From 9638e1d6e79e8eb64b9f3f59e0db890369d30ff6 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sun, 29 Apr 2018 12:26:42 +0200 Subject: [PATCH] 4.16-stable patches added patches: ext4-fix-bitmap-position-validation.patch --- .../ext4-fix-bitmap-position-validation.patch | 80 +++++++++++++++++++ queue-4.16/series | 1 + 2 files changed, 81 insertions(+) create mode 100644 queue-4.16/ext4-fix-bitmap-position-validation.patch diff --git a/queue-4.16/ext4-fix-bitmap-position-validation.patch b/queue-4.16/ext4-fix-bitmap-position-validation.patch new file mode 100644 index 00000000000..895b371759b --- /dev/null +++ b/queue-4.16/ext4-fix-bitmap-position-validation.patch @@ -0,0 +1,80 @@ +From 22be37acce25d66ecf6403fc8f44df9c5ded2372 Mon Sep 17 00:00:00 2001 +From: Lukas Czerner +Date: Tue, 24 Apr 2018 11:31:44 -0400 +Subject: ext4: fix bitmap position validation + +From: Lukas Czerner + +commit 22be37acce25d66ecf6403fc8f44df9c5ded2372 upstream. + +Currently in ext4_valid_block_bitmap() we expect the bitmap to be +positioned anywhere between 0 and s_blocksize clusters, but that's +wrong because the bitmap can be placed anywhere in the block group. This +causes false positives when validating bitmaps on perfectly valid file +system layouts. Fix it by checking whether the bitmap is within the group +boundary. + +The problem can be reproduced using the following + +mkfs -t ext3 -E stride=256 /dev/vdb1 +mount /dev/vdb1 /mnt/test +cd /mnt/test +wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.16.3.tar.xz +tar xf linux-4.16.3.tar.xz + +This will result in the warnings in the logs + +EXT4-fs error (device vdb1): ext4_validate_block_bitmap:399: comm tar: bg 84: block 2774529: invalid block bitmap + +[ Changed slightly for clarity and to not drop a overflow test -- TYT ] + +Signed-off-by: Lukas Czerner +Signed-off-by: Theodore Ts'o +Reported-by: Ilya Dryomov +Fixes: 7dac4a1726a9 ("ext4: add validity checks for bitmap block numbers") +Cc: stable@vger.kernel.org +Signed-off-by: Greg Kroah-Hartman + +--- + fs/ext4/balloc.c | 9 +++++---- + 1 file changed, 5 insertions(+), 4 deletions(-) + +--- a/fs/ext4/balloc.c ++++ b/fs/ext4/balloc.c +@@ -321,6 +321,7 @@ static ext4_fsblk_t ext4_valid_block_bit + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_grpblk_t offset; + ext4_grpblk_t next_zero_bit; ++ ext4_grpblk_t max_bit = EXT4_CLUSTERS_PER_GROUP(sb); + ext4_fsblk_t blk; + ext4_fsblk_t group_first_block; + +@@ -338,7 +339,7 @@ static ext4_fsblk_t ext4_valid_block_bit + /* check whether block bitmap block number is set */ + blk = ext4_block_bitmap(sb, desc); + offset = blk - group_first_block; +- if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || ++ if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit || + !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) + /* bad block bitmap */ + return blk; +@@ -346,7 +347,7 @@ static ext4_fsblk_t ext4_valid_block_bit + /* check whether the inode bitmap block number is set */ + blk = ext4_inode_bitmap(sb, desc); + offset = blk - group_first_block; +- if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || ++ if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit || + !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) + /* bad block bitmap */ + return blk; +@@ -354,8 +355,8 @@ static ext4_fsblk_t ext4_valid_block_bit + /* check whether the inode table block number is set */ + blk = ext4_inode_table(sb, desc); + offset = blk - group_first_block; +- if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || +- EXT4_B2C(sbi, offset + sbi->s_itb_per_group) >= sb->s_blocksize) ++ if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit || ++ EXT4_B2C(sbi, offset + sbi->s_itb_per_group) >= max_bit) + return blk; + next_zero_bit = ext4_find_next_zero_bit(bh->b_data, + EXT4_B2C(sbi, offset + sbi->s_itb_per_group), diff --git a/queue-4.16/series b/queue-4.16/series index 3754981b393..57aeaaa34cc 100644 --- a/queue-4.16/series +++ b/queue-4.16/series @@ -2,3 +2,4 @@ ext4-prevent-right-shifting-extents-beyond-ext_max_blocks.patch ext4-set-h_journal-if-there-is-a-failure-starting-a-reserved-handle.patch ext4-add-module_softdep-to-ensure-crc32c-is-included-in-the-initramfs.patch ext4-add-validity-checks-for-bitmap-block-numbers.patch +ext4-fix-bitmap-position-validation.patch -- 2.47.3