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 Fuu3UW32 wFbQw3wz1jF7CpFkxsPvUjfr28UUkGAqmUaIFZGQEpNhlub0wblgDeAX5ynosymYQmQzP8/gHglyK9WM+h8GPIeUNfdr+taq73GkWwXFucrhtmmxqfI8ypIgeMAbfsUl/9uTRxaFzVMBD2L2SDsp9+Q3WwyETWoo0hx2UOy4VAgi2gdgA7wYiRexQ7sFCuJf6AhIgKq9rnf1z0bzgC5mYE4eLqA94wuz5N5ubcnGmAVUmK3ma78ub75W75/OGPi6 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > Date: Sun, 03 May 2026 04:47:26 -0700 [thread overview] > Hello, > > syzbot found the following issue on: > > HEAD commit: dca922e019dd Merge tag 'xsa48x-7.1-tag' of git://git.kerne.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=100242ce580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=d0f0911eedbc130a > dashboard link: https://syzkaller.appspot.com/bug?extid=a21650c1666eae7b2aae > compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 > userspace arch: i386 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-dca922e0.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/1e719cb224ff/vmlinux-dca922e0.xz > kernel image: https://storage.googleapis.com/syzbot-assets/79a541b03a9e/bzImage-dca922e0.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+a21650c1666eae7b2aae@syzkaller.appspotmail.com > > BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:323 > in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5665, name: dhcpcd-run-hook > preempt_count: 0, expected: 0 > RCU nest depth: 1, expected: 0 > 2 locks held by dhcpcd-run-hook/5665: > #0: ffff8880243d01c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310 > #1: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] > #1: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] > #1: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290 > CPU: 0 UID: 0 PID: 5665 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full) > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 > Call Trace: > > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 > __might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9162 > might_alloc include/linux/sched/mm.h:323 [inline] > prepare_alloc_pages+0x44a/0x5f0 mm/page_alloc.c:4995 > __alloc_frozen_pages_noprof+0x19a/0x2bc0 mm/page_alloc.c:5215 > alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490 > folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509 > vma_alloc_folio_noprof+0xed/0x1d0 mm/mempolicy.c:2544 > folio_prealloc mm/memory.c:1193 [inline] > wp_page_copy mm/memory.c:3859 [inline] > do_wp_page+0x1ee1/0x4350 mm/memory.c:4320 Given pte_unmap_unlock() [1] before wp_page_copy(), the lockdep record of rcu lock above looks false positive. Baffled. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/memory.c#n4315 > handle_pte_fault mm/memory.c:6427 [inline] > __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549 > handle_mm_fault+0x36d/0xa20 mm/memory.c:6718 > do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334 > handle_page_fault arch/x86/mm/fault.c:1474 [inline] > exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 > RIP: 0033:0x7f5a6f60980e > Code: df e8 d7 c4 ff ff 48 8d 3d 9c 92 05 00 31 c0 e8 e1 ca ff ff 95 75 24 48 8d 05 5e 9c 07 00 44 89 f2 4c 89 e6 48 89 df 48 8b 00 <83> a0 f8 02 00 00 00 e8 de eb ff ff e9 a8 00 00 00 48 85 db 0f 84 > RSP: 002b:00007ffc0b5c63f0 EFLAGS: 00010246 > RAX: 000055c4ea134910 RBX: 000055c4ea135c60 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 000055c4ea138c30 RDI: 000055c4ea135c60 > RBP: 0000000000000000 R08: 00007f5a6f5b4b60 R09: 0000000000000000 > R10: 0000000000000008 R11: 0000000000000246 R12: 000055c4ea138c30 > R13: 000055c4ea135c60 R14: 0000000000000000 R15: 0000000000000000 > > > ================================================ > WARNING: lock held when returning to user space! > syzkaller #0 Tainted: G W > ------------------------------------------------ > dhcpcd-run-hook/5665 is leaving the kernel with locks still held! > 1 lock held by dhcpcd-run-hook/5665: > #0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] > #0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] > #0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup