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 D6AB915C15C for ; Mon, 11 Nov 2024 11:38:16 +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=1731325096; cv=none; b=J9sD1OkGr+fhX7sI697tzhQMLp8hrkB6O6ZeRfh7WyYc0vul+/Z27SqrLa23f5ErUAb3yf85ceUFOJJ4CZnq4htWxyB+FZ11CZqFIVspjKZ0ypJFR3n/gl/Xmuk0w+9pbA5QPSwV+PEpj3dZ4tJ0r0y0p08P2wyJq1Q/JNvJZ4s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731325096; c=relaxed/simple; bh=+D8yvyngtvFS7Lib2gNP31FovR5WOQvMcxgSPP0fjMo=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=Qv1u93rjN9LTAYJifTzlDJqgj3pmGbRUdKVApFdYHamPouZaN35CbEt1bcUgLpAbEozlJ3swk2jnrZzPI7InGzZ67EMr+XTG6XmWFx3wRnmGgtLfWbh0W8326ohPSUHnhyg80Qn1R7S4Qf5XrvoFvlSeAzt5SUZk/520VGTNOR0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Yxz/PHa/; 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="Yxz/PHa/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01548C4CECF; Mon, 11 Nov 2024 11:38:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1731325096; bh=+D8yvyngtvFS7Lib2gNP31FovR5WOQvMcxgSPP0fjMo=; h=Subject:To:Cc:From:Date:From; b=Yxz/PHa/xPgCfxvo/xCNwNk012PQIS2F4Wu3H3W9hYt1J5eqNK+7oS9w+KLLA/3fm EeAOAXJnbmNYBRCbQIG/Rpmja4wGK3WwB3Yy8RLGHxAfY0sG1QO0I5EvWHSvwR+Nh2 kYW41ZIMe2q+0ByK2Z1FYZkMFD05QE0hKJ3XzRdA= Subject: FAILED: patch "[PATCH] mm: unconditionally close VMAs on error" failed to apply to 5.10-stable tree To: lorenzo.stoakes@oracle.com,James.Bottomley@HansenPartnership.com,Liam.Howlett@oracle.com,akpm@linux-foundation.org,andreas@gaisler.com,broonie@kernel.org,catalin.marinas@arm.com,davem@davemloft.net,deller@gmx.de,jannh@google.com,peterx@redhat.com,stable@vger.kernel.org,torvalds@linux-foundation.org,vbabka@suse.cz,will@kernel.org Cc: From: Date: Mon, 11 Nov 2024 12:37:58 +0100 Message-ID: <2024111157-muster-engaging-dad6@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 5.10-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-5.10.y git checkout FETCH_HEAD git cherry-pick -x 4080ef1579b2413435413988d14ac8c68e4d42c8 # git commit -s git send-email --to '' --in-reply-to '2024111157-muster-engaging-dad6@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 4080ef1579b2413435413988d14ac8c68e4d42c8 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Tue, 29 Oct 2024 18:11:45 +0000 Subject: [PATCH] mm: unconditionally close VMAs on error Incorrect invocation of VMA callbacks when the VMA is no longer in a consistent state is bug prone and risky to perform. With regards to the important vm_ops->close() callback We have gone to great lengths to try to track whether or not we ought to close VMAs. Rather than doing so and risking making a mistake somewhere, instead unconditionally close and reset vma->vm_ops to an empty dummy operations set with a NULL .close operator. We introduce a new function to do so - vma_close() - and simplify existing vms logic which tracked whether we needed to close or not. This simplifies the logic, avoids incorrect double-calling of the .close() callback and allows us to update error paths to simply call vma_close() unconditionally - making VMA closure idempotent. Link: https://lkml.kernel.org/r/28e89dda96f68c505cb6f8e9fc9b57c3e9f74b42.1730224667.git.lorenzo.stoakes@oracle.com Fixes: deb0f6562884 ("mm/mmap: undo ->mmap() when arch_validate_flags() fails") Signed-off-by: Lorenzo Stoakes Reported-by: Jann Horn Reviewed-by: Vlastimil Babka Reviewed-by: Liam R. Howlett Reviewed-by: Jann Horn Cc: Andreas Larsson Cc: Catalin Marinas Cc: David S. Miller Cc: Helge Deller Cc: James E.J. Bottomley Cc: Linus Torvalds Cc: Mark Brown Cc: Peter Xu Cc: Will Deacon Cc: Signed-off-by: Andrew Morton diff --git a/mm/internal.h b/mm/internal.h index 4eab2961e69c..64c2eb0b160e 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -135,6 +135,24 @@ static inline int mmap_file(struct file *file, struct vm_area_struct *vma) return err; } +/* + * If the VMA has a close hook then close it, and since closing it might leave + * it in an inconsistent state which makes the use of any hooks suspect, clear + * them down by installing