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general protection fault in prepare_to_wait (2)

Status: fixed on 2023/10/12 12:47
Subsystems: hams
[Documentation on labels]
Reported-by: syzbot+666c97e4686410e79649@syzkaller.appspotmail.com
Fix commit: c2f8fd794960 netrom: Deny concurrent connect().
First crash: 256d, last: 214d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: BUG: unable to handle kernel NULL pointer dereference in prepare_to_wait (log)
Repro: syz .config
  
▶ ▼ Discussions (4)
Title Replies (including bot) Last reply
[PATCH v1 net] netrom: Deny concurrent connect(). 2 (2) 2023/08/28 06:00
[PATCH] sock: Fix sk_sleep return invalid pointer 3 (3) 2023/08/23 00:19
[syzbot] Monthly hams report (Aug 2023) 0 (1) 2023/08/21 20:42
[syzbot] [hams?] general protection fault in prepare_to_wait (2) 0 (1) 2023/08/18 16:36
▶ ▼ Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 general protection fault in prepare_to_wait C error 11 527d 1777d 0/1 upstream: reported C repro on 2019/06/16 06:33
linux-4.19 general protection fault in prepare_to_wait C error 29 505d 1719d 0/1 upstream: reported C repro on 2019/08/12 18:19
upstream general protection fault in prepare_to_wait hams C done error 285 455d 1940d 0/26 auto-obsoleted due to no activity on 2023/05/27 16:21
android-5-10 KASAN: null-ptr-deref Write in prepare_to_wait C error 2 910d 910d 1/2 fixed on 2021/12/01 19:46
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2023/08/22 08:02 39m eadavis@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git ace0ab3a4b54 OK log
2023/08/22 02:20 32m eadavis@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ace0ab3a4b54 report log
2023/08/22 01:24 20m eadavis@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ace0ab3a4b54 report log
2023/08/19 06:27 19m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git ace0ab3a4b54 OK log
2023/08/19 02:25 1h37m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git ace0ab3a4b54 error OK

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 PID: 5059 Comm: syz-executor.0 Not tainted 6.5.0-rc5-syzkaller-00194-gace0ab3a4b54 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:__lock_acquire+0x109/0x5de0 kernel/locking/lockdep.c:5012
Code: 45 85 c9 0f 84 cc 0e 00 00 44 8b 05 11 6e 23 0b 45 85 c0 0f 84 be 0d 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 d1 48 c1 e9 03 <80> 3c 11 00 0f 85 e8 40 00 00 49 81 3a a0 69 48 90 0f 84 96 0d 00
RSP: 0018:ffffc90003d6f9e0 EFLAGS: 00010006
RAX: ffff8880244c8000 RBX: 1ffff920007adf6c RCX: 0000000000000003
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000018
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000018 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f51d519a6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f51d5158d58 CR3: 000000002943f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5761 [inline]
 lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162
 prepare_to_wait+0x47/0x380 kernel/sched/wait.c:269
 nr_accept+0x20d/0x650 net/netrom/af_netrom.c:798
 do_accept+0x3a6/0x570 net/socket.c:1872
 __sys_accept4_file net/socket.c:1913 [inline]
 __sys_accept4+0x99/0x120 net/socket.c:1943
 __do_sys_accept4 net/socket.c:1954 [inline]
 __se_sys_accept4 net/socket.c:1951 [inline]
 __x64_sys_accept4+0x96/0x100 net/socket.c:1951
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f51d447cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f51d519a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000120
RAX: ffffffffffffffda RBX: 00007f51d459bf80 RCX: 00007f51d447cae9
RDX: 0000000020000400 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f51d44c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000800 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f51d459bf80 R15: 00007ffc25c34e48
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x109/0x5de0 kernel/locking/lockdep.c:5012
Code: 45 85 c9 0f 84 cc 0e 00 00 44 8b 05 11 6e 23 0b 45 85 c0 0f 84 be 0d 00 00 48 ba 00 00 00 00 00 fc ff df 4c 89 d1 48 c1 e9 03 <80> 3c 11 00 0f 85 e8 40 00 00 49 81 3a a0 69 48 90 0f 84 96 0d 00
RSP: 0018:ffffc90003d6f9e0 EFLAGS: 00010006
RAX: ffff8880244c8000 RBX: 1ffff920007adf6c RCX: 0000000000000003
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000018
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000018 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f51d519a6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f51d5158d58 CR3: 000000002943f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	45 85 c9             	test   %r9d,%r9d
   3:	0f 84 cc 0e 00 00    	je     0xed5
   9:	44 8b 05 11 6e 23 0b 	mov    0xb236e11(%rip),%r8d        # 0xb236e21
  10:	45 85 c0             	test   %r8d,%r8d
  13:	0f 84 be 0d 00 00    	je     0xdd7
  19:	48 ba 00 00 00 00 00 	movabs $0xdffffc0000000000,%rdx
  20:	fc ff df
  23:	4c 89 d1             	mov    %r10,%rcx
  26:	48 c1 e9 03          	shr    $0x3,%rcx
* 2a:	80 3c 11 00          	cmpb   $0x0,(%rcx,%rdx,1) <-- trapping instruction
  2e:	0f 85 e8 40 00 00    	jne    0x411c
  34:	49 81 3a a0 69 48 90 	cmpq   $0xffffffff904869a0,(%r10)
  3b:	0f                   	.byte 0xf
  3c:	84                   	.byte 0x84
  3d:	96                   	xchg   %eax,%esi
  3e:	0d                   	.byte 0xd

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/14 18:20 net ace0ab3a4b54 39990d51 .config strace log report syz [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in prepare_to_wait
2023/08/20 05:07 net-next 4025d3e73abd d216d8a0 .config console log report syz [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce general protection fault in prepare_to_wait
2023/09/25 10:43 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe4469582053 0b6a67ac .config console log report syz [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in prepare_to_wait
2023/08/14 16:24 net ace0ab3a4b54 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in prepare_to_wait
* Struck through repros no longer work on HEAD.