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BUG: unable to handle kernel NULL pointer dereference in cipso_v4_sock_setattr

Status: fixed on 2020/04/15 17:19
Subsystems: lsm net
[Documentation on labels]
Reported-by: syzbot+f4dfece964792d80b139@syzkaller.appspotmail.com
Fix commit: dc24f8b4ecd3 mptcp: add dummy icsk_sync_mss()
First crash: 1524d, last: 1510d
Cause bisection: introduced by (bisect log) :
commit 2303f994b3e187091fd08148066688b08f837efc
Author: Peter Krystad <peter.krystad@linux.intel.com>
Date: Wed Jan 22 00:56:17 2020 +0000

  mptcp: Associate MPTCP context with TCP socket

Crash: BUG: unable to handle kernel NULL pointer dereference in cipso_v4_sock_setattr (log)
Repro: C syz .config
  
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH net] mptcp: add dummy icsk_sync_mss() 3 (3) 2020/02/27 04:50
BUG: unable to handle kernel NULL pointer dereference in cipso_v4_sock_setattr 6 (7) 2020/02/25 15:12
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2020/02/25 11:26 0m pabeni@redhat.com patch net-old error OK

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 8e171067 P4D 8e171067 PUD 93fa2067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 8984 Comm: syz-executor066 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffffc900020b7b80 EFLAGS: 00010246
RAX: 1ffff110124ba600 RBX: 0000000000000000 RCX: ffff88809fefa600
RDX: ffff8880994cdb18 RSI: 0000000000000000 RDI: ffff8880925d3140
RBP: ffffc900020b7bd8 R08: ffffffff870225be R09: fffffbfff140652a
R10: fffffbfff140652a R11: 0000000000000000 R12: ffff8880925d35d0
R13: ffff8880925d3140 R14: dffffc0000000000 R15: 1ffff110124ba6ba
FS:  0000000001a0b880(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000000a6d6f000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 cipso_v4_sock_setattr+0x34b/0x470 net/ipv4/cipso_ipv4.c:1888
 netlbl_sock_setattr+0x2a7/0x310 net/netlabel/netlabel_kapi.c:989
 smack_netlabel security/smack/smack_lsm.c:2425 [inline]
 smack_inode_setsecurity+0x3da/0x4a0 security/smack/smack_lsm.c:2716
 security_inode_setsecurity+0xb2/0x140 security/security.c:1364
 __vfs_setxattr_noperm+0x16f/0x3e0 fs/xattr.c:197
 vfs_setxattr fs/xattr.c:224 [inline]
 setxattr+0x335/0x430 fs/xattr.c:451
 __do_sys_fsetxattr fs/xattr.c:506 [inline]
 __se_sys_fsetxattr+0x130/0x1b0 fs/xattr.c:495
 __x64_sys_fsetxattr+0xbf/0xd0 fs/xattr.c:495
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440199
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcadc19e48 EFLAGS: 00000246 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440199
RDX: 0000000020000200 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000003 R09: 00000000004002c8
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000401a20
R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000000
---[ end trace 9bbc7bb8e1061a42 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffffc900020b7b80 EFLAGS: 00010246
RAX: 1ffff110124ba600 RBX: 0000000000000000 RCX: ffff88809fefa600
RDX: ffff8880994cdb18 RSI: 0000000000000000 RDI: ffff8880925d3140
RBP: ffffc900020b7bd8 R08: ffffffff870225be R09: fffffbfff140652a
R10: fffffbfff140652a R11: 0000000000000000 R12: ffff8880925d35d0
R13: ffff8880925d3140 R14: dffffc0000000000 R15: 1ffff110124ba6ba
FS:  0000000001a0b880(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000000a6d6f000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/21 17:49 upstream ca7e1fd1026c bd2a74a3 .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/03/06 07:50 upstream 63623fd44972 c88c7b75 .config console log report ci-upstream-kasan-gce-smack-root
2020/03/03 02:47 upstream 63623fd44972 c88c7b75 .config console log report ci-upstream-kasan-gce-smack-root
2020/03/01 19:23 upstream 63623fd44972 c88c7b75 .config console log report ci-upstream-kasan-gce-smack-root
2020/02/29 19:41 upstream f8788d86ab28 59b57593 .config console log report ci-upstream-kasan-gce-smack-root
2020/02/26 12:08 upstream f8788d86ab28 59b57593 .config console log report ci-upstream-kasan-gce-smack-root
2020/02/25 12:10 upstream f8788d86ab28 59b57593 .config console log report ci-upstream-kasan-gce-smack-root
2020/02/21 17:24 upstream ca7e1fd1026c bd2a74a3 .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.