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 188B23890F3 for ; Fri, 24 Apr 2026 09:38:45 +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=1777023526; cv=none; b=BH0N+uiQok7uokQiQfRHhBemCRg5Ffn6bi/937j5pE2c6PwXkPPW1AH6m9byKDUw7ZvVo0SNnbmfdhCBkmX1G/gLMal9igsw4+3SICQoPg+PWwCeXVb1h1ZujAObQntz3rSziUzcLZPt/2E7BWvOPfmaC0eCx96sC75MUoBY5bU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777023526; c=relaxed/simple; bh=+x8OkTfOBGx8Gh7MTJ20QCsyVgvhl68GvpLwNm7scO4=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=O/eFeuFIdHzIVUrH7NCNgJ4u2/n+w4ZMeDXJ8oH17z+6RUdG5ojvVLs0X7rxu6XSNkCBQ14oCORQd1o0njCKOgBYb24nssPWy8j144ydLPyynY39xrY/IPgR39k7tjD+m1GREXKxX+q9fShMq5UchxAlpSY0rBoybmN3o8Uc1SY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JTK/OvV1; 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="JTK/OvV1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61CEEC19425; Fri, 24 Apr 2026 09:38:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777023525; bh=+x8OkTfOBGx8Gh7MTJ20QCsyVgvhl68GvpLwNm7scO4=; h=Subject:To:Cc:From:Date:From; b=JTK/OvV1LriLnLhPD9u6/dVzVCeFrLmQP3G8/2oFFcgytH8dZkfiTO8jDBfdnBat9 sqSJ1YtUG/mPx7DTMtAC+O/wNh7D2A751BakevNeB3KjxinGr/Kwm04Qz9XRQ8iMwk 43pD1zgUM/SyMxds4JD6EBpsFIInEU5BV7I4XpGM= Subject: FAILED: patch "[PATCH] f2fs: fix UAF caused by decrementing sbi->nr_pages[] in" failed to apply to 5.15-stable tree To: yangyongpeng@xiaomi.com,chao@kernel.org,jaegeuk@kernel.org Cc: From: Date: Fri, 24 Apr 2026 11:38:35 +0200 Message-ID: <2026042434-undead-bronzing-dd24@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 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x 2d9c4a4ed4eef1f82c5b16b037aee8bad819fd53 # git commit -s git send-email --to '' --in-reply-to '2026042434-undead-bronzing-dd24@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 2d9c4a4ed4eef1f82c5b16b037aee8bad819fd53 Mon Sep 17 00:00:00 2001 From: Yongpeng Yang Date: Fri, 27 Feb 2026 15:30:52 +0800 Subject: [PATCH] f2fs: fix UAF caused by decrementing sbi->nr_pages[] in f2fs_write_end_io() The xfstests case "generic/107" and syzbot have both reported a NULL pointer dereference. The concurrent scenario that triggers the panic is as follows: F2FS_WB_CP_DATA write callback umount - f2fs_write_checkpoint - f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA) - blk_mq_end_request - bio_endio - f2fs_write_end_io : dec_page_count(sbi, F2FS_WB_CP_DATA) : wake_up(&sbi->cp_wait) - kill_f2fs_super - kill_block_super - f2fs_put_super : iput(sbi->node_inode) : sbi->node_inode = NULL : f2fs_in_warm_node_list - is_node_folio // sbi->node_inode is NULL and panic The root cause is that f2fs_put_super() calls iput(sbi->node_inode) and sets sbi->node_inode to NULL after sbi->nr_pages[F2FS_WB_CP_DATA] is decremented to zero. As a result, f2fs_in_warm_node_list() may dereference a NULL node_inode when checking whether a folio belongs to the node inode, leading to a panic. This patch fixes the issue by calling f2fs_in_warm_node_list() before decrementing sbi->nr_pages[F2FS_WB_CP_DATA], thus preventing the use-after-free condition. Cc: stable@kernel.org Fixes: 50fa53eccf9f ("f2fs: fix to avoid broken of dnode block list") Reported-by: syzbot+6e4cb1cac5efc96ea0ca@syzkaller.appspotmail.com Signed-off-by: Yongpeng Yang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 400f0400e13d..57fc9bad31bf 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -386,6 +386,8 @@ static void f2fs_write_end_io(struct bio *bio) folio->index, NODE_TYPE_REGULAR, true); f2fs_bug_on(sbi, folio->index != nid_of_node(folio)); } + if (f2fs_in_warm_node_list(sbi, folio)) + f2fs_del_fsync_node_entry(sbi, folio); dec_page_count(sbi, type); @@ -397,8 +399,6 @@ static void f2fs_write_end_io(struct bio *bio) wq_has_sleeper(&sbi->cp_wait)) wake_up(&sbi->cp_wait); - if (f2fs_in_warm_node_list(sbi, folio)) - f2fs_del_fsync_node_entry(sbi, folio); folio_clear_f2fs_gcing(folio); folio_end_writeback(folio); }