general protection fault in jffs2_sum_add_kvec

Status: moderation: reported on 2026/10/28 14:30
Subsystems: jffs2
[Documentation on labels]
Reported-by: syzbot+05faa47c9efde1bcdccd@syzkaller.appspotmail.com
First crash: 4d08h, last: 4d08h
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
3ad0b88c repro-c 💥 general protection fault in jffs2_sum_add_kvec 2026/10/27 00:01 2026/10/27 00:01 2026/10/27 10:05 168cb7a2
8f442b67 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ FuzzingArtifact: ❌ MemoryCorruption: ✅ NetworkNeedsSetup: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ general protection fault in jffs2_sum_add_kvec 2026/10/26 00:00 2026/10/26 00:00 2026/10/26 01:02 1d9ca40b
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in jffs2_sum_add_kvec jffs2 17 syz, C error done 10 913d 931d 0/29 auto-obsoleted due to no activity on 2024/07/18 14:03

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 6344 Comm: jffs2_gcd_mtd0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:jffs2_sum_add_kvec+0x65/0x1870 fs/jffs2/summary.c:254
Code: 4d 89 fe 49 c1 ee 03 41 80 3c 1e 00 74 12 4c 89 ff e8 bf fd f6 fe 48 b9 00 00 00 00 00 fc ff df 4d 8b 2f 4c 89 e8 48 c1 e8 03 <0f> b6 04 08 84 c0 0f 85 ef 0b 00 00 41 8b 5d 00 bf ff ff ff ff 89
RSP: 0018:ffffc90004147790 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000009000 R08: ffffc900041479e0 R09: 0000000000000000
R10: ffff88803e269720 R11: ffffffff81b24f80 R12: ffff888029d12000
R13: 0000000000000000 R14: 1ffff110053a24cf R15: ffff888029d12678
FS:  0000000000000000(0000) GS:ffff88812484d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555592777a28 CR3: 000000002efda000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 jffs2_flash_direct_writev+0xaa/0xe0 fs/jffs2/writev.c:22
 jffs2_mark_erased_block fs/jffs2/erase.c:436 [inline]
 jffs2_erase_pending_blocks+0x1375/0x2400 fs/jffs2/erase.c:116
 jffs2_garbage_collect_pass+0x6cc/0x2170 fs/jffs2/gc.c:253
 jffs2_garbage_collect_thread+0x693/0x720 fs/jffs2/background.c:155
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:jffs2_sum_add_kvec+0x65/0x1870 fs/jffs2/summary.c:254
Code: 4d 89 fe 49 c1 ee 03 41 80 3c 1e 00 74 12 4c 89 ff e8 bf fd f6 fe 48 b9 00 00 00 00 00 fc ff df 4d 8b 2f 4c 89 e8 48 c1 e8 03 <0f> b6 04 08 84 c0 0f 85 ef 0b 00 00 41 8b 5d 00 bf ff ff ff ff 89
RSP: 0018:ffffc90004147790 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000009000 R08: ffffc900041479e0 R09: 0000000000000000
R10: ffff88803e269720 R11: ffffffff81b24f80 R12: ffff888029d12000
R13: 0000000000000000 R14: 1ffff110053a24cf R15: ffff888029d12678
FS:  0000000000000000(0000) GS:ffff88812484d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555592777a28 CR3: 0000000038646000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	4d 89 fe             	mov    %r15,%r14
   3:	49 c1 ee 03          	shr    $0x3,%r14
   7:	41 80 3c 1e 00       	cmpb   $0x0,(%r14,%rbx,1)
   c:	74 12                	je     0x20
   e:	4c 89 ff             	mov    %r15,%rdi
  11:	e8 bf fd f6 fe       	call   0xfef6fdd5
  16:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  1d:	fc ff df
  20:	4d 8b 2f             	mov    (%r15),%r13
  23:	4c 89 e8             	mov    %r13,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 ef 0b 00 00    	jne    0xc25
  36:	41 8b 5d 00          	mov    0x0(%r13),%ebx
  3a:	bf ff ff ff ff       	mov    $0xffffffff,%edi
  3f:	89                   	.byte 0x89

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/24 14:24 upstream 5b0764a53235 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in jffs2_sum_add_kvec
* Struck through repros no longer work on HEAD.