From 9a8c5b0d061554fedd7dbe894e63aa34d0bac7c4 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 27 Oct 2022 16:04:36 -0400 Subject: [PATCH 1/5] ext4: update the backup superblock's at the end of the online resize When expanding a file system using online resize, various fields in the superblock (e.g., s_blocks_count, s_inodes_count, etc.) change. To update the backup superblocks, the online resize uses the function update_backups() in fs/ext4/resize.c. This function was not updating the checksum field in the backup superblocks. This wasn't a big deal previously, because e2fsck didn't care about the checksum field in the backup superblock. (And indeed, update_backups() goes all the way back to the ext3 days, well before we had support for metadata checksums.) However, there is an alternate, more general way of updating superblock fields, ext4_update_primary_sb() in fs/ext4/ioctl.c. This function does check the checksum of the backup superblock, and if it doesn't match will mark the file system as corrupted. That was clearly not the intent, so avoid to aborting the resize when a bad superblock is found. In addition, teach update_backups() to properly update the checksum in the backup superblocks. We will eventually want to unify updapte_backups() with the infrasture in ext4_update_primary_sb(), but that's for another day. Note: The problem has been around for a while; it just didn't really matter until ext4_update_primary_sb() was added by commit bbc605cdb1e1 ("ext4: implement support for get/set fs label"). And it became trivially easy to reproduce after commit 827891a38acc ("ext4: update the s_overhead_clusters in the backup sb's when resizing") in v6.0. Cc: stable@kernel.org # 5.17+ Fixes: bbc605cdb1e1 ("ext4: implement support for get/set fs label") Signed-off-by: Theodore Ts'o --- fs/ext4/ioctl.c | 3 +-- fs/ext4/resize.c | 5 +++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 4d49c5cfb690..790d5ffe8559 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -145,9 +145,8 @@ static int ext4_update_backup_sb(struct super_block *sb, if (ext4_has_metadata_csum(sb) && es->s_checksum != ext4_superblock_csum(sb, es)) { ext4_msg(sb, KERN_ERR, "Invalid checksum for backup " - "superblock %llu\n", sb_block); + "superblock %llu", sb_block); unlock_buffer(bh); - err = -EFSBADCRC; goto out_bh; } func(es, arg); diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 6dfe9ccae0c5..46b87ffeb304 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1158,6 +1158,7 @@ static void update_backups(struct super_block *sb, sector_t blk_off, char *data, while (group < sbi->s_groups_count) { struct buffer_head *bh; ext4_fsblk_t backup_block; + struct ext4_super_block *es; /* Out of journal space, and can't get more - abort - so sad */ err = ext4_resize_ensure_credits_batch(handle, 1); @@ -1186,6 +1187,10 @@ static void update_backups(struct super_block *sb, sector_t blk_off, char *data, memcpy(bh->b_data, data, size); if (rest) memset(bh->b_data + size, 0, rest); + es = (struct ext4_super_block *) bh->b_data; + es->s_block_group_nr = cpu_to_le16(group); + if (ext4_has_metadata_csum(sb)) + es->s_checksum = ext4_superblock_csum(sb, es); set_buffer_uptodate(bh); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, NULL, bh); From 17a0bc9bd697f75cfdf9b378d5eb2d7409c91340 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lu=C3=ADs=20Henriques?