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 F39D3149E0A; Tue, 25 Jun 2024 09:53:23 +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=1719309204; cv=none; b=MkdGcphUfLIrVS+jyjDvi1Ys4AdhBI2W1WSh8oCiQJjsP928o4K36JBJy67JOmlJCPU8ElREhcZ1j0YuJRq/inNjNwG5dGuaOHI8UMGOOu+XhWX8sFOxNSFGyjnbdjs02jUZa0kbk30FKWAt93ac8KyyN7fIu+krtlp11Sh3O3I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719309204; c=relaxed/simple; bh=pn28iGsCjxZC/Dt/+IWK5u8XuOfgJbf3NerOBDxpqas=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PtQUu8gYiegiFnIfWty+3vQAPy1zU1ekp3MEQmVadrYMCZxPt1th9fVQPrTQ5axhI2foqTOBtbVISr3HQjGmWGLU0AP0RmDAfnpgmVQZ1HnCyKEYa4AWg4sc4o+99ThY2Dg2fB+bLxkVMvfUYG/Z1QjgP1ehclQnBR/iqDGpTcs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UNDgtzNd; 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="UNDgtzNd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 733BAC32781; Tue, 25 Jun 2024 09:53:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1719309203; bh=pn28iGsCjxZC/Dt/+IWK5u8XuOfgJbf3NerOBDxpqas=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UNDgtzNdJjHS0ZyHgeGeis5MU7R6j1BL4rGhjCbEcjNlprekrJS0glWE2GOLzeuGi FmveIht9HvNOOWCJ5AdHVPod8fCNn98RM5osodw/EBdWq71gE+VXiaeqoXoyGwenq2 SmjIX2JibPJ2nONFMLQJJvqpaUyCVNf+l1R3og+s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Baokun Li , Jan Kara , Ojaswin Mujoo , Theodore Tso Subject: [PATCH 6.6 131/192] ext4: fix slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists() Date: Tue, 25 Jun 2024 11:33:23 +0200 Message-ID: <20240625085542.189183696@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240625085537.150087723@linuxfoundation.org> References: <20240625085537.150087723@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li commit 13df4d44a3aaabe61cd01d277b6ee23ead2a5206 upstream. We can trigger a slab-out-of-bounds with the following commands: mkfs.ext4 -F /dev/$disk 10G mount /dev/$disk /tmp/test echo 2147483647 > /sys/fs/ext4/$disk/mb_group_prealloc echo test > /tmp/test/file && sync ================================================================== BUG: KASAN: slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4] Read of size 8 at addr ffff888121b9d0f0 by task kworker/u2:0/11 CPU: 0 PID: 11 Comm: kworker/u2:0 Tainted: GL 6.7.0-next-20240118 #521 Call Trace: dump_stack_lvl+0x2c/0x50 kasan_report+0xb6/0xf0 ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4] ext4_mb_regular_allocator+0x19e9/0x2370 [ext4] ext4_mb_new_blocks+0x88a/0x1370 [ext4] ext4_ext_map_blocks+0x14f7/0x2390 [ext4] ext4_map_blocks+0x569/0xea0 [ext4] ext4_do_writepages+0x10f6/0x1bc0 [ext4] [...] ================================================================== The flow of issue triggering is as follows: // Set s_mb_group_prealloc to 2147483647 via sysfs ext4_mb_new_blocks ext4_mb_normalize_request ext4_mb_normalize_group_request ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc ext4_mb_regular_allocator ext4_mb_choose_next_group ext4_mb_choose_next_group_best_avail mb_avg_fragment_size_order order = fls(len) - 2 = 29 ext4_mb_find_good_group_avg_frag_lists frag_list = &sbi->s_mb_avg_fragment_size[order] if (list_empty(frag_list)) // Trigger SOOB! At 4k block size, the length of the s_mb_avg_fragment_size list is 14, but an oversized s_mb_group_prealloc is set, causing slab-out-of-bounds to be triggered by an attempt to access an element at index 29. Add a new attr_id attr_clusters_in_group with values in the range [0, sbi->s_clusters_per_group] and declare mb_group_prealloc as that type to fix the issue. In addition avoid returning an order from mb_avg_fragment_size_order() greater than MB_NUM_ORDERS(sb) and reduce some useless loops. Fixes: 7e170922f06b ("ext4: Add allocation criteria 1.5 (CR1_5)") CC: stable@vger.kernel.org Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/20240319113325.3110393-5-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 4 ++++ fs/ext4/sysfs.c | 13 ++++++++++++- 2 files changed, 16 insertions(+), 1 deletion(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -831,6 +831,8 @@ static int mb_avg_fragment_size_order(st return 0; if (order == MB_NUM_ORDERS(sb)) order--; + if (WARN_ON_ONCE(order > MB_NUM_ORDERS(sb))) + order = MB_NUM_ORDERS(sb) - 1; return order; } @@ -1008,6 +1010,8 @@ static void ext4_mb_choose_next_group_be * goal length. */ order = fls(ac->ac_g_ex.fe_len) - 1; + if (WARN_ON_ONCE(order - 1 > MB_NUM_ORDERS(ac->ac_sb))) + order = MB_NUM_ORDERS(ac->ac_sb); min_order = order - sbi->s_mb_best_avail_max_trim_order; if (min_order < 0) min_order = 0; --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -29,6 +29,7 @@ typedef enum { attr_trigger_test_error, attr_first_error_time, attr_last_error_time, + attr_clusters_in_group, attr_feature, attr_pointer_ui, attr_pointer_ul, @@ -207,13 +208,14 @@ EXT4_ATTR_FUNC(sra_exceeded_retry_limit, EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead, ext4_sb_info, s_inode_readahead_blks); +EXT4_ATTR_OFFSET(mb_group_prealloc, 0644, clusters_in_group, + ext4_sb_info, s_mb_group_prealloc); EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal); EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats); EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan); EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan); EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs); EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request); -EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc); EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups); EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb); EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error); @@ -392,6 +394,7 @@ static ssize_t ext4_attr_show(struct kob (unsigned long long) percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit)); case attr_inode_readahead: + case attr_clusters_in_group: case attr_pointer_ui: if (!ptr) return 0; @@ -469,6 +472,14 @@ static ssize_t ext4_attr_store(struct ko else *((unsigned int *) ptr) = t; return len; + case attr_clusters_in_group: + ret = kstrtouint(skip_spaces(buf), 0, &t); + if (ret) + return ret; + if (t > sbi->s_clusters_per_group) + return -EINVAL; + *((unsigned int *) ptr) = t; + return len; case attr_pointer_ul: if (!ptr) return 0;