dummy empty hooks. + */ +static inline void vma_close(struct vm_area_struct *vma) +{ + if (vma->vm_ops && vma->vm_ops->close) { + vma->vm_ops->close(vma); + + /* + * The mapping is in an inconsistent state, and no further hooks + * may be invoked upon it. + */ + vma->vm_ops = &vma_dummy_vm_ops; + } +} + #ifdef CONFIG_MMU /* Flags for folio_pte_batch(). */ diff --git a/mm/mmap.c b/mm/mmap.c index 6e3b25f7728f..ac0604f146f6 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1573,8 +1573,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, return addr; close_and_free_vma: - if (file && !vms.closed_vm_ops && vma->vm_ops && vma->vm_ops->close) - vma->vm_ops->close(vma); + vma_close(vma); if (file || vma->vm_file) { unmap_and_free_vma: @@ -1934,7 +1933,7 @@ void exit_mmap(struct mm_struct *mm) do { if (vma->vm_flags & VM_ACCOUNT) nr_accounted += vma_pages(vma); - remove_vma(vma, /* unreachable = */ true, /* closed = */ false); + remove_vma(vma, /* unreachable = */ true); count++; cond_resched(); vma = vma_next(&vmi); diff --git a/mm/nommu.c b/mm/nommu.c index f9ccc02458ec..635d028d647b 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -589,8 +589,7 @@ static int delete_vma_from_mm(struct vm_area_struct *vma) */ static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) { - if (vma->vm_ops && vma->vm_ops->close) - vma->vm_ops->close(vma); + vma_close(vma); if (vma->vm_file) fput(vma->vm_file); put_nommu_region(vma->vm_region); diff --git a/mm/vma.c b/mm/vma.c index b21ffec33f8e..7621384d64cf 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -323,11 +323,10 @@ static bool can_vma_merge_right(struct vma_merge_struct *vmg, /* * Close a vm structure and free it. */ -void remove_vma(struct vm_area_struct *vma, bool unreachable, bool closed) +void remove_vma(struct vm_area_struct *vma, bool unreachable) { might_sleep(); - if (!closed && vma->vm_ops && vma->vm_ops->close) - vma->vm_ops->close(vma); + vma_close(vma); if (vma->vm_file) fput(vma->vm_file); mpol_put(vma_policy(vma)); @@ -1115,9 +1114,7 @@ void vms_clean_up_area(struct vma_munmap_struct *vms, vms_clear_ptes(vms, mas_detach, true); mas_set(mas_detach, 0); mas_for_each(mas_detach, vma, ULONG_MAX) - if (vma->vm_ops && vma->vm_ops->close) - vma->vm_ops->close(vma); - vms->closed_vm_ops = true; + vma_close(vma); } /* @@ -1160,7 +1157,7 @@ void vms_complete_munmap_vmas(struct vma_munmap_struct *vms, /* Remove and clean up vmas */ mas_set(mas_detach, 0); mas_for_each(mas_detach, vma, ULONG_MAX) - remove_vma(vma, /* = */ false, vms->closed_vm_ops); + remove_vma(vma, /* unreachable = */ false); vm_unacct_memory(vms->nr_accounted); validate_mm(mm); @@ -1684,8 +1681,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, return new_vma; out_vma_link: - if (new_vma->vm_ops && new_vma->vm_ops->close) - new_vma->vm_ops->close(new_vma); + vma_close(new_vma); if (new_vma->vm_file) fput(new_vma->vm_file); diff --git a/mm/vma.h b/mm/vma.h index 55457cb68200..75558b5e9c8c 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -42,7 +42,6 @@ struct vma_munmap_struct { int vma_count; /* Number of vmas that will be removed */ bool unlock; /* Unlock after the munmap */ bool clear_ptes; /* If there are outstanding PTE to be cleared */ - bool closed_vm_ops; /* call_mmap() was encountered, so vmas may be closed */ /* 1 byte hole */ unsigned long nr_pages; /* Number of pages being removed */ unsigned long locked_vm; /* Number of locked pages */ @@ -198,7 +197,6 @@ static inline void init_vma_munmap(struct vma_munmap_struct *vms, vms->unmap_start = FIRST_USER_ADDRESS; vms->unmap_end = USER_PGTABLES_CEILING; vms->clear_ptes = false; - vms->closed_vm_ops = false; } #endif @@ -269,7 +267,7 @@ int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf, bool unlock); -void remove_vma(struct vm_area_struct *vma, bool unreachable, bool closed); +void remove_vma(struct vm_area_struct *vma, bool unreachable); void unmap_region(struct ma_state *mas, struct vm_area_struct *vma, struct vm_area_struct *prev, struct vm_area_struct *next);