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| author | Ritesh Harjani <riteshh@linux.ibm.com> | 2021-06-05 10:39:32 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-10-06 15:56:01 +0200 |
| commit | d11502fa26913f84883438c55fab0a8cb0d11474 (patch) | |
| tree | 204e2c1c4b846499ef9450e9ece31a6d301e02a8 /fs/ext4 | |
| parent | 7cea848678470daadbfdaa6a112b823c290f900c (diff) | |
ext4: fix loff_t overflow in ext4_max_bitmap_size()
commit 75ca6ad408f459f00b09a64f04c774559848c097 upstream.
We should use unsigned long long rather than loff_t to avoid
overflow in ext4_max_bitmap_size() for comparison before returning.
w/o this patch sbi->s_bitmap_maxbytes was becoming a negative
value due to overflow of upper_limit (with has_huge_files as true)
Below is a quick test to trigger it on a 64KB pagesize system.
sudo mkfs.ext4 -b 65536 -O ^has_extents,^64bit /dev/loop2
sudo mount /dev/loop2 /mnt
sudo echo "hello" > /mnt/hello -> This will error out with
"echo: write error: File too large"
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/594f409e2c543e90fd836b78188dfa5c575065ba.1622867594.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/super.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 099e4afa41e5..e5e896b6200a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3194,17 +3194,17 @@ static loff_t ext4_max_size(int blkbits, int has_huge_files) */ static loff_t ext4_max_bitmap_size(int bits, int has_huge_files) { - loff_t res = EXT4_NDIR_BLOCKS; + unsigned long long upper_limit, res = EXT4_NDIR_BLOCKS; int meta_blocks; - loff_t upper_limit; - /* This is calculated to be the largest file size for a dense, block + + /* + * This is calculated to be the largest file size for a dense, block * mapped file such that the file's total number of 512-byte sectors, * including data and all indirect blocks, does not exceed (2^48 - 1). * * __u32 i_blocks_lo and _u16 i_blocks_high represent the total * number of 512-byte sectors of the file. */ - if (!has_huge_files) { /* * !has_huge_files or implies that the inode i_block field @@ -3247,7 +3247,7 @@ static loff_t ext4_max_bitmap_size(int bits, int has_huge_files) if (res > MAX_LFS_FILESIZE) res = MAX_LFS_FILESIZE; - return res; + return (loff_t)res; } static ext4_fsblk_t descriptor_loc(struct super_block *sb, |