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| author | Christoph Hellwig <hch@lst.de> | 2020-05-05 17:43:15 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-06-03 23:16:54 -0400 |
| commit | 328e24ae14aeb8ef624ec181e0d546b05c34f031 (patch) | |
| tree | 9eebbb580dca044c64ded7edb05fb00a7b33176b /fs/ext4/extents.c | |
| parent | 175efa81feb8405676e0136d97b10380179c92e0 (diff) | |
| download | linux-328e24ae14aeb8ef624ec181e0d546b05c34f031.tar.gz | |
ext4: fix fiemap size checks for bitmap files
Add an extra validation of the len parameter, as for ext4 some files
might have smaller file size limits than others. This also means the
redundant size check in ext4_ioctl_get_es_cache can go away, as all
size checking is done in the shared fiemap handler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200505154324.3226743-3-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index ce394706c61af..844773d3b64b5 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4862,6 +4862,28 @@ static const struct iomap_ops ext4_iomap_xattr_ops = { .iomap_begin = ext4_iomap_xattr_begin, }; +static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len) +{ + u64 maxbytes; + + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + maxbytes = inode->i_sb->s_maxbytes; + else + maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes; + + if (*len == 0) + return -EINVAL; + if (start > maxbytes) + return -EFBIG; + + /* + * Shrink request scope to what the fs can actually handle. + */ + if (*len > maxbytes || (maxbytes - *len) < start) + *len = maxbytes - start; + return 0; +} + static int _ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len, bool from_es_cache) { @@ -4882,6 +4904,15 @@ static int _ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, if (fiemap_check_flags(fieinfo, ext4_fiemap_flags)) return -EBADR; + /* + * For bitmap files the maximum size limit could be smaller than + * s_maxbytes, so check len here manually instead of just relying on the + * generic check. + */ + error = ext4_fiemap_check_ranges(inode, start, &len); + if (error) + return error; + if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR; error = iomap_fiemap(inode, fieinfo, start, len, |