kernel BUG in jffs2_sum_write_sumnode (2)

Status: upstream: reported on 2026/09/06 12:10
Subsystems: jffs2
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+0727f46a0571de01bf93@syzkaller.appspotmail.com
First crash: 4d05h, last: 1d05h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
4d5e4863 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ kernel BUG in jffs2_sum_write_sumnode (2) 2026/09/04 06:51 2026/09/04 06:51 2026/09/04 07:40 801f0966
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [jffs2?] kernel BUG in jffs2_sum_write_sumnode (2) 0 (1) 2026/09/06 12:10
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 kernel BUG in jffs2_sum_write_sumnode -1 2 22d 22d 0/3 upstream: reported on 2026/08/15 05:15
upstream kernel BUG in jffs2_sum_write_sumnode jffs2 -1 4 875d 877d 0/29 auto-obsoleted due to no activity on 2024/07/23 08:54

Sample crash report:
jffs2: warning: (10801) jffs2_sum_write_sumnode: Empty summary info!!!
------------[ cut here ]------------
------------[ cut here ]------------
kernel BUG at fs/jffs2/summary.c:868!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 10801 Comm: syz.9.661 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:jffs2_sum_write_sumnode.cold+0x4e/0x174 fs/jffs2/summary.c:868
Code: 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 2c 01 00 00 8b b3 40 06 00 00 48 c7 c2 00 76 33 8c 48 c7 c7 00 72 33 8c e8 cd 73 f8 ff 90 <0f> 0b e8 45 f9 e1 00 65 4c 8b 3d 65 1a 62 13 b8 ff ff 37 00 48 c1
RSP: 0018:ffffc90003a56d90 EFLAGS: 00010282
RAX: 0000000000000046 RBX: ffff8880375f8000 RCX: 0000000000000000
RDX: 0000000000000046 RSI: ffffffff81e9c5d9 RDI: fffff5200074ada3
RBP: ffffc90003a56f10 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000000 R11: 0000000000000001 R12: ffff88807e062a00
R13: 0000000000000000 R14: 0000000000000f40 R15: 0000000000000000
FS:  00007f34bbf8d6c0(0000) GS:ffff888123b61000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557616249078 CR3: 0000000074bae000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 jffs2_do_reserve_space+0xb94/0xf70 fs/jffs2/nodemgmt.c:392
 jffs2_reserve_space_gc+0x6b/0xf0 fs/jffs2/nodemgmt.c:226
 jffs2_garbage_collect_pristine+0x103/0x870 fs/jffs2/gc.c:613
 jffs2_garbage_collect_live+0x1471/0x36b0 fs/jffs2/gc.c:546
 jffs2_garbage_collect_pass+0xb28/0x1b40 fs/jffs2/gc.c:464
 jffs2_reserve_space+0x489/0xbb0 fs/jffs2/nodemgmt.c:171
 jffs2_write_inode_range+0x275/0xb80 fs/jffs2/write.c:362
 jffs2_write_end+0x72c/0xea0 fs/jffs2/file.c:299
 generic_perform_write+0x513/0xa40 mm/filemap.c:4395
 __generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4491
 generic_file_write_iter+0xe1/0x390 mm/filemap.c:4517
 iter_file_splice_write+0x830/0x10b0 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x192/0x690 fs/splice.c:1159
 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1228
 do_sendfile+0xadc/0xe20 fs/read_write.c:1371
 __do_sys_sendfile64 fs/read_write.c:1432 [inline]
 __se_sys_sendfile64 fs/read_write.c:1418 [inline]
 __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1418
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f34bb19e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34bbf8d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f34bb426090 RCX: 00007f34bb19e159
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000009
RBP: 00007f34bb235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000020000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f34bb426128 R14: 00007f34bb426090 R15: 00007ffc4299d258
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:jffs2_sum_write_sumnode.cold+0x4e/0x174 fs/jffs2/summary.c:868
Code: 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 2c 01 00 00 8b b3 40 06 00 00 48 c7 c2 00 76 33 8c 48 c7 c7 00 72 33 8c e8 cd 73 f8 ff 90 <0f> 0b e8 45 f9 e1 00 65 4c 8b 3d 65 1a 62 13 b8 ff ff 37 00 48 c1
RSP: 0018:ffffc90003a56d90 EFLAGS: 00010282
RAX: 0000000000000046 RBX: ffff8880375f8000 RCX: 0000000000000000
RDX: 0000000000000046 RSI: ffffffff81e9c5d9 RDI: fffff5200074ada3
RBP: ffffc90003a56f10 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000000 R11: 0000000000000001 R12: ffff88807e062a00
R13: 0000000000000000 R14: 0000000000000f40 R15: 0000000000000000
FS:  00007f34bbf8d6c0(0000) GS:ffff888123c61000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe398fd0000 CR3: 0000000074bae000 CR4: 0000000000350ef0

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/02 12:00 upstream 89a312991dc6 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root kernel BUG in jffs2_sum_write_sumnode
2026/09/05 11:53 linux-next 9d80aa4617b3 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce kernel BUG in jffs2_sum_write_sumnode
* Struck through repros no longer work on HEAD.