WARNING: zero-size vmalloc in disksize_store

Status: upstream: reported C repro on 2026/09/21 08:16
Reported-by: syzbot+876234f10f1ff7f267e7@syzkaller.appspotmail.com
First crash: 3d08h, last: 3d06h
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING: zero-size vmalloc in disksize_store -1 syz, C 3 3d05h 3d07h 0/3 upstream: reported C repro on 2026/09/21 09:25
linux-6.6 WARNING: zero-size vmalloc in disksize_store -1 syz, C 3 3d04h 3d04h 0/2 upstream: reported C repro on 2026/09/21 11:39
upstream WARNING: zero-size vmalloc in disksize_store block prio:low -1 syz, C 4 3d06h 3d00h 0/29 upstream: reported C repro on 2026/09/21 15:53

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4434 at mm/vmalloc.c:3227 __vmalloc_node_range+0x133b/0x1380 mm/vmalloc.c:3227
Modules linked in:
CPU: 0 PID: 4434 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__vmalloc_node_range+0x133b/0x1380 mm/vmalloc.c:3227
Code: 00 80 23 df 48 8b 44 24 50 42 80 3c 38 00 48 8b 5c 24 70 74 08 48 89 df e8 e2 e4 0c 00 48 8b 1b e9 0e ff ff ff e8 15 a0 bb ff <0f> 0b 31 db e9 00 ff ff ff e8 77 f5 6b 08 e8 02 a0 bb ff 0f 0b e8
RSP: 0018:ffffc90003457a60 EFLAGS: 00010293
RAX: ffffffff81c692cb RBX: 0000000000000000 RCX: ffff88801eeada00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003457c18 R08: 0000000000000dc0 R09: 8000000000000163
R10: dffffc0000000000 R11: ffffed1028762186 R12: ffffe8ffffffffff
R13: 0000000000000dc0 R14: ffffffff85227e01 R15: dffffc0000000000
FS:  0000555568229500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f46e0c70050 CR3: 00000000177a7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __vmalloc_node mm/vmalloc.c:3365 [inline]
 vzalloc+0x75/0x80 mm/vmalloc.c:3438
 zram_meta_alloc drivers/block/zram/zram_drv.c:1188 [inline]
 disksize_store+0xe1/0x330 drivers/block/zram/zram_drv.c:1765
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f46e0d9e159
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:00007ffe7363c0b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f46e1025fa0 RCX: 00007f46e0d9e159
RDX: 0000000000000012 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f46e0e3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f46e1025fac R14: 00007f46e1025fa0 R15: 00007f46e1025fa0
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/21 09:58 linux-6.1.y 1a8763b93150 853b104b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: zero-size vmalloc in disksize_store
2026/09/21 09:25 linux-6.1.y 1a8763b93150 853b104b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: zero-size vmalloc in disksize_store
2026/09/21 08:50 linux-6.1.y 1a8763b93150 853b104b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: zero-size vmalloc in disksize_store
2026/09/21 08:18 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: zero-size vmalloc in disksize_store
2026/09/21 08:16 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: zero-size vmalloc in disksize_store
2026/09/21 09:09 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING: zero-size vmalloc in disksize_store
2026/09/21 09:09 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING: zero-size vmalloc in disksize_store
2026/09/21 09:07 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING: zero-size vmalloc in disksize_store
* Struck through repros no longer work on HEAD.