syzbot


general protection fault in dtSplitUp

Status: upstream: reported C repro on 2022/10/01 13:49
Reported-by: syzbot+172bdd582e5d63486948@syzkaller.appspotmail.com
First crash: 63d, last: 9d17h

Cause bisection: failed (bisect log)
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 general protection fault in dtSplitUp C error 1 50d 50d 0/1 upstream: reported C repro on 2022/10/13 16:49
linux-4.14 general protection fault in dtSplitUp C inconclusive 1 49d 49d 0/1 upstream: reported C repro on 2022/10/15 11:58

Sample crash report:
loop0: detected capacity change from 0 to 32768
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 3609 Comm: syz-executor133 Not tainted 6.1.0-rc1-syzkaller-00454-ga70385240892 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:dtExtendPage fs/jfs/jfs_dtree.c:1661 [inline]
RIP: 0010:dtSplitUp+0x1526/0x5130 fs/jfs/jfs_dtree.c:1034
Code: c6 74 11 e8 5c 2d 9f fe 48 8b 44 24 20 49 8d 5e e8 48 89 18 e8 4b 2d 9f fe 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 92 35 00 00 4c 8b 33 31 ff 4c 89 f6 e8 13 2a 9f
RSP: 0018:ffffc90003e5f780 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff82dd5e55 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008c07e R12: 0000000000000000
R13: ffff88806f48b33a R14: ffffc90003e5fca8 R15: ffff88806f48b270
FS:  000055555568a300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a8d0b505b8 CR3: 000000001f93e000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 dtInsert+0x82b/0xa10 fs/jfs/jfs_dtree.c:863
 jfs_create+0x5b7/0xac0 fs/jfs/namei.c:137
 vfs_create fs/namei.c:3115 [inline]
 vfs_create+0x3e9/0x670 fs/namei.c:3101
 do_mknodat+0x3d9/0x530 fs/namei.c:3964
 __do_sys_mknodat fs/namei.c:3992 [inline]
 __se_sys_mknodat fs/namei.c:3989 [inline]
 __x64_sys_mknodat+0xaa/0xe0 fs/namei.c:3989
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb984345eb9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffe9455da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fb984345eb9
RDX: 0000000000000008 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00007fb984305680 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000103 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00083878000000f8 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dtExtendPage fs/jfs/jfs_dtree.c:1661 [inline]
RIP: 0010:dtSplitUp+0x1526/0x5130 fs/jfs/jfs_dtree.c:1034
Code: c6 74 11 e8 5c 2d 9f fe 48 8b 44 24 20 49 8d 5e e8 48 89 18 e8 4b 2d 9f fe 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 92 35 00 00 4c 8b 33 31 ff 4c 89 f6 e8 13 2a 9f
RSP: 0018:ffffc90003e5f780 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff82dd5e55 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008c07e R12: 0000000000000000
R13: ffff88806f48b33a R14: ffffc90003e5fca8 R15: ffff88806f48b270
FS:  000055555568a300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558122ad8cd8 CR3: 000000001f93e000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	74 11                	je     0x13
   2:	e8 5c 2d 9f fe       	callq  0xfe9f2d63
   7:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   c:	49 8d 5e e8          	lea    -0x18(%r14),%rbx
  10:	48 89 18             	mov    %rbx,(%rax)
  13:	e8 4b 2d 9f fe       	callq  0xfe9f2d63
  18:	48 89 da             	mov    %rbx,%rdx
  1b:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  22:	fc ff df
  25:	48 c1 ea 03          	shr    $0x3,%rdx
* 29:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2d:	0f 85 92 35 00 00    	jne    0x35c5
  33:	4c 8b 33             	mov    (%rbx),%r14
  36:	31 ff                	xor    %edi,%edi
  38:	4c 89 f6             	mov    %r14,%rsi
  3b:	e8                   	.byte 0xe8
  3c:	13 2a                	adc    (%rdx),%ebp
  3e:	9f                   	lahf

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2022/11/23 21:33 upstream 4312098baf37 23bf86af .config log report syz C
* Struck through repros no longer work on HEAD.
Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2022/10/24 11:53 upstream a70385240892 23bf86af .config log report syz C general protection fault in dtSplitUp
ci-upstream-kasan-gce-root 2022/10/01 04:37 upstream 5a77386984b5 feb56351 .config log report syz C general protection fault in dtSplitUp
* Struck through repros no longer work on HEAD.