From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 63DB834389F; Sat, 30 May 2026 17:42:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162949; cv=none; b=r7nU19n48fDlhhq+VfiU8iuQLEj5gao5dMgBR9hwfThwHK9URfXqNujaRoF/7gKfuL4QL+PLB2oVSadoUvEUCugd3y3KSuyBVK/dUw7JaNkG9VAyONpYmKx0i1In2bxSoLBKU0wB7XenWuAdjGP/deOCFGjeeoIVpUnOV3B09jE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162949; c=relaxed/simple; bh=GhT9UV3vp/zveAKJmrG01zZR1DJlDxGLQtd2cJ3PQdk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ipnXfLfo/k0Bt+BX7HwTagPaEmrs3gSOvrWMd70L8VkPp9tvOAnDVRZ+Ui/fa9981kjniIsQkjiXiq0IyoEulPSC+GDsqAhcvtwL29PzSuDCUjmZ6UBmQZXTR+jo1pVcuAipW5igKRe3yoDbIhUPKZHHYjbnXM2SnHLSvV/su/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eHxXnik8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="eHxXnik8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 292051F00893; Sat, 30 May 2026 17:42:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780162948; bh=1nUKMAOcliiN+avdirfNxpCuNr8TW3g4ttKwMpveLxE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eHxXnik8P7pUad5jmCWdlIsELwGUfKxa+YMmfdJaCcLhwA26M2uGAUgdx0EDiwuT9 2qqBQx2vfDSHvm0rp/fjNmB0g3fLoxGetv6lzVfFPUt8b7AByIhHAbeSOW5vtegqe6 9NtTG4hHCs1pjO5VwPcVLxIonaocmMc4w369yPz0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tejas Bharambe , syzbot+a49010a0e8fcdeea075f@syzkaller.appspotmail.com, Joseph Qi , Mark Fasheh , Joel Becker , Junxiao Bi , Changwei Ge , Jun Piao , Heming Zhao , Andrew Morton Subject: [PATCH 5.15 072/776] ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY Date: Sat, 30 May 2026 17:56:26 +0200 Message-ID: <20260530160242.182401911@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tejas Bharambe commit 7de554cabf160e331e4442e2a9ad874ca9875921 upstream. filemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY, as documented in mm/filemap.c: "If our return value has VM_FAULT_RETRY set, it's because the mmap_lock may be dropped before doing I/O or by lock_folio_maybe_drop_mmap()." When this happens, a concurrent munmap() can call remove_vma() and free the vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then becomes a dangling pointer, and the subsequent trace_ocfs2_fault() call dereferences it -- a use-after-free. Fix this by saving ip_blkno as a plain integer before calling filemap_fault(), and removing vma from the trace event. Since ip_blkno is copied by value before the lock can be dropped, it remains valid regardless of what happens to the vma or inode afterward. Link: https://lkml.kernel.org/r/20260410083816.34951-1-tejas.bharambe@outlook.com Fixes: 614a9e849ca6 ("ocfs2: Remove FILE_IO from masklog.") Signed-off-by: Tejas Bharambe Reported-by: syzbot+a49010a0e8fcdeea075f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=a49010a0e8fcdeea075f Suggested-by: Joseph Qi Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Heming Zhao Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/mmap.c | 7 +++---- fs/ocfs2/ocfs2_trace.h | 10 ++++------ 2 files changed, 7 insertions(+), 10 deletions(-) --- a/fs/ocfs2/mmap.c +++ b/fs/ocfs2/mmap.c @@ -30,7 +30,8 @@ static vm_fault_t ocfs2_fault(struct vm_fault *vmf) { - struct vm_area_struct *vma = vmf->vma; + unsigned long long ip_blkno = + OCFS2_I(file_inode(vmf->vma->vm_file))->ip_blkno; sigset_t oldset; vm_fault_t ret; @@ -38,11 +39,9 @@ static vm_fault_t ocfs2_fault(struct vm_ ret = filemap_fault(vmf); ocfs2_unblock_signals(&oldset); - trace_ocfs2_fault(OCFS2_I(vma->vm_file->f_mapping->host)->ip_blkno, - vma, vmf->page, vmf->pgoff); + trace_ocfs2_fault(ip_blkno, vmf->page, vmf->pgoff); return ret; } - static vm_fault_t __ocfs2_page_mkwrite(struct file *file, struct buffer_head *di_bh, struct page *page) { --- a/fs/ocfs2/ocfs2_trace.h +++ b/fs/ocfs2/ocfs2_trace.h @@ -1248,22 +1248,20 @@ TRACE_EVENT(ocfs2_write_end_inline, TRACE_EVENT(ocfs2_fault, TP_PROTO(unsigned long long ino, - void *area, void *page, unsigned long pgoff), - TP_ARGS(ino, area, page, pgoff), + void *page, unsigned long pgoff), + TP_ARGS(ino, page, pgoff), TP_STRUCT__entry( __field(unsigned long long, ino) - __field(void *, area) __field(void *, page) __field(unsigned long, pgoff) ), TP_fast_assign( __entry->ino = ino; - __entry->area = area; __entry->page = page; __entry->pgoff = pgoff; ), - TP_printk("%llu %p %p %lu", - __entry->ino, __entry->area, __entry->page, __entry->pgoff) + TP_printk("%llu %p %lu", + __entry->ino, __entry->page, __entry->pgoff) ); /* End of trace events for fs/ocfs2/mmap.c. */