bisecting fixing commit since c10b57a567e4333b9fdf60b5ec36de9859263ca2
building syzkaller on 435c6d538899a51dde5bbc2472cd4e7ecb2ef270
testing commit c10b57a567e4333b9fdf60b5ec36de9859263ca2 with gcc (GCC) 8.1.0
kernel signature: 3995c36143c50eaa69d39d12516d0e128fad18b27760f05f324b8c690fa005de
all runs: crashed: WARNING in rds_message_alloc_sgs
testing current HEAD a41ba30d9df20fe141c92aacbb56b6b077f19716
testing commit a41ba30d9df20fe141c92aacbb56b6b077f19716 with gcc (GCC) 8.1.0
kernel signature: 2ffdd81afff685c658d6e238245fcd5f66a1ccc03db548b2e69de91a31a24acc
all runs: crashed: WARNING in rds_message_alloc_sgs
revisions tested: 2, total time: 24m38.876120459s (build: 16m14.367976493s, test: 7m19.913312002s)
the crash still happens on HEAD
commit msg: Linux 4.14.181
crash: WARNING in rds_message_alloc_sgs
------------[ cut here ]------------
WARNING: CPU: 1 PID: 29278 at net/rds/message.c:227 rds_message_alloc_sgs+0xcc/0x110 net/rds/message.c:238
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 29278 Comm: syz-executor.2 Not tainted 4.14.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.8+0x25/0x2c kernel/panic.c:547
 report_bug+0x1a4/0x1f3 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:rds_message_alloc_sgs+0xcc/0x110 net/rds/message.c:227
RSP: 0018:ffff88806d927798 EFLAGS: 00010212
RAX: 0000000000000009 RBX: ffff888087e3a040 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000017 RDI: ffff888087e3a1b4
RBP: ffff88806d9277c0 R08: ffff88806d9274e8 R09: ffff88809142b480
R10: ffff888087e3a040 R11: 000000001749a5fd R12: 0000000000000000
R13: 0000000000000017 R14: ffff888087e3a1b0 R15: 0000000000000017
 rds_cmsg_rdma_args+0x62a/0x15c0 net/rds/rdma.c:621
 rds_cmsg_send net/rds/send.c:943 [inline]
 rds_sendmsg+0xcad/0x2210 net/rds/send.c:1132
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0xf0 net/socket.c:656
 ___sys_sendmsg+0x625/0x920 net/socket.c:2062
 __sys_sendmsg+0xc1/0x140 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0xd/0x20 net/socket.c:2103
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45c889
RSP: 002b:00007fb5e5cd7c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb5e5cd86d4 RCX: 000000000045c889
RDX: 0000000000000000 RSI: 0000000020001600 RDI: 0000000000000003
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a01 R14: 00000000004ccbdc R15: 000000000076bf0c
Kernel Offset: disabled
Rebooting in 86400 seconds..