bisecting fixing commit since ae83d0b416db002fe95601e7f97f64b59514d936
building syzkaller on 347a5dc3c7886bfe3ce784eabc5ee30100f13e0a
testing commit ae83d0b416db002fe95601e7f97f64b59514d936 with gcc (GCC) 8.1.0
kernel signature: 70ab02f6ed1a48eeb1d3c3b53571347f3d61ef8a29b1592d88bce6acc17a4d9a
all runs: crashed: WARNING in kcm_write_msgs
testing current HEAD 2ff90100ace886895e4fbb2850b8d5e49d931ed6
testing commit 2ff90100ace886895e4fbb2850b8d5e49d931ed6 with gcc (GCC) 8.1.0
kernel signature: 5d6fbc0694bc973a9fd706f4c417677fce9896e9d476ebe96068251efdfa37a3
all runs: crashed: WARNING in kcm_write_msgs
revisions tested: 2, total time: 23m25.023691629s (build: 11m0.016700997s, test: 11m44.736439753s)
the crash still happens on HEAD
commit msg: Merge tag 'hwmon-for-v5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
crash: WARNING in kcm_write_msgs
------------[ cut here ]------------
WARNING: CPU: 1 PID: 16129 at net/kcm/kcmsock.c:628 kcm_write_msgs+0x481/0x570 net/kcm/kcmsock.c:661
Modules linked in:
CPU: 1 PID: 16129 Comm: syz-executor772 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kcm_write_msgs+0x481/0x570 net/kcm/kcmsock.c:628
Code: 24 1c 00 00 00 00 e9 4c fe ff ff 48 8b 74 24 30 31 d2 0f b7 44 24 10 44 89 3e 44 89 56 08 89 46 04 4c 89 66 10 e9 ae fc ff ff <0f> 0b ba ea ff ff ff e9 a2 fc ff ff 0f 0b e9 44 fd ff ff 44 89 7c
RSP: 0018:ffffc900002a3cc8 EFLAGS: 00010246
RAX: 00000000000000c0 RBX: ffff888119347a00 RCX: 0000000000000000
RDX: 0000000000008000 RSI: ffff888119347ac0 RDI: 0000000000000000
RBP: ffff888100dc4000 R08: 0000000000000001 R09: ffff88810c11e500
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88810e0e58c0 R14: ffff88810e14ba00 R15: 0000000000220000
FS:  00007f337e734700(0000) GS:ffff888237d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f337e712e78 CR3: 000000010e371001 CR4: 00000000001706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kcm_sendmsg+0x799/0x7e0 net/kcm/kcmsock.c:1034
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0x2b/0x40 net/socket.c:672
 sock_write_iter+0x95/0xf0 net/socket.c:999
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write+0x18e/0x1a0 fs/read_write.c:518
 vfs_write+0x25d/0x390 fs/read_write.c:605
 ksys_write+0xb9/0xd0 fs/read_write.c:658
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4470a9
Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 ab 05 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f337e733d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000006dcc48 RCX: 00000000004470a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00000000006dcc40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc4c
R13: 00000000200003c0 R14: 00000000004af688 R15: 000000000000d4f5