From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6CBA3362 for ; Fri, 16 Dec 2022 16:32:36 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 86A1A3454D; Fri, 16 Dec 2022 16:32:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1671208349; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ifpYR2PdESJAbvJefyXjW1EWj/1z2L0zImGtUVLVTog=; b=G0OuXHi/vYNbH57ZVsfKkJHhPgNpbk73CrPzwAWNhyKC3Xh8oDQOLuRGpTKYCaTgy2aXzB k0KaxX3xKjrzsD+IFm28RtsBbuoo+JfPz565cOawN8pNgSC13NF9g2u/aUaZ1t/RcOUdug Qo9E/fq7nu67Auoe/CaI7a2LO2TRDg8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1671208349; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ifpYR2PdESJAbvJefyXjW1EWj/1z2L0zImGtUVLVTog=; b=yah1WAubrE2ujAH04CMoJ6yYkHNQn4D1DQrpz87GR8v/vJCOlcD2/p8mCcKOkvRmP0v02E soZWIZ2/b5FHFHAA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 580D0138F0; Fri, 16 Dec 2022 16:32:29 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id /03PFJ2dnGOaKQAAMHmgww (envelope-from ); Fri, 16 Dec 2022 16:32:29 +0000 From: Vlastimil Babka To: Andrew Morton Cc: linux-mm@kvack.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, Vlastimil Babka , Jiri Slaby , =?UTF-8?q?Jakub=20Mat=C4=9Bna?= , stable@vger.kernel.org, "Kirill A . Shutemov" , Liam Howlett , Matthew Wilcox , Mel Gorman , Michal Hocko Subject: [PATCH for v6.1 regression] mm, mremap: fix mremap() expanding vma with addr inside vma Date: Fri, 16 Dec 2022 17:32:27 +0100 Message-Id: <20221216163227.24648-1-vbabka@suse.cz> X-Mailer: git-send-email 2.38.1 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since 6.1 we have noticed random rpm install failures that were tracked to mremap() returning -ENOMEM and to commit ca3d76b0aa80 ("mm: add merging after mremap resize"). The problem occurs when mremap() expands a VMA in place, but using an starting address that's not vma->vm_start, but somewhere in the middle. The extension_pgoff calculation introduced by the commit is wrong in that case, so vma_merge() fails due to pgoffs not being compatible. Fix the calculation. By the way it seems that the situations, where rpm now expands a vma from the middle, were made possible also due to that commit, thanks to the improved vma merging. Yet it should work just fine, except for the buggy calculation. Reported-by: Jiri Slaby Link: https://bugzilla.suse.com/show_bug.cgi?id=1206359 Fixes: ca3d76b0aa80 ("mm: add merging after mremap resize") Signed-off-by: Vlastimil Babka Cc: Jakub Matěna Cc: Cc: "Kirill A . Shutemov" Cc: Liam Howlett Cc: Matthew Wilcox Cc: Mel Gorman Cc: Michal Hocko --- Hi, this fixes a regression in 6.1 so please process ASAP so that stable 6.1.y can get the fix. mm/mremap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/mremap.c b/mm/mremap.c index e465ffe279bb..fe587c5d6591 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -1016,7 +1016,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, long pages = (new_len - old_len) >> PAGE_SHIFT; unsigned long extension_start = addr + old_len; unsigned long extension_end = addr + new_len; - pgoff_t extension_pgoff = vma->vm_pgoff + (old_len >> PAGE_SHIFT); + pgoff_t extension_pgoff = vma->vm_pgoff + + ((extension_start - vma->vm_start) >> PAGE_SHIFT); if (vma->vm_flags & VM_ACCOUNT) { if (security_vm_enough_memory_mm(mm, pages)) { -- 2.38.1