syzbot
WARNING in bitmap_parse_user
Status:
premoderation: reported C repro on 2026/07/30 09:20
Reported-by: syzbot+336fc9f8bcc9db1e8405@syzkaller.appspotmail.com
First crash: 8d03h, last: 4h21m
Sample crash report:
WARNING: CPU: 0 PID: 313 at mm/page_alloc.c:5285 __alloc_pages_noprof+0x109/0x7e0 mm/page_alloc.c:5285
Modules linked in:
CPU: 0 UID: 0 PID: 313 Comm: syz-executor232 Not tainted syzkaller #0 28dc4f15f82f041c91cead1444746a7bfe1433af
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__alloc_pages_noprof+0x109/0x7e0 mm/page_alloc.c:5285
Code: 00 0f 1f 44 00 00 83 fb 0b 72 28 b8 00 20 00 00 23 44 24 40 75 1d 80 3d d4 d8 0b 06 00 0f 85 c2 00 00 00 c6 05 c7 d8 0b 06 01 <0f> 0b 31 c0 e9 b4 00 00 00 83 fb 0a 0f 87 a9 00 00 00 44 8b 64 24
RSP: 0018:ffffc9000120f8c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000013 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc9000120f978
RBP: ffffc9000120f9f0 R08: ffffc9000120f977 R09: 0000000000000000
R10: ffffc9000120f960 R11: fffff52000241f2f R12: ffffc9000120f900
R13: dffffc0000000000 R14: 1ffff92000241f1c R15: 0000000000000000
FS: 00005555564ad3c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005599c0ddd000 CR3: 000000012e664000 CR4: 00000000003526b0
Call Trace:
<TASK>
___kmalloc_large_node+0x81/0x220 mm/slub.c:-1
__kmalloc_large_node_noprof+0x1e/0xd0 mm/slub.c:4367
__do_kmalloc_node mm/slub.c:4383 [inline]
__kmalloc_node_track_caller_noprof+0x30d/0x4f0 mm/slub.c:4414
memdup_user_nul+0x40/0x1a0 mm/util.c:319
bitmap_parse_user+0x29/0x80 lib/bitmap-str.c:31
cpumask_parse_user include/linux/cpumask.h:876 [inline]
write_irq_affinity kernel/irq/proc.c:151 [inline]
irq_affinity_proc_write+0x139/0x230 kernel/irq/proc.c:180
pde_write fs/proc/inode.c:330 [inline]
proc_reg_write+0x1f7/0x2f0 fs/proc/inode.c:342
vfs_write+0x3c1/0xfd0 fs/read_write.c:682
ksys_write+0x145/0x260 fs/read_write.c:737
__do_sys_write fs/read_write.c:749 [inline]
__se_sys_write fs/read_write.c:746 [inline]
__x64_sys_write+0x7f/0x90 fs/read_write.c:746
x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f44065ffc39
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe10e0e3a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000020000000
* Struck through repros no longer work on HEAD.