff8881cef0fe00: f1 00 f2 f2 f2 00 f2 f2 f2 00 00 f3 f3 00 00 00
> ffff8881cef0fe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff8881cef0ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881cef0ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================