WARNING in bitmap_parse_user

Status: upstream: reported C repro on 2026/07/31 03:46
Reported-by: syzbot+1f95abaf50735b83527d@syzkaller.appspotmail.com
First crash: 35d, last: 7h11m
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in bitmap_parse_user -1 syz, C 11 6h11m 29d 0/3 upstream: reported C repro on 2026/08/06 12:00
linux-6.6 WARNING in bitmap_parse_user origin:lts-only -1 syz, C 10 15d 35d 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 28 12h03m 36d 0/1 premoderation: reported C repro on 2026/07/30 09:20
upstream WARNING in bitmap_parse_user trace -1 syz, C 83 607d 628d 28/29 fixed on 2025/05/06 15:33

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4424 at mm/page_alloc.c:5634 __alloc_pages+0x2fe/0x4f0 mm/page_alloc.c:5634
Modules linked in:
CPU: 0 PID: 4424 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+0x2fe/0x4f0 mm/page_alloc.c:5634
Code: 0c 25 28 00 00 00 48 3b 8c 24 a0 00 00 00 0f 85 9f 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 c6 05 16 a1 44 0c 01 <0f> 0b eb a4 a9 00 00 08 00 8b 74 24 04 75 3e 44 89 f1 81 e1 7f ff
RSP: 0018:ffffc900041b7a20 EFLAGS: 00010246
RAX: ffffc900041b7a00 RBX: 1ffff92000836f48 RCX: 0000000000000000
RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc900041b7a88
RBP: ffffc900041b7b10 R08: ffffc900041b7a87 R09: ffffc900041b7a60
R10: dffffc0000000000 R11: fffff52000836f51 R12: 0000000000000013
R13: 0000000000000000 R14: 0000000000040cc0 R15: dffffc0000000000
FS:  000055555a859500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e663fff CR3: 00000000293cc000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x8c/0x1f0 mm/slab_common.c:1077
 __do_kmalloc_node mm/slab_common.c:924 [inline]
 __kmalloc_node_track_caller+0x10f/0x240 mm/slab_common.c:956
 memdup_user_nul+0x28/0xf0 mm/util.c:261
 bitmap_parse_user+0x1f/0x60 lib/bitmap.c:464
 cpumask_parse_user include/linux/cpumask.h:725 [inline]
 write_irq_affinity+0x1bc/0x310 kernel/irq/proc.c:153
 pde_write fs/proc/inode.c:340 [inline]
 proc_reg_write+0x1dd/0x2c0 fs/proc/inode.c:352
 vfs_write+0x2dc/0x9a0 fs/read_write.c:582
 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: 0033:0x7f6f08b9e019
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:00007ffdf77a79f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6f08e25fa0 RCX: 00007f6f08b9e019
RDX: 00000000fffffdd4 RSI: 0000200000000340 RDI: 0000000000000003
RBP: 00007f6f08c3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6f08e25fac R14: 00007f6f08e25fa0 R15: 00007f6f08e25fa0
 </TASK>

Crashes (26):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/02 08:23 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/09/04 17:23 linux-6.1.y cf82dcca9634 f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/26 08:02 linux-6.1.y 05208478041c 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/26 08:02 linux-6.1.y 05208478041c 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/20 18:57 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/20 18:55 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/20 15:45 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/20 15:45 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/14 22:37 linux-6.1.y e4f7d8be268e 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/14 22:37 linux-6.1.y e4f7d8be268e 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/06 04:42 linux-6.1.y fb28aa725e05 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/08/06 04:42 linux-6.1.y fb28aa725e05 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/07/31 03:46 linux-6.1.y fb28aa725e05 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/07/31 03:46 linux-6.1.y fb28aa725e05 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in bitmap_parse_user
2026/09/04 15:58 linux-6.1.y cf82dcca9634 f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/09/04 15:58 linux-6.1.y cf82dcca9634 f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/09/04 15:58 linux-6.1.y cf82dcca9634 f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/25 22:22 linux-6.1.y 05208478041c a9a1fc32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/25 22:22 linux-6.1.y 05208478041c a9a1fc32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/20 14:48 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/20 14:46 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/20 14:44 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/20 06:44 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/20 06:44 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/14 17:30 linux-6.1.y e4f7d8be268e 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
2026/08/14 17:30 linux-6.1.y e4f7d8be268e 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in bitmap_parse_user
* Struck through repros no longer work on HEAD.