From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 81F103B5302 for ; Mon, 27 Apr 2026 16:44:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777308252; cv=none; b=ss/Y/nc+uHq9qL6ze7v3cvjvrx0ugudg0mJY++zrDL/uFmH2l1p85EBFEUroFZOpl7eil/3JrEWvE45lwTHJNt0f6GNJ2BmpowEaIhWNjWn5xI7rlwD/ldcwszm+pNB6VdzJMZkn+157Kl5SNDbj8uB0YFDCWckkNNjUwcrBciA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777308252; c=relaxed/simple; bh=6Km+6ELH/37oC3PihKKjj/bYAwytE395EQdIE20WDQ8=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=ERqZwOJjfu2iJREkM2lxgXip2kMyo6n/C6rcw9mPf2RX/zggkYOcjDswvaETFEXyXBt89Yu/rU+9dKOeDxmE2o4wNiqywVVfbb4y8ELMkfx99prJJdVns9nDxgt8lIPZJHRxzGxRwt8mqXPInj3w8tcEQhokkFPUoUakvqgBACI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BntQ2msB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BntQ2msB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03085C19425; Mon, 27 Apr 2026 16:44:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777308252; bh=6Km+6ELH/37oC3PihKKjj/bYAwytE395EQdIE20WDQ8=; h=Subject:To:Cc:From:Date:From; b=BntQ2msBVZKEDd8pxPoQTxVcuJB+XE41iD13KBthEgRtvWD6yW1J22m14Tf8OPMbf N/4MkhuyIPdHro6P8jBAqfb/Hvb30sPr/NCzSTavC7e4X3wu2rGM9U5clG2vTTExfP SafD+9tNmtFGGS6kPHIQb7itYa/+FlpFmtSwQigw= Subject: FAILED: patch "[PATCH] mm: prevent droppable mappings from being locked" failed to apply to 6.18-stable tree To: anthony.yznaga@oracle.com,akpm@linux-foundation.org,david@kernel.org,jannh@google.com,jason@zx2c4.com,liam.howlett@oracle.com,ljs@kernel.org,mhocko@suse.com,pfalcato@suse.de,rppt@kernel.org,shuah@kernel.org,stable@vger.kernel.org,surenb@google.com,vbabka@kernel.org Cc: From: Date: Mon, 27 Apr 2026 10:43:36 -0600 Message-ID: <2026042736-cheek-entree-3635@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x d239462787b072c78eb19fc1f155c3d411256282 # git commit -s git send-email --to '' --in-reply-to '2026042736-cheek-entree-3635@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From d239462787b072c78eb19fc1f155c3d411256282 Mon Sep 17 00:00:00 2001 From: Anthony Yznaga Date: Tue, 10 Mar 2026 08:58:20 -0700 Subject: [PATCH] mm: prevent droppable mappings from being locked Droppable mappings must not be lockable. There is a check for VMAs with VM_DROPPABLE set in mlock_fixup() along with checks for other types of unlockable VMAs which ensures this when calling mlock()/mlock2(). For mlockall(MCL_FUTURE), the check for unlockable VMAs is different. In apply_mlockall_flags(), if the flags parameter has MCL_FUTURE set, the current task's mm's default VMA flag field mm->def_flags has VM_LOCKED applied to it. VM_LOCKONFAULT is also applied if MCL_ONFAULT is also set. When these flags are set as default in this manner they are cleared in __mmap_complete() for new mappings that do not support mlock. A check for VM_DROPPABLE in __mmap_complete() is missing resulting in droppable mappings created with VM_LOCKED set. To fix this and reduce that chance of similar bugs in the future, introduce and use vma_supports_mlock(). Link: https://lkml.kernel.org/r/20260310155821.17869-1-anthony.yznaga@oracle.com Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings") Signed-off-by: Anthony Yznaga Suggested-by: David Hildenbrand Acked-by: David Hildenbrand (Arm) Reviewed-by: Pedro Falcato Reviewed-by: Lorenzo Stoakes (Oracle) Tested-by: Lorenzo Stoakes (Oracle) Cc: Jann Horn Cc: Jason A. Donenfeld Cc: Liam Howlett Cc: Michal Hocko Cc: Mike Rapoport Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton diff --git a/include/linux/hugetlb_inline.h b/include/linux/hugetlb_inline.h index 84afc3c3e2e4..565b473fd135 100644 --- a/include/linux/hugetlb_inline.h +++ b/include/linux/hugetlb_inline.h @@ -30,7 +30,7 @@ static inline bool is_vma_hugetlb_flags(const vma_flags_t *flags) #endif -static inline bool is_vm_hugetlb_page(struct vm_area_struct *vma) +static inline bool is_vm_hugetlb_page(const struct vm_area_struct *vma) { return is_vm_hugetlb_flags(vma->vm_flags); } diff --git a/mm/internal.h b/mm/internal.h index 4ab833b8bcdf..ebb68ad10d5c 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1243,6 +1243,16 @@ static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, } return fpin; } + +static inline bool vma_supports_mlock(const struct vm_area_struct *vma) +{ + if (vma->vm_flags & (VM_SPECIAL | VM_DROPPABLE)) + return false; + if (vma_is_dax(vma) || is_vm_hugetlb_page(vma)) + return false; + return vma != get_gate_vma(current->mm); +} + #else /* !CONFIG_MMU */ static inline void unmap_mapping_folio(struct folio *folio) { } static inline void mlock_new_folio(struct folio *folio) { } diff --git a/mm/mlock.c b/mm/mlock.c index 1a92d16f3684..fd648138bc72 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -472,10 +472,12 @@ static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma, int ret = 0; vm_flags_t oldflags = vma->vm_flags; - if (newflags == oldflags || (oldflags & VM_SPECIAL) || - is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) || - vma_is_dax(vma) || vma_is_secretmem(vma) || (oldflags & VM_DROPPABLE)) - /* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */ + if (newflags == oldflags || vma_is_secretmem(vma) || + !vma_supports_mlock(vma)) + /* + * Don't set VM_LOCKED or VM_LOCKONFAULT and don't count. + * For secretmem, don't allow the memory to be unlocked. + */ goto out; vma = vma_modify_flags(vmi, *prev, vma, start, end, &newflags); diff --git a/mm/vma.c b/mm/vma.c index e95fd5a5fe5c..b7055c264b5d 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -2589,9 +2589,7 @@ static void __mmap_complete(struct mmap_state *map, struct vm_area_struct *vma) vm_stat_account(mm, vma->vm_flags, map->pglen); if (vm_flags & VM_LOCKED) { - if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) || - is_vm_hugetlb_page(vma) || - vma == get_gate_vma(mm)) + if (!vma_supports_mlock(vma)) vm_flags_clear(vma, VM_LOCKED_MASK); else mm->locked_vm += map->pglen; diff --git a/tools/testing/vma/include/stubs.h b/tools/testing/vma/include/stubs.h index 947a3a0c2566..416bb93f5005 100644 --- a/tools/testing/vma/include/stubs.h +++ b/tools/testing/vma/include/stubs.h @@ -426,3 +426,8 @@ static inline void vma_adjust_trans_huge(struct vm_area_struct *vma, } static inline void hugetlb_split(struct vm_area_struct *, unsigned long) {} + +static inline bool vma_supports_mlock(const struct vm_area_struct *vma) +{ + return false; +}