From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49BKRHNzCVqXmXQxrfkG8P6jUCuRgBqj7UG9U+egVjE1IBiE3IaTtoHLMpcpeNF6BrzsXTr ARC-Seal: i=1; a=rsa-sha256; t=1524406224; cv=none; d=google.com; s=arc-20160816; b=HiGpAjxHOtlfktAV8oWkL3NkRPgCT1OZNyyZ+kfc5D/aVmJrPhOOYqrhPOC9G5PAd9 h2VM23feTzBsh8W7va166KsR1L4n6ipu4MUGN/o/I5/cgAZmpOmMh9IkDgayPq4r+UFh p270Tw1cwx1ftp78wJM2jjINuWAWj0g/udA8jqZqzfh4s+kB8ijlOe4UTu/sy5LN8PSV +V01obnjOnr0iDNXYN8C5K9+graGHHloDMRDoR2avOXQOlQpbpnN/Tm6TUmgKiMiEZqu 2yWUZRr7QCteWvKcG5/H4hwnWrRPsDgtOQXylkieXNeRVfuh8Q8J1I1malmOVD3/pWbE NCww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=Zm2rSTgv0UsdoQywxVQxEe0+RZP5GP6L3dl6y7d6q+g=; b=ixpibNLxt7SSsW8Dc3vosjXs9QGljIfUoZkLmDF86UsNvtDhIWXtqOKMs77saLC+Zd AIi4EqeWwMJ/AR4gBlJnmxOQlFdqmZH/o6w8kKhaBLb29ELkDisFJ109U+mj7eNCW4e+ iJ9Ui9np4E56qTzbnU1uUaLWKfjocYWiYWSnpZUuDHyWrjVQkE9jRJbdQQ2XqTqmQwJl 3Fq39ocoKWqOYi//NdpIKAkSkDtAM7o3e1wY19FU4LMGMMRKcoGzIFKEgopU3iPXuTyL tU3fZ5zKSgFxjoPGP3TLkifVkLHaHV9wGck8ClwNqWpfSUcvBXOrZAFvaCl/4/QJjXIg 76lg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthew Wilcox , Chris Fries , Johannes Weiner , Michal Hocko , Jan Kara , Andrew Morton , Linus Torvalds Subject: [PATCH 4.14 158/164] mm/filemap.c: fix NULL pointer in page_cache_tree_insert() Date: Sun, 22 Apr 2018 15:53:45 +0200 Message-Id: <20180422135142.066736920@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180422135135.400265110@linuxfoundation.org> References: <20180422135135.400265110@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598455322200106051?= X-GMAIL-MSGID: =?utf-8?q?1598455780988519164?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthew Wilcox commit abc1be13fd113ddef5e2d807a466286b864caed3 upstream. f2fs specifies the __GFP_ZERO flag for allocating some of its pages. Unfortunately, the page cache also uses the mapping's GFP flags for allocating radix tree nodes. It always masked off the __GFP_HIGHMEM flag, and masks off __GFP_ZERO in some paths, but not all. That causes radix tree nodes to be allocated with a NULL list_head, which causes backtraces like: __list_del_entry+0x30/0xd0 list_lru_del+0xac/0x1ac page_cache_tree_insert+0xd8/0x110 The __GFP_DMA and __GFP_DMA32 flags would also be able to sneak through if they are ever used. Fix them all by using GFP_RECLAIM_MASK at the innermost location, and remove it from earlier in the callchain. Link: http://lkml.kernel.org/r/20180411060320.14458-2-willy@infradead.org Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check") Signed-off-by: Matthew Wilcox Reported-by: Chris Fries Debugged-by: Minchan Kim Acked-by: Johannes Weiner Acked-by: Michal Hocko Reviewed-by: Jan Kara Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/filemap.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/mm/filemap.c +++ b/mm/filemap.c @@ -688,7 +688,7 @@ int replace_page_cache_page(struct page VM_BUG_ON_PAGE(!PageLocked(new), new); VM_BUG_ON_PAGE(new->mapping, new); - error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM); + error = radix_tree_preload(gfp_mask & GFP_RECLAIM_MASK); if (!error) { struct address_space *mapping = old->mapping; void (*freepage)(struct page *); @@ -744,7 +744,7 @@ static int __add_to_page_cache_locked(st return error; } - error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM); + error = radix_tree_maybe_preload(gfp_mask & GFP_RECLAIM_MASK); if (error) { if (!huge) mem_cgroup_cancel_charge(page, memcg, false); @@ -1486,8 +1486,7 @@ no_page: if (fgp_flags & FGP_ACCESSED) __SetPageReferenced(page); - err = add_to_page_cache_lru(page, mapping, offset, - gfp_mask & GFP_RECLAIM_MASK); + err = add_to_page_cache_lru(page, mapping, offset, gfp_mask); if (unlikely(err)) { put_page(page); page = NULL; @@ -2275,7 +2274,7 @@ static int page_cache_read(struct file * if (!page) return -ENOMEM; - ret = add_to_page_cache_lru(page, mapping, offset, gfp_mask & GFP_KERNEL); + ret = add_to_page_cache_lru(page, mapping, offset, gfp_mask); if (ret == 0) ret = mapping->a_ops->readpage(file, page); else if (ret == -EEXIST)