syzbot


general protection fault in proc_kill_sb

Status: fixed on 2020/07/17 17:58
Reported-by: syzbot+4abac52934a48af5ff19@syzkaller.appspotmail.com
Fix commit: 058f2e4da79b proc: s_fs_info may be NULL when proc_kill_sb is called
First crash: 795d, last: 780d

Sample crash report:
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00000000000000d4 R14: 00000000004d1f38 R15: 00007f983cf3b6d4
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 29300 Comm: syz-executor.5 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:proc_kill_sb+0x4d/0x110 fs/proc/root.c:267
Code: c1 ea 03 80 3c 02 00 0f 85 ad 00 00 00 49 8b ac 24 68 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7d 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a1 00 00 00 4c 8b 6d 08 4d 85 ed 74 0d e8 cb 51
RSP: 0018:ffffc90004c87d60 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc900140b9000
RDX: 0000000000000001 RSI: ffffffff81e37c9d RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff8c347a2f R11: fffffbfff1868f45 R12: ffff888033b58000
R13: 00000000fffffff4 R14: 0000000000000000 R15: ffff888033b58068
FS:  00007f983cf3b700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005635a58b29c0 CR3: 00000000944cc000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 deactivate_locked_super+0x8c/0xf0 fs/super.c:335
 vfs_get_super+0x258/0x2d0 fs/super.c:1212
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 vfs_fsconfig_locked+0x22c/0x3c0 fs/fsopen.c:232
 __do_sys_fsconfig fs/fsopen.c:439 [inline]
 __se_sys_fsconfig fs/fsopen.c:314 [inline]
 __x64_sys_fsconfig+0x621/0x860 fs/fsopen.c:314
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca59
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f983cf3ac78 EFLAGS: 00000246 ORIG_RAX: 00000000000001af
RAX: ffffffffffffffda RBX: 00000000004dc7a0 RCX: 000000000045ca59
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00000000000000d4 R14: 00000000004d1f38 R15: 00007f983cf3b6d4
Modules linked in:
---[ end trace cd1dd8ce4dfb95c8 ]---
RIP: 0010:proc_kill_sb+0x4d/0x110 fs/proc/root.c:267
Code: c1 ea 03 80 3c 02 00 0f 85 ad 00 00 00 49 8b ac 24 68 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7d 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a1 00 00 00 4c 8b 6d 08 4d 85 ed 74 0d e8 cb 51
RSP: 0018:ffffc90004c87d60 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc900140b9000
RDX: 0000000000000001 RSI: ffffffff81e37c9d RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff8c347a2f R11: fffffbfff1868f45 R12: ffff888033b58000
R13: 00000000fffffff4 R14: 0000000000000000 R15: ffff888033b58068
FS:  00007f983cf3b700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000401ca0 CR3: 00000000944cc000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (8):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2020/06/22 03:41 upstream 7ae77150d94d 4f2acff9 .config log report
ci-upstream-kasan-gce 2020/06/20 07:05 upstream 7ae77150d94d 81abc331 .config log report
ci-upstream-kasan-gce 2020/06/19 23:34 upstream 7ae77150d94d 81abc331 .config log report
ci-upstream-kasan-gce 2020/06/19 21:03 upstream 7ae77150d94d 81abc331 .config log report
ci-upstream-kasan-gce 2020/06/18 07:19 upstream 7ae77150d94d d45a4d69 .config log report
ci-upstream-kasan-gce 2020/06/11 21:55 upstream 7ae77150d94d 3ab7a05a .config log report
ci-upstream-kasan-gce 2020/06/06 10:05 upstream 7ae77150d94d e6b89e4e .config log report
ci-upstream-kasan-gce-386 2020/06/18 17:36 upstream 7ae77150d94d d45a4d69 .config log report