KASAN: vmalloc-out-of-bounds Read in bpf_trace

KASAN: vmalloc-out-of-bounds Read in bpf_trace_run5
Status: upstream: reported C repro on 2020/09/24 09:26
Reported-by: syzbot+856297c51366950e115e@syzkaller.appspotmail.com
First crash: 34d, last: 34d

Cause bisection: introduced by (bisect log) :
commit 1e6d690b9334b7e1b31d25fd8d93e980e449a5f9
Author: Song Liu <songliubraving@fb.com>
Date: Thu Nov 17 23:24:39 2016 +0000

md/r5cache: caching phase of r5cache

Crash: UBSAN: undefined-behaviour in batadv_iv_ogm_queue_add (log)
Repro: C syz .config

Sample crash report:

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in __bpf_trace_run kernel/trace/bpf_trace.c:1937 [inline]
BUG: KASAN: vmalloc-out-of-bounds in bpf_trace_run5+0x401/0x410 kernel/trace/bpf_trace.c:1977
Read of size 8 at addr ffffc90000e80030 by task rs:main Q:Reg/6567

CPU: 1 PID: 6567 Comm: rs:main Q:Reg Not tainted 5.9.0-rc5-next-20200921-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+0x198/0x1fb lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x497 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 __bpf_trace_run kernel/trace/bpf_trace.c:1937 [inline]
 bpf_trace_run5+0x401/0x410 kernel/trace/bpf_trace.c:1977
 __bpf_trace_ext4_journal_start+0x142/0x180 include/trace/events/ext4.h:1788
 __traceiter_ext4_journal_start+0x83/0xd0 include/trace/events/ext4.h:1788
 trace_ext4_journal_start include/trace/events/ext4.h:1788 [inline]
 __ext4_journal_start_sb+0x228/0x440 fs/ext4/ext4_jbd2.c:96
 __ext4_journal_start fs/ext4/ext4_jbd2.h:328 [inline]
 ext4_dirty_inode+0xbc/0x130 fs/ext4/inode.c:5850
 __mark_inode_dirty+0x888/0x1190 fs/fs-writeback.c:2260
 generic_update_time+0x21c/0x370 fs/inode.c:1764
 update_time fs/inode.c:1777 [inline]
 file_update_time+0x434/0x520 fs/inode.c:1992
 file_modified fs/inode.c:2015 [inline]
 file_modified+0x7d/0xa0 fs/inode.c:2000
 ext4_write_checks fs/ext4/file.c:248 [inline]
 ext4_buffered_write_iter+0xf9/0x4a0 fs/ext4/file.c:264
 ext4_file_write_iter+0x1f3/0x13e0 fs/ext4/file.c:660
 call_write_iter include/linux/fs.h:1895 [inline]
 new_sync_write+0x426/0x650 fs/read_write.c:517
 vfs_write+0x57d/0x700 fs/read_write.c:595
 ksys_write+0x12d/0x250 fs/read_write.c:648
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fed08e3a1cd
Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fed063f5590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fecfc0238a0 RCX: 00007fed08e3a1cd
RDX: 0000000000000dd6 RSI: 00007fecfc0238a0 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007fecfc023620
R13: 00007fed063f55b0 R14: 0000560a2b025360 R15: 0000000000000dd6


Memory state around the buggy address:
 ffffc90000e7ff00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90000e7ff80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90000e80000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                                     ^
 ffffc90000e80080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90000e80100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Maintainers
ci-upstream-linux-next-kasan-gce-root	2020/09/22 10:05	linux-next	b10b8ad8	9e1fa68e	.config	log	report	syz	C		andriin@fb.com, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, john.fastabend@gmail.com, kafai@fb.com, kpsingh@chromium.org, kuba@kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, netdev@vger.kernel.org, rostedt@goodmis.org, songliubraving@fb.com, yhs@fb.com
ci-upstream-linux-next-kasan-gce-root	2020/09/22 09:45	linux-next	b10b8ad8	9e1fa68e	.config	log	report			info	andriin@fb.com, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, john.fastabend@gmail.com, kafai@fb.com, kpsingh@chromium.org, kuba@kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, netdev@vger.kernel.org, rostedt@goodmis.org, songliubraving@fb.com, yhs@fb.com