* [syzbot] BUG: corrupted list in p9_fd_cancel (2) @ 2022-10-23 10:41 syzbot 2022-10-23 16:09 ` Christian Schoenebeck 0 siblings, 1 reply; 2+ messages in thread From: syzbot @ 2022-10-23 10:41 UTC (permalink / raw) To: asmadeus, davem, edumazet, ericvh, kuba, linux-kernel, linux_oss, lucho, netdev, pabeni, syzkaller-bugs, v9fs-developer Hello, syzbot found the following issue on: HEAD commit: d47136c28015 Merge tag 'hwmon-for-v6.1-rc2' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12f36de2880000 kernel config: https://syzkaller.appspot.com/x/.config?x=4789759e8a6d5f57 dashboard link: https://syzkaller.appspot.com/bug?extid=9b69b8d10ab4a7d88056 compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1076cb7c880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=102eabd2880000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/5664e231e97f/disk-d47136c2.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/9bbe0daa4a04/vmlinux-d47136c2.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9b69b8d10ab4a7d88056@syzkaller.appspotmail.com list_del corruption, ffff88802295c4b0->next is LIST_POISON1 (dead000000000100) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:55! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 4018 Comm: syz-executor365 Not tainted 6.1.0-rc1-syzkaller-00427-gd47136c28015 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:__list_del_entry_valid+0xef/0x130 lib/list_debug.c:53 Code: 29 40 03 06 0f 0b 48 c7 c7 e0 bf 0a 8b 4c 89 fe 31 c0 e8 16 40 03 06 0f 0b 48 c7 c7 40 c0 0a 8b 4c 89 fe 31 c0 e8 03 40 03 06 <0f> 0b 48 c7 c7 a0 c0 0a 8b 4c 89 fe 31 c0 e8 f0 3f 03 06 0f 0b 48 RSP: 0018:ffffc900044c7630 EFLAGS: 00010246 RAX: 000000000000004e RBX: dead000000000122 RCX: 5051969350135b00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff816cec5d R09: fffff52000898e7d R10: fffff52000898e7d R11: 1ffff92000898e7c R12: dffffc0000000000 R13: 1ffff1100452b880 R14: dead000000000100 R15: ffff88802295c4b0 FS: 00007f0d52859700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001000 CR3: 000000007ed87000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __list_del_entry include/linux/list.h:134 [inline] list_del include/linux/list.h:148 [inline] p9_fd_cancel+0x9c/0x230 net/9p/trans_fd.c:703 p9_client_rpc+0x92c/0xad0 net/9p/client.c:723 p9_client_create+0x997/0x1030 net/9p/client.c:1015 v9fs_session_init+0x1e3/0x1990 fs/9p/v9fs.c:408 v9fs_mount+0xd2/0xcb0 fs/9p/vfs_super.c:126 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x289/0xad0 fs/namespace.c:3040 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0d528a89f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0d528592f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f0d529344e0 RCX: 00007f0d528a89f9 RDX: 0000000020000040 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 00007f0d52901174 R08: 0000000020000080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 0000000000000004 R14: 64663d736e617274 R15: 00007f0d529344e8 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_del_entry_valid+0xef/0x130 lib/list_debug.c:53 Code: 29 40 03 06 0f 0b 48 c7 c7 e0 bf 0a 8b 4c 89 fe 31 c0 e8 16 40 03 06 0f 0b 48 c7 c7 40 c0 0a 8b 4c 89 fe 31 c0 e8 03 40 03 06 <0f> 0b 48 c7 c7 a0 c0 0a 8b 4c 89 fe 31 c0 e8 f0 3f 03 06 0f 0b 48 RSP: 0018:ffffc900044c7630 EFLAGS: 00010246 RAX: 000000000000004e RBX: dead000000000122 RCX: 5051969350135b00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff816cec5d R09: fffff52000898e7d R10: fffff52000898e7d R11: 1ffff92000898e7c R12: dffffc0000000000 R13: 1ffff1100452b880 R14: dead000000000100 R15: ffff88802295c4b0 FS: 00007f0d52859700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001000 CR3: 000000007ed87000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This report 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@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] BUG: corrupted list in p9_fd_cancel (2) 2022-10-23 10:41 [syzbot] BUG: corrupted list in p9_fd_cancel (2) syzbot @ 2022-10-23 16:09 ` Christian Schoenebeck 0 siblings, 0 replies; 2+ messages in thread From: Christian Schoenebeck @ 2022-10-23 16:09 UTC (permalink / raw) To: asmadeus, davem, edumazet, ericvh, kuba, linux-kernel, lucho, netdev, pabeni, syzkaller-bugs, v9fs-developer, syzbot On Sunday, October 23, 2022 12:41:34 PM CEST syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: d47136c28015 Merge tag 'hwmon-for-v6.1-rc2' of git://git.k.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=12f36de2880000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4789759e8a6d5f57 > dashboard link: https://syzkaller.appspot.com/bug?extid=9b69b8d10ab4a7d88056 > compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1076cb7c880000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=102eabd2880000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/5664e231e97f/disk-d47136c2.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/9bbe0daa4a04/vmlinux-d47136c2.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9b69b8d10ab4a7d88056@syzkaller.appspotmail.com > > list_del corruption, ffff88802295c4b0->next is LIST_POISON1 (dead000000000100) > ------------[ cut here ]------------ > kernel BUG at lib/list_debug.c:55! [...] > Call Trace: > <TASK> > __list_del_entry include/linux/list.h:134 [inline] > list_del include/linux/list.h:148 [inline] > p9_fd_cancel+0x9c/0x230 net/9p/trans_fd.c:703 I only had a short cycle on this yet: so the problem is that the req_list list head is removed twice, which triggers this warning from [lib/list_debug.c]. Probably moving spin_unlock() call back down to the end of function p9_conn_cancel() might fix this: diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index 56a186768750..409f0da70c52 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -207,8 +207,6 @@ static void p9_conn_cancel(struct p9_conn *m, int err) list_move(&req->req_list, &cancel_list); } - spin_unlock(&m->req_lock); - list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); list_del(&req->req_list); @@ -216,6 +214,8 @@ static void p9_conn_cancel(struct p9_conn *m, int err) req->t_err = err; p9_client_cb(m->client, req, REQ_STATUS_ERROR); } + + spin_unlock(&m->req_lock); } static __poll_t spin_unlock() was recently moved up a bit to fix a dead lock, however that dead lock happened with a lock on client level, meanwhile it was converted into a lock on connection level. The question is whether that would fix this for good and not just move it, because there are a bunch of list removal calls that don't check for the request state or something to prevent a double removal at other places. Best regards, Christian Schoenebeck ^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2022-10-23 16:10 UTC | newest] Thread overview: 2+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2022-10-23 10:41 [syzbot] BUG: corrupted list in p9_fd_cancel (2) syzbot 2022-10-23 16:09 ` Christian Schoenebeck
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).