From 350acb8f51633145ca270a414e67010e8548260e Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 24 Mar 2018 11:01:43 -0400 Subject: [PATCH] add patch add-bitmap-block-validity-checks --- add-bitmap-block-validity-checks | 90 ++++++++++++++++++++++++++++++++++++++++ series | 2 + timestamps | 7 ++-- 3 files changed, 96 insertions(+), 3 deletions(-) create mode 100644 add-bitmap-block-validity-checks diff --git a/add-bitmap-block-validity-checks b/add-bitmap-block-validity-checks new file mode 100644 index 00000000..fa37d6c4 --- /dev/null +++ b/add-bitmap-block-validity-checks @@ -0,0 +1,90 @@ +ext4: add validity checks for bitmap block numbers + +https://bugzilla.kernel.org/show_bug.cgi?id=199181 + +Reported-by: Wen Xu +Signed-off-by: Theodore Ts'o +Cc: stable@vger.kernel.org +--- + fs/ext4/balloc.c | 16 ++++++++++++++-- + fs/ext4/ialloc.c | 7 +++++++ + 2 files changed, 21 insertions(+), 2 deletions(-) + +diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c +index f82c4966f4ce..a33d8fb1bf2a 100644 +--- a/fs/ext4/balloc.c ++++ b/fs/ext4/balloc.c +@@ -338,20 +338,25 @@ static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb, + /* check whether block bitmap block number is set */ + blk = ext4_block_bitmap(sb, desc); + offset = blk - group_first_block; +- if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) ++ if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || ++ !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) + /* bad block bitmap */ + return blk; + + /* check whether the inode bitmap block number is set */ + blk = ext4_inode_bitmap(sb, desc); + offset = blk - group_first_block; +- if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) ++ if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || ++ !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) + /* bad block bitmap */ + return blk; + + /* 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) ++ return blk; + next_zero_bit = ext4_find_next_zero_bit(bh->b_data, + EXT4_B2C(sbi, offset + sbi->s_itb_per_group), + EXT4_B2C(sbi, offset)); +@@ -417,6 +422,7 @@ struct buffer_head * + ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group) + { + struct ext4_group_desc *desc; ++ struct ext4_sb_info *sbi = EXT4_SB(sb); + struct buffer_head *bh; + ext4_fsblk_t bitmap_blk; + int err; +@@ -425,6 +431,12 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group) + if (!desc) + return ERR_PTR(-EFSCORRUPTED); + bitmap_blk = ext4_block_bitmap(sb, desc); ++ if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) || ++ (bitmap_blk >= ext4_blocks_count(sbi->s_es))) { ++ ext4_error(sb, "Invalid block bitmap block %llu in " ++ "block_group %u", bitmap_blk, block_group); ++ return ERR_PTR(-EFSCORRUPTED); ++ } + bh = sb_getblk(sb, bitmap_blk); + if (unlikely(!bh)) { + ext4_error(sb, "Cannot get buffer for block bitmap - " +diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c +index 3fa93665b4a3..df92e3ec9913 100644 +--- a/fs/ext4/ialloc.c ++++ b/fs/ext4/ialloc.c +@@ -122,6 +122,7 @@ static struct buffer_head * + ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) + { + struct ext4_group_desc *desc; ++ struct ext4_sb_info *sbi = EXT4_SB(sb); + struct buffer_head *bh = NULL; + ext4_fsblk_t bitmap_blk; + int err; +@@ -131,6 +132,12 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) + return ERR_PTR(-EFSCORRUPTED); + + bitmap_blk = ext4_inode_bitmap(sb, desc); ++ if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) || ++ (bitmap_blk >= ext4_blocks_count(sbi->s_es))) { ++ ext4_error(sb, "Invalid inode bitmap blk %llu in " ++ "block_group %u", bitmap_blk, block_group); ++ return ERR_PTR(-EFSCORRUPTED); ++ } + bh = sb_getblk(sb, bitmap_blk); + if (unlikely(!bh)) { + ext4_error(sb, "Cannot read inode bitmap - " diff --git a/series b/series index e60397b5..885f1bce 100644 --- a/series +++ b/series @@ -14,6 +14,8 @@ fix-offset-overflow-on-32bit-arches-iomap_begin remove-EXT4_STATE_DIOREAD_LOCK-flag dont-complain-about-incorrect-features-when-probing +add-bitmap-block-validity-checks + #################################################### # unstable patches #################################################### diff --git a/timestamps b/timestamps index 6f06a08e..a6bdd375 100755 --- a/timestamps +++ b/timestamps @@ -45,7 +45,8 @@ touch -d @1521733285 protect_disksize_update_in_direct_write_path touch -d @1521733499 update-i_disksize-if-direct-write-past-ondisk-size touch -d @1521733826 fix-offset-overflow-on-32bit-arches-iomap_begin touch -d @1521733930 remove-EXT4_STATE_DIOREAD_LOCK-flag -touch -d @1521733957 status touch -d @1521734340 dont-complain-about-incorrect-features-when-probing -touch -d @1521734376 series -touch -d @1521734379 timestamps +touch -d @1521870514 add-bitmap-block-validity-checks +touch -d @1521870514 status +touch -d @1521903689 series +touch -d @1521903694 timestamps -- 2.11.4.GIT