Hello, syzbot found the following crash on: HEAD commit: 63623fd4 Merge tag 'for-linus' of git://git.kernel.org/pub.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11123e65e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=5d2e033af114153f dashboard link: https://syzkaller.appspot.com/bug?extid=2b10b240fbbed30f10fb compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10d3b329e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16291291e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+2b10b240fbbed30f10fb@xxxxxxxxxxxxxxxxxxxxxxxxx list_add corruption. prev->next should be next (ffff8880a96d3470), but was ffffffff89543330. (prev=ffff8880a660a1e0). ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:28! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 9161 Comm: syz-executor219 Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__list_add_valid+0xbb/0xc0 lib/list_debug.c:26 Code: 48 c7 c7 37 e9 f0 88 4c 89 e6 4c 89 f1 31 c0 e8 be 0d bb fd 0f 0b 48 c7 c7 9a e9 f0 88 4c 89 f6 4c 89 e1 31 c0 e8 a8 0d bb fd <0f> 0b 0f 1f 00 55 48 89 e5 41 57 41 56 41 54 53 49 89 fe 49 bc 00 RSP: 0018:ffffc90002217ba8 EFLAGS: 00010246 RAX: 0000000000000075 RBX: ffff8880a96d3478 RCX: 8fbfbd6f3e068e00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90002217bd0 R08: ffffffff81601324 R09: ffffed1015d46618 R10: ffffed1015d46618 R11: 0000000000000000 R12: ffff8880a660a1e0 R13: dffffc0000000000 R14: ffff8880a96d3470 R15: ffff8880a7f691e0 FS: 00007f2670a0f700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f70fb63c000 CR3: 00000000a6af6000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_add include/linux/list.h:67 [inline] list_add_tail include/linux/list.h:100 [inline] _cma_attach_to_dev drivers/infiniband/core/cma.c:471 [inline] cma_listen_on_dev+0x359/0x8e0 drivers/infiniband/core/cma.c:2493 cma_listen_on_all drivers/infiniband/core/cma.c:2514 [inline] rdma_listen+0x43b/0x9a0 drivers/infiniband/core/cma.c:3622 ucma_listen+0x245/0x300 drivers/infiniband/core/ucma.c:1092 ucma_write+0x2da/0x360 drivers/infiniband/core/ucma.c:1684 __vfs_write+0xb8/0x740 fs/read_write.c:494 vfs_write+0x270/0x580 fs/read_write.c:558 ksys_write+0x117/0x220 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:620 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4495e9 Code: e8 8c e7 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 fb 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2670a0eda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000006dec68 RCX: 00000000004495e9 RDX: 0000000000000010 RSI: 0000000020000100 RDI: 0000000000000004 RBP: 00000000006dec60 R08: 00007f2670a0f700 R09: 0000000000000000 R10: 00007f2670a0f700 R11: 0000000000000246 R12: 00000000006dec6c R13: 0000000000000000 R14: 0000000000006f6c R15: 00000000006dec6c Modules linked in: ---[ end trace 4b9dfed7ba7e8985 ]--- RIP: 0010:__list_add_valid+0xbb/0xc0 lib/list_debug.c:26 Code: 48 c7 c7 37 e9 f0 88 4c 89 e6 4c 89 f1 31 c0 e8 be 0d bb fd 0f 0b 48 c7 c7 9a e9 f0 88 4c 89 f6 4c 89 e1 31 c0 e8 a8 0d bb fd <0f> 0b 0f 1f 00 55 48 89 e5 41 57 41 56 41 54 53 49 89 fe 49 bc 00 RSP: 0018:ffffc90002217ba8 EFLAGS: 00010246 RAX: 0000000000000075 RBX: ffff8880a96d3478 RCX: 8fbfbd6f3e068e00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc90002217bd0 R08: ffffffff81601324 R09: ffffed1015d46618 R10: ffffed1015d46618 R11: 0000000000000000 R12: ffff8880a660a1e0 R13: dffffc0000000000 R14: ffff8880a96d3470 R15: ffff8880a7f691e0 FS: 00007f2670a0f700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f70fb63c000 CR3: 00000000a6af6000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches