bisecting fixing commit since 234d53d2bb60a9436a6d4d55bef1712613b79014
building syzkaller on d50eb50a564f0774e935b4f77390e3f591b4206d
testing commit 234d53d2bb60a9436a6d4d55bef1712613b79014
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 49fedd85dde441f2a47f243054e4242e40b663e19ce5dd788256fec2d7cfe8ec
all runs: crashed: KASAN: stack-out-of-bounds Read in iov_iter_revert
testing current HEAD ab2d1d40a128f4b8f8857ae3ecd312c79b3ff8a1
testing commit ab2d1d40a128f4b8f8857ae3ecd312c79b3ff8a1
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: a17bc7d25106b4aee423c618493752cae282dcf9ead911b42f4e9036d09dc994
all runs: crashed: KASAN: stack-out-of-bounds Read in iov_iter_revert
revisions tested: 2, total time: 16m2.983610225s (build: 9m32.343674049s, test: 5m54.384697794s)
the crash still happens on HEAD
commit msg: Revert "vsock: each transport cycles only on its own sockets"
crash: KASAN: stack-out-of-bounds Read in iov_iter_revert
==================================================================
BUG: KASAN: stack-out-of-bounds in iov_iter_revert lib/iov_iter.c:1146 [inline]
BUG: KASAN: stack-out-of-bounds in iov_iter_revert+0x736/0x870 lib/iov_iter.c:1091
Read of size 8 at addr ffffc90000a77768 by task syz-executor.3/436

CPU: 1 PID: 436 Comm: syz-executor.3 Not tainted 5.10.108-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_lvl+0x81/0xac lib/dump_stack.c:118
 print_address_description.constprop.0+0x24/0x150 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x82/0xdb mm/kasan/report.c:436
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 iov_iter_revert lib/iov_iter.c:1146 [inline]
 iov_iter_revert+0x736/0x870 lib/iov_iter.c:1091
 io_write+0x367/0xab0 fs/io_uring.c:3629
 io_issue_sqe+0x141/0x4170 fs/io_uring.c:6045
 __io_queue_sqe+0x1e6/0xb60 fs/io_uring.c:6367
 io_queue_sqe+0x5eb/0xfc0 fs/io_uring.c:6433
 io_submit_sqe fs/io_uring.c:6502 [inline]
 io_submit_sqes+0x10cd/0x27a0 fs/io_uring.c:6730
 __do_sys_io_uring_enter+0xe32/0x1780 fs/io_uring.c:9126
 __se_sys_io_uring_enter fs/io_uring.c:9068 [inline]
 __x64_sys_io_uring_enter+0xdc/0x1a0 fs/io_uring.c:9068
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fe320842a39
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe3207b9188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007fe320945f60 RCX: 00007fe320842a39
RDX: 0000000000000000 RSI: 0000000000007cdc RDI: 0000000000000004
RBP: 00007fe32089ce8f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff646e9c5f R14: 00007fe3207b9300 R15: 0000000000022000


addr ffffc90000a77768 is located in stack of task syz-executor.3/436 at offset 152 in frame:
 io_write+0x0/0xab0 include/linux/uio.h:234

this frame has 3 objects:
 [48, 56) 'iovec'
 [80, 120) '__iter'
 [160, 288) 'inline_vecs'

Memory state around the buggy address:
 ffffc90000a77600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90000a77680: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00
>ffffc90000a77700: 00 f2 f2 f2 00 00 00 00 00 f2 f2 f2 f2 f2 00 00
                                                          ^
 ffffc90000a77780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f3 f3
 ffffc90000a77800: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================