bisecting fixing commit since ae83d0b416db002fe95601e7f97f64b59514d936
building syzkaller on 347a5dc3c7886bfe3ce784eabc5ee30100f13e0a
testing commit ae83d0b416db002fe95601e7f97f64b59514d936 with gcc (GCC) 8.4.1 20210217
kernel signature: c422004db97986cd892a5574b1ab2296f3b21f278e120b8217303abcae7b9e7a
all runs: crashed: WARNING in kcm_write_msgs
testing current HEAD 7a7fd0de4a9804299793e564a555a49c1fc924cb
testing commit 7a7fd0de4a9804299793e564a555a49c1fc924cb with gcc (GCC) 10.2.1 20210217
kernel signature: 201ffe122fb49a9b3100e11fe31dff1668293430b7bb4a48f241323a9b69a298
all runs: crashed: WARNING in kcm_write_msgs
revisions tested: 2, total time: 23m4.298501143s (build: 12m20.813962166s, test: 10m0.87121673s)
the crash still happens on HEAD
commit msg: Merge branch 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
crash: WARNING in kcm_write_msgs
------------[ cut here ]------------
WARNING: CPU: 1 PID: 12154 at net/kcm/kcmsock.c:628 kcm_write_msgs+0xeb2/0x1730 net/kcm/kcmsock.c:661
Modules linked in:
CPU: 1 PID: 12154 Comm: syz-executor.4 Not tainted 5.12.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kcm_write_msgs+0xeb2/0x1730 net/kcm/kcmsock.c:628
Code: 04 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 6a 07 00 00 48 8b 44 24 58 45 31 c0 4c 89 70 10 e9 4c f5 ff ff <0f> 0b 41 b8 ea ff ff ff e9 3f f5 ff ff 0f 0b e9 e9 f6 ff ff 8b 44
RSP: 0018:ffffc900008479c8 EFLAGS: 00010246
RAX: ffff888103910000 RBX: ffff8881039100c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffed1023894677 RDI: ffff8881039100c2
RBP: 00000000000000c0 R08: 0000000000008000 R09: 0000000000000000
R10: fffffbfff17f5191 R11: 0000000000000000 R12: ffff88811c4a3200
R13: ffff888121584500 R14: ffff888119e7dbc0 R15: 0000000000008000
FS:  00007fdb238b3700(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000052a058 CR3: 000000010f0e9003 CR4: 00000000001706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kcm_sendmsg+0x1234/0x2380 net/kcm/kcmsock.c:1034
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xab/0xe0 net/socket.c:674
 sock_write_iter+0x211/0x370 net/socket.c:1001
 call_write_iter include/linux/fs.h:1977 [inline]
 new_sync_write+0x4ad/0x5f0 fs/read_write.c:518
 vfs_write+0x5c3/0x870 fs/read_write.c:605
 ksys_write+0x171/0x1d0 fs/read_write.c:658
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x464149
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:00007fdb238b3198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464149
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000522da0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00
R13: 00007fdb238b36bc R14: 00000000ffffffff R15: 0000000000000003