This is a note to let you know that I've just added the patch titled ext4: avoid potential extra brelse in setup_new_flex_group_blocks() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-avoid-potential-extra-brelse-in-setup_new_flex_group_blocks.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 9e4028935cca3f9ef9b6a90df9da6f1f94853536 Mon Sep 17 00:00:00 2001 From: Vasily Averin <vvs@xxxxxxxxxxxxx> Date: Sat, 3 Nov 2018 16:13:17 -0400 Subject: ext4: avoid potential extra brelse in setup_new_flex_group_blocks() From: Vasily Averin <vvs@xxxxxxxxxxxxx> commit 9e4028935cca3f9ef9b6a90df9da6f1f94853536 upstream. Currently bh is set to NULL only during first iteration of for cycle, then this pointer is not cleared after end of using. Therefore rollback after errors can lead to extra brelse(bh) call, decrements bh counter and later trigger an unexpected warning in __brelse() Patch moves brelse() calls in body of cycle to exclude requirement of brelse() call in rollback. Fixes: 33afdcc5402d ("ext4: add a function which sets up group blocks ...") Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Cc: stable@xxxxxxxxxx # 3.3+ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/resize.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -590,7 +590,6 @@ handle_bb: bh = bclean(handle, sb, block); if (IS_ERR(bh)) { err = PTR_ERR(bh); - bh = NULL; goto out; } overhead = ext4_group_overhead_blocks(sb, group); @@ -602,9 +601,9 @@ handle_bb: ext4_mark_bitmap_end(group_data[i].blocks_count, sb->s_blocksize * 8, bh->b_data); err = ext4_handle_dirty_metadata(handle, NULL, bh); + brelse(bh); if (err) goto out; - brelse(bh); handle_ib: if (bg_flags[i] & EXT4_BG_INODE_UNINIT) @@ -619,18 +618,16 @@ handle_ib: bh = bclean(handle, sb, block); if (IS_ERR(bh)) { err = PTR_ERR(bh); - bh = NULL; goto out; } ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8, bh->b_data); err = ext4_handle_dirty_metadata(handle, NULL, bh); + brelse(bh); if (err) goto out; - brelse(bh); } - bh = NULL; /* Mark group tables in block bitmap */ for (j = 0; j < GROUP_TABLE_COUNT; j++) { @@ -661,7 +658,6 @@ handle_ib: } out: - brelse(bh); err2 = ext4_journal_stop(handle); if (err2 && !err) err = err2; Patches currently in stable-queue which might be from vvs@xxxxxxxxxxxxx are queue-4.9/ext4-add-missing-brelse-add_new_gdb_meta_bg-s-error-path.patch queue-4.9/ext4-avoid-buffer-leak-in-ext4_orphan_add-after-prior-errors.patch queue-4.9/ext4-release-bs.bh-before-re-using-in-ext4_xattr_block_find.patch queue-4.9/ext4-fix-missing-cleanup-if-ext4_alloc_flex_bg_array-fails-while-resizing.patch queue-4.9/ext4-fix-buffer-leak-in-__ext4_read_dirblock-on-error-path.patch queue-4.9/ext4-fix-possible-inode-leak-in-the-retry-loop-of-ext4_resize_fs.patch queue-4.9/ext4-fix-possible-leak-of-sbi-s_group_desc_leak-in-error-path.patch queue-4.9/ext4-add-missing-brelse-in-set_flexbg_block_bitmap-s-error-path.patch queue-4.9/ext4-fix-buffer-leak-in-ext4_xattr_move_to_block-on-error-path.patch queue-4.9/ext4-avoid-potential-extra-brelse-in-setup_new_flex_group_blocks.patch queue-4.9/ext4-add-missing-brelse-update_backups-s-error-path.patch queue-4.9/ext4-avoid-possible-double-brelse-in-add_new_gdb-on-error-path.patch queue-4.9/ext4-fix-possible-leak-of-s_journal_flag_rwsem-in-error-path.patch