WARNING in bitmap_parse_user

Status: upstream: reported C repro on 2026/08/06 12:00
Reported-by: syzbot+9278fd3e9041a9869efa@syzkaller.appspotmail.com
First crash: 54d, last: 14h01m
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in bitmap_parse_user origin:lts-only -1 syz, C 50 12h56m 60d 0/3 upstream: reported C repro on 2026/07/31 03:46
linux-6.6 WARNING in bitmap_parse_user origin:lts-only -1 syz, C error 16 2d02h 60d 0/2 upstream: reported C repro on 2026/07/31 03:39
android-6-12 WARNING in bitmap_parse_user origin:lts -1 syz, C 43 3h01m 61d 0/1 premoderation: reported C repro on 2026/07/30 09:20
upstream WARNING in bitmap_parse_user trace -1 syz, C 83 632d 653d 28/29 fixed on 2025/05/06 15:33

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4426 at mm/page_alloc.c:5476 current_gfp_context include/linux/sched/mm.h:-1 [inline]
WARNING: CPU: 0 PID: 4426 at mm/page_alloc.c:5476 __alloc_pages+0x39f/0x480 mm/page_alloc.c:5488
Modules linked in:
CPU: 0 PID: 4426 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__alloc_pages+0x39f/0x480 mm/page_alloc.c:5476
Code: 31 ff e9 b1 fe ff ff e8 6f c8 0b 08 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 4f fd ff ff 4c 89 e7 e8 36 d3 09 00 e9 42 fd ff ff <0f> 0b 45 31 ff e9 ee fe ff ff 65 44 8b 2d 17 c9 4d 7e 41 83 fd 08
RSP: 0018:ffffc90002fdfa00 EFLAGS: 00010246
RAX: ffffc90002fdfa40 RBX: 1ffff920005fbf44 RCX: 0000000000000000
RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90002fdfa68
RBP: ffffc90002fdfaf0 R08: ffffc90002fdfa67 R09: ffffc90002fdfa40
R10: dffffc0000000000 R11: fffff520005fbf4d R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000040cc0 R15: 0000000000000013
FS:  0000555562aef500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558c23781950 CR3: 00000000245b8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kmalloc_order+0x40/0x150 mm/slab_common.c:986
 kmalloc_order_trace+0x14/0xf0 mm/slab_common.c:1002
 memdup_user_nul+0x23/0xf0 mm/util.c:260
 bitmap_parse_user+0x1f/0x60 lib/bitmap.c:453
 cpumask_parse_user include/linux/cpumask.h:623 [inline]
 write_irq_affinity kernel/irq/proc.c:153 [inline]
 irq_affinity_proc_write+0x107/0x1d0 kernel/irq/proc.c:182
 pde_write fs/proc/inode.c:335 [inline]
 proc_reg_write+0x1dd/0x2c0 fs/proc/inode.c:347
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 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: 0033:0x7f90ea71d0d9
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:00007ffc73422fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f90ea9a4fa0 RCX: 00007f90ea71d0d9
RDX: 00000000fffffcf0 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f90ea7b4024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f90ea9a4fac R14: 00007f90ea9a4fa0 R15: 00007f90ea9a4fa0
 </TASK>

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/06 12:58 linux-5.15.y 6e2fd6534337 cd5b1963 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/29 12:53 linux-5.15.y 0248c33e835e 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/29 12:52 linux-5.15.y 0248c33e835e 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/27 20:29 linux-5.15.y 0248c33e835e a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/27 20:29 linux-5.15.y 0248c33e835e a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/22 00:56 linux-5.15.y 0248c33e835e 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/22 00:55 linux-5.15.y 0248c33e835e 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/11 07:50 linux-5.15.y 0996e0926f6b 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/11 07:50 linux-5.15.y 0996e0926f6b 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/10 23:58 linux-5.15.y 0996e0926f6b 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/10 23:56 linux-5.15.y 0996e0926f6b 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/10 08:10 linux-5.15.y 0996e0926f6b 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/10 08:09 linux-5.15.y 0996e0926f6b 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/05 07:00 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/05 06:59 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/04 18:22 linux-5.15.y 0996e0926f6b f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/09/04 18:21 linux-5.15.y 0996e0926f6b f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/20 19:10 linux-5.15.y 0eb903b5b519 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/20 19:07 linux-5.15.y 0eb903b5b519 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/20 13:25 linux-5.15.y 0eb903b5b519 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/20 13:25 linux-5.15.y 0eb903b5b519 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/14 18:54 linux-5.15.y aabd761612db 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/14 18:54 linux-5.15.y aabd761612db 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/06 12:01 linux-5.15.y 6e2fd6534337 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
2026/08/06 11:59 linux-5.15.y 6e2fd6534337 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in bitmap_parse_user
* Struck through repros no longer work on HEAD.