WARNING in add_mtd_blktrans_dev

Status: upstream: reported syz repro on 2026/10/05 20:45
Reported-by: syzbot+9afce4e0f0634f7137d9@syzkaller.appspotmail.com
First crash: 13d, last: 13h05m

Sample crash report:
RBP: 00007efc7ae86ab8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efc7b076fac R14: 00007efc7b076fa0 R15: 00007efc7b076fa0
 </TASK>
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4450 at block/genhd.c:554 device_add_disk+0x8d6/0xde0 block/genhd.c:552
Modules linked in:
CPU: 0 PID: 4450 Comm: syz.0.51 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:device_add_disk+0x8d6/0xde0 block/genhd.c:554
Code: 04 48 89 d8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 8f 03 00 00 8b 33 48 c7 c7 00 f4 70 8d e8 b1 3d 37 00 eb 05 e8 ea 04 a6 fd <0f> 0b 41 bd 01 00 00 00 44 89 e8 48 83 c4 50 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900031ef470 EFLAGS: 00010293
RAX: ffffffff83d31e76 RBX: ffff88806aae0000 RCX: ffff88802cfe8000
RDX: 0000000000000000 RSI: 000000000000001f RDI: 0000000000000103
RBP: 000000000000001f R08: ffff888076dbc1db R09: 1ffff1100edb783b
R10: dffffc0000000000 R11: ffffed100edb783c R12: ffff88805cc85e40
R13: ffff88806aae0150 R14: dffffc0000000000 R15: ffff88805cc85e40
FS:  0000555591911500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000003ca2f90a000 CR3: 000000007931a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 add_mtd_blktrans_dev+0xfb1/0x13f0 drivers/mtd/mtd_blkdevs.c:387
 mtdblock_add_mtd+0x186/0x240 drivers/mtd/mtdblock.c:333
 blktrans_notify_add+0x95/0xe0 drivers/mtd/mtd_blkdevs.c:464
 add_mtd_device+0xd40/0x1260 drivers/mtd/mtdcore.c:693
 mtd_add_partition+0x25d/0x420 drivers/mtd/mtdpart.c:273
 mtdchar_blkpg_ioctl+0x283/0x2b0 drivers/mtd/mtdchar.c:562
 mtdchar_ioctl+0x14cb/0x1d70 drivers/mtd/mtdchar.c:1010
 mtdchar_unlocked_ioctl+0xad/0xd0 drivers/mtd/mtdchar.c:1033
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7efc7adef559
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:00007ffc04cc9018 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007efc7b076fa0 RCX: 00007efc7adef559
RDX: 0000200000001940 RSI: 0000000000001269 RDI: 0000000000000004
RBP: 00007efc7ae86ab8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efc7b076fac R14: 00007efc7b076fa0 R15: 00007efc7b076fa0
 </TASK>

Crashes (54):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/17 21:53 linux-5.15.y 792fbe1537d8 432c0077 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/16 10:05 linux-5.15.y 792fbe1537d8 3f2522c6 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 18:55 linux-5.15.y a051a4bf909f 4f92358f .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 09:45 linux-5.15.y a051a4bf909f 4f92358f .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 07:37 linux-5.15.y a051a4bf909f b2734a59 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 07:09 linux-5.15.y a051a4bf909f b2734a59 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 06:30 linux-5.15.y a051a4bf909f b2734a59 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 05:47 linux-5.15.y a051a4bf909f b2734a59 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 03:57 linux-5.15.y a051a4bf909f b2734a59 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/07 02:12 linux-5.15.y a051a4bf909f f7710056 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 17:40 linux-5.15.y a051a4bf909f f7710056 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 16:46 linux-5.15.y a051a4bf909f f7710056 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 13:59 linux-5.15.y a051a4bf909f f7710056 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 13:03 linux-5.15.y a051a4bf909f f7710056 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/18 09:48 linux-5.15.y 792fbe1537d8 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/17 20:16 linux-5.15.y 792fbe1537d8 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/16 21:08 linux-5.15.y 792fbe1537d8 4c840a2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/16 19:49 linux-5.15.y 792fbe1537d8 4c840a2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/16 02:03 linux-5.15.y 792fbe1537d8 3f2522c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/15 10:34 linux-5.15.y a051a4bf909f 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/14 16:57 linux-5.15.y a051a4bf909f 1a71827b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 19:58 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 19:55 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 19:53 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 19:43 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 19:41 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 18:15 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/11 18:07 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 10:37 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 10:36 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 09:04 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 03:20 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 03:20 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 01:06 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/10 01:06 linux-5.15.y a051a4bf909f 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 11:52 linux-5.15.y a051a4bf909f b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 11:50 linux-5.15.y a051a4bf909f b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 06:58 linux-5.15.y a051a4bf909f b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 00:37 linux-5.15.y a051a4bf909f b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 00:37 linux-5.15.y a051a4bf909f b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 00:34 linux-5.15.y a051a4bf909f b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/09 00:34 linux-5.15.y a051a4bf909f b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 15:56 linux-5.15.y a051a4bf909f f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 15:50 linux-5.15.y a051a4bf909f f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 12:07 linux-5.15.y a051a4bf909f f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/06 12:04 linux-5.15.y a051a4bf909f f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/05 20:44 linux-5.15.y a051a4bf909f af63e995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
2026/10/05 20:44 linux-5.15.y a051a4bf909f af63e995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in add_mtd_blktrans_dev
* Struck through repros no longer work on HEAD.