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 1D620C2E0; Mon, 23 Jun 2025 21:32:11 +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=1750714331; cv=none; b=GHM5I+IJIMnSrG2ZgHQSczc3rJUmlpQDxAzKCazhC3Yz2fzpNIufj0CTxHrI8O1Dj61RvYtvn1lLC3Vp+FIDhdYQhWUYAVrxX+EokEF+WADDu0e2V0LEdnp/6qm3Kt6/TzKNqPUmi8ax/G67AW4l8q9uKsrPjKpssmKp73Lxujs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750714331; c=relaxed/simple; bh=SnvfQi83TbvIuMDuFsQBdtW3qcikNuMdp6eAUDCHdJI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DZ0Q/RKzsEtcCKk0Y0gr5dq+RhQ9iN0BAWHGwQweKFsufBqUcDUoc1J+m9iZUCDFP0cB5DDggY58RYLWiFaJ2pYHF/DzSlKxtTQl7KHWyDrgUt7fVSM7wSrqi1OrPBqiuiVzGI05QRPz7i1V0kAy5HRt/4r+TLnr3hBO2e/4gH0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zANxTvMd; 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="zANxTvMd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A89D1C4CEEA; Mon, 23 Jun 2025 21:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750714331; bh=SnvfQi83TbvIuMDuFsQBdtW3qcikNuMdp6eAUDCHdJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zANxTvMdGZid/fVY1lt/xQJuwSoZtrLiy5VyMKHMBYPkWt5d67rV0eXXlnCTf3dZV bq9SchONfsBaeFwTsekt99iCTu+2Knkz7cN+7xGLVpdn0FjS4iapz1LLXW/eWkPVHy r2qv6CzvWlsV56jpR/CYTtE+WIH6LVFH3gYi5zJo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Brian Foster , Theodore Tso , Jan Kara , stable@kernel.org Subject: [PATCH 6.12 096/414] ext4: only dirty folios when data journaling regular files Date: Mon, 23 Jun 2025 15:03:53 +0200 Message-ID: <20250623130644.493710276@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250623130642.015559452@linuxfoundation.org> References: <20250623130642.015559452@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Brian Foster commit e26268ff1dcae5662c1b96c35f18cfa6ab73d9de upstream. fstest generic/388 occasionally reproduces a crash that looks as follows: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: ext4_block_zero_page_range+0x30c/0x380 [ext4] ext4_truncate+0x436/0x440 [ext4] ext4_process_orphan+0x5d/0x110 [ext4] ext4_orphan_cleanup+0x124/0x4f0 [ext4] ext4_fill_super+0x262d/0x3110 [ext4] get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x26/0xd0 vfs_cmd_create+0x59/0xe0 __do_sys_fsconfig+0x4ed/0x6b0 do_syscall_64+0x82/0x170 ... This occurs when processing a symlink inode from the orphan list. The partial block zeroing code in the truncate path calls ext4_dirty_journalled_data() -> folio_mark_dirty(). The latter calls mapping->a_ops->dirty_folio(), but symlink inodes are not assigned an a_ops vector in ext4, hence the crash. To avoid this problem, update the ext4_dirty_journalled_data() helper to only mark the folio dirty on regular files (for which a_ops is assigned). This also matches the journaling logic in the ext4_symlink() creation path, where ext4_handle_dirty_metadata() is called directly. Fixes: d84c9ebdac1e ("ext4: Mark pages with journalled data dirty") Signed-off-by: Brian Foster Link: https://patch.msgid.link/20250516173800.175577-1-bfoster@redhat.com Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1000,7 +1000,12 @@ int ext4_walk_page_buffers(handle_t *han */ static int ext4_dirty_journalled_data(handle_t *handle, struct buffer_head *bh) { - folio_mark_dirty(bh->b_folio); + struct folio *folio = bh->b_folio; + struct inode *inode = folio->mapping->host; + + /* only regular files have a_ops */ + if (S_ISREG(inode->i_mode)) + folio_mark_dirty(folio); return ext4_handle_dirty_metadata(handle, NULL, bh); }