The quilt patch titled Subject: mm/mempolicy: fix migrate_to_node() assuming there is at least one VMA in a MM has been removed from the -mm tree. Its filename was mm-mempolicy-fix-migrate_to_node-assuming-there-is-at-least-one-vma-in-a-mm.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------ From: David Hildenbrand david@redhat.com Subject: mm/mempolicy: fix migrate_to_node() assuming there is at least one VMA in a MM Date: Wed, 20 Nov 2024 21:11:51 +0100

We currently assume that there is at least one VMA in a MM, which isn't true.

So we might end up having find_vma() return NULL, to then de-reference NULL. So properly handle find_vma() returning NULL.

This fixes the report:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 6021 Comm: syz-executor284 Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:migrate_to_node mm/mempolicy.c:1090 [inline] RIP: 0010:do_migrate_pages+0x403/0x6f0 mm/mempolicy.c:1194 Code: ... RSP: 0018:ffffc9000375fd08 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffc9000375fd78 RCX: 0000000000000000 RDX: ffff88807e171300 RSI: dffffc0000000000 RDI: ffff88803390c044 RBP: ffff88807e171428 R08: 0000000000000014 R09: fffffbfff2039ef1 R10: ffffffff901cf78f R11: 0000000000000000 R12: 0000000000000003 R13: ffffc9000375fe90 R14: ffffc9000375fe98 R15: ffffc9000375fdf8 FS: 00005555919e1380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555919e1ca8 CR3: 000000007f12a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> kernel_migrate_pages+0x5b2/0x750 mm/mempolicy.c:1709 __do_sys_migrate_pages mm/mempolicy.c:1727 [inline] __se_sys_migrate_pages mm/mempolicy.c:1723 [inline] __x64_sys_migrate_pages+0x96/0x100 mm/mempolicy.c:1723 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

[akpm@linux-foundation.org: add unlikely()] Link: https://lkml.kernel.org/r/20241120201151.9518-1-david@redhat.com Fixes: 39743889aaf7 ("[PATCH] Swap Migration V5: sys_migrate_pages interface") Signed-off-by: David Hildenbrand david@redhat.com Reported-by: syzbot+3511625422f7aa637f0d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/673d2696.050a0220.3c9d61.012f.GAE@google.com/T/ Reviewed-by: Liam R. Howlett Liam.Howlett@Oracle.com Reviewed-by: Christoph Lameter cl@linux.com Cc: Liam R. Howlett Liam.Howlett@Oracle.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/mempolicy.c | 4 ++++ 1 file changed, 4 insertions(+)

--- a/mm/mempolicy.c~mm-mempolicy-fix-migrate_to_node-assuming-there-is-at-least-one-vma-in-a-mm +++ a/mm/mempolicy.c @@ -1080,6 +1080,10 @@ static long migrate_to_node(struct mm_st

mmap_read_lock(mm); vma = find_vma(mm, 0); + if (unlikely(!vma)) { + mmap_read_unlock(mm); + return 0; + }

/* * This does not migrate the range, but isolates all pages that _

Patches currently in -mm which might be from david@redhat.com are

docs-tmpfs-update-the-large-folios-policy-for-tmpfs-and-shmem.patch mm-memory_hotplug-move-debug_pagealloc_map_pages-into-online_pages_range.patch mm-page_isolation-dont-pass-gfp-flags-to-isolate_single_pageblock.patch mm-page_isolation-dont-pass-gfp-flags-to-start_isolate_page_range.patch mm-page_alloc-make-__alloc_contig_migrate_range-static.patch mm-page_alloc-sort-out-the-alloc_contig_range-gfp-flags-mess.patch mm-page_alloc-forward-the-gfp-flags-from-alloc_contig_range-to-post_alloc_hook.patch powernv-memtrace-use-__gfp_zero-with-alloc_contig_pages.patch mm-hugetlb-dont-map-folios-writable-without-vm_write-when-copying-during-fork.patch fs-proc-vmcore-convert-vmcore_cb_lock-into-vmcore_mutex.patch fs-proc-vmcore-replace-vmcoredd_mutex-by-vmcore_mutex.patch fs-proc-vmcore-disallow-vmcore-modifications-while-the-vmcore-is-open.patch fs-proc-vmcore-prefix-all-pr_-with-vmcore.patch fs-proc-vmcore-move-vmcore-definitions-out-of-kcoreh.patch fs-proc-vmcore-factor-out-allocating-a-vmcore-range-and-adding-it-to-a-list.patch fs-proc-vmcore-factor-out-freeing-a-list-of-vmcore-ranges.patch fs-proc-vmcore-introduce-proc_vmcore_device_ram-to-detect-device-ram-ranges-in-2nd-kernel.patch virtio-mem-mark-device-ready-before-registering-callbacks-in-kdump-mode.patch virtio-mem-remember-usable-region-size.patch virtio-mem-support-config_proc_vmcore_device_ram.patch s390-kdump-virtio-mem-kdump-support-config_proc_vmcore_device_ram.patch