= Date: Wed, 12 Oct 2022 14:13:30 +0100 Subject: [PATCH 2/5] ext4: fix BUG_ON() when directory entry has invalid rec_len MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The rec_len field in the directory entry has to be a multiple of 4. A corrupted filesystem image can be used to hit a BUG() in ext4_rec_len_to_disk(), called from make_indexed_dir(). ------------[ cut here ]------------ kernel BUG at fs/ext4/ext4.h:2413! ... RIP: 0010:make_indexed_dir+0x53f/0x5f0 ... Call Trace: ? add_dirent_to_buf+0x1b2/0x200 ext4_add_entry+0x36e/0x480 ext4_add_nondir+0x2b/0xc0 ext4_create+0x163/0x200 path_openat+0x635/0xe90 do_filp_open+0xb4/0x160 ? __create_object.isra.0+0x1de/0x3b0 ? _raw_spin_unlock+0x12/0x30 do_sys_openat2+0x91/0x150 __x64_sys_open+0x6c/0xa0 do_syscall_64+0x3c/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The fix simply adds a call to ext4_check_dir_entry() to validate the directory entry, returning -EFSCORRUPTED if the entry is invalid. CC: stable@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=216540 Signed-off-by: Luís Henriques Link: https://lore.kernel.org/r/20221012131330.32456-1-lhenriques@suse.de Signed-off-by: Theodore Ts'o --- fs/ext4/namei.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 4183a4cb4a21..be8136aafa22 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2259,8 +2259,16 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname, memset(de, 0, len); /* wipe old data */ de = (struct ext4_dir_entry_2 *) data2; top = data2 + len; - while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) + while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) { + if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len, + (data2 + (blocksize - csum_size) - + (char *) de))) { + brelse(bh2); + brelse(bh); + return -EFSCORRUPTED; + } de = de2; + } de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - (char *) de, blocksize); From 1b8f787ef547230a3249bcf897221ef0cc78481b Mon Sep 17 00:00:00 2001 From: Ye Bin Date: Tue, 18 Oct 2022 10:27:01 +0800 Subject: [PATCH 3/5] ext4: fix warning in 'ext4_da_release_space' Syzkaller report issue as follows: EXT4-fs (loop0): Free/Dirty block details EXT4-fs (loop0): free_blocks=0 EXT4-fs (loop0): dirty_blocks=0 EXT4-fs (loop0): Block reservation details EXT4-fs (loop0): i_reserved_data_blocks=0 EXT4-fs warning (device loop0): ext4_da_release_space:1527: ext4_da_release_space: ino 18, to_free 1 with only 0 reserved data blocks ------------[ cut here ]------------ WARNING: CPU: 0 PID: 92 at fs/ext4/inode.c:1528 ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1524 Modules linked in: CPU: 0 PID: 92 Comm: kworker/u4:4 Not tainted 6.0.0-syzkaller-09423-g493ffd6605b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1528 RSP: 0018:ffffc900015f6c90 EFLAGS: 00010296 RAX: 42215896cd52ea00 RBX: 0000000000000000 RCX: 42215896cd52ea00 RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 RBP: 1ffff1100e907d96 R08: ffffffff816aa79d R09: fffff520002bece5 R10: fffff520002bece5 R11: 1ffff920002bece4 R12: ffff888021fd2000 R13: ffff88807483ecb0 R14: 0000000000000001 R15: ffff88807483e740 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555569ba628 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_es_remove_extent+0x1ab/0x260 fs/ext4/extents_status.c:1461 mpage_release_unused_pages+0x24d/0xef0 fs/ext4/inode.c:1589 ext4_writepages+0x12eb/0x3be0 fs/ext4/inode.c:2852 do_writepages+0x3c3/0x680 mm/page-writeback.c:2469 __writeback_single_inode+0xd1/0x670 fs/fs-writeback.c:1587 writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1870 wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2044 wb_do_writeback fs/fs-writeback.c:2187 [inline] wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2227 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Above issue may happens as follows: ext4_da_write_begin ext4_create_inline_data ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA); __ext4_ioctl ext4_ext_migrate -> will lead to eh->eh_entries not zero, and set extent flag ext4_da_write_begin ext4_da_convert_inline_data_to_extent ext4_da_write_inline_data_begin ext4_da_map_blocks ext4_insert_delayed_block if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) if (!ext4_es_scan_clu(inode, &ext4_es_is_mapped, lblk)) ext4_clu_mapped(inode, EXT4_B2C(sbi, lblk)); -> will return 1 allocated = true; ext4_es_insert_delayed_block(inode, lblk, allocated); ext4_writepages mpage_map_and_submit_extent(handle, &mpd, &give_up_on_write); -> return -ENOSPC mpage_release_unused_pages(&mpd, give_up_on_write); -> give_up_on_write == 1 ext4_es_remove_extent ext4_da_release_space(inode, reserved); if (unlikely(to_free > ei->i_reserved_data_blocks)) -> to_free == 1 but ei->i_reserved_data_blocks == 0 -> then trigger warning as above To solve above issue, forbid inode do migrate which has inline data. Cc: stable@kernel.org Reported-by: syzbot+c740bb18df70ad00952e@syzkaller.appspotmail.com Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20221018022701.683489-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o --- fs/ext4/migrate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c index 0a220ec9862d..a19a9661646e 100644 --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -424,7 +424,8 @@ int ext4_ext_migrate(struct inode *inode) * already is extent-based, error out. */ if (!ext4_has_feature_extents(inode->i_sb) || - (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) || + ext4_has_inline_data(inode)) return -EINVAL; if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0) From 9f2a1d9fb33a2129a9ba29bc61d3f14adb28ddc2 Mon Sep 17 00:00:00 2001 From: Jason Yan Date: Tue, 25 Oct 2022 12:02:06 +0800 Subject: [PATCH 4/5] ext4: fix wrong return err in ext4_load_and_init_journal() The return value is wrong in ext4_load_and_init_journal(). The local variable 'err' need to be initialized before goto out. The original code in __ext4_fill_super() is fine because it has two return values 'ret' and 'err' and 'ret' is initialized as -EINVAL. After we factor out ext4_load_and_init_journal(), this code is broken. So fix it by directly returning -EINVAL in the error handler path. Cc: stable@kernel.org Fixes: 9c1dd22d7422 ("ext4: factor out ext4_load_and_init_journal()") Signed-off-by: Jason Yan Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20221025040206.3134773-1-yanaijie@huawei.com Signed-off-by: Theodore Ts'o --- fs/ext4/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d733db8a0b02..6ddebc9f1b90 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4886,7 +4886,7 @@ out: flush_work(&sbi->s_error_work); jbd2_journal_destroy(sbi->s_journal); sbi->s_journal = NULL; - return err; + return -EINVAL; } static int ext4_journal_data_mode_check(struct super_block *sb) From 0d043351e5baf3857f915367deba2a518b6a0809 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 5 Nov 2022 23:42:36 -0400 Subject: [PATCH 5/5] ext4: fix fortify warning in fs/ext4/fast_commit.c:1551 With the new fortify string system, rework the memcpy to avoid this warning: memcpy: detected field-spanning write (size 60) of single field "&raw_inode->i_generation" at fs/ext4/fast_commit.c:1551 (size 4) Cc: stable@kernel.org Fixes: 54d9469bc515 ("fortify: Add run-time WARN for cross-field memcpy()") Signed-off-by: Theodore Ts'o --- fs/ext4/fast_commit.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c index ef05bfa87798..0f6d0a80467d 100644 --- a/fs/ext4/fast_commit.c +++ b/fs/ext4/fast_commit.c @@ -1521,6 +1521,7 @@ static int ext4_fc_replay_inode(struct super_block *sb, struct ext4_fc_tl *tl, struct ext4_iloc iloc; int inode_len, ino, ret, tag = tl->fc_tag; struct ext4_extent_header *eh; + size_t off_gen = offsetof(struct ext4_inode, i_generation); memcpy(&fc_inode, val, sizeof(fc_inode)); @@ -1548,8 +1549,8 @@ static int ext4_fc_replay_inode(struct super_block *sb, struct ext4_fc_tl *tl, raw_inode = ext4_raw_inode(&iloc); memcpy(raw_inode, raw_fc_inode, offsetof(struct ext4_inode, i_block)); - memcpy(&raw_inode->i_generation, &raw_fc_inode->i_generation, - inode_len - offsetof(struct ext4_inode, i_generation)); + memcpy((u8 *)raw_inode + off_gen, (u8 *)raw_fc_inode + off_gen, + inode_len - off_gen); if (le32_to_cpu(raw_inode->i_flags) & EXT4_EXTENTS_FL) { eh = (struct ext4_extent_header *)(&raw_inode->i_block[0]); if (eh->eh_magic != EXT4_EXT_MAGIC) {