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authorChristoph Hellwig2020-05-05 17:43:15 +0200
committerTheodore Ts'o2020-05-19 15:03:37 -0400
commit959f7584512941a614113bfddb41b6812214169d (patch)
treeca83611f4644651ea3a8e7958a9d95f07a0a3b02 /fs/ext4
parent9f44eda19529b1c3eef50676dc54b8cd0aa86aa3 (diff)
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')
-rw-r--r--fs/ext4/extents.c31
-rw-r--r--fs/ext4/ioctl.c33
2 files changed, 33 insertions, 31 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index f2b577b315a0..2b4b94542e34 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4832,6 +4832,28 @@ 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)
{
@@ -4852,6 +4874,15 @@ 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,
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index bfc1281fc4cb..0746532ba463 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -733,29 +733,6 @@ static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa)
fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
}
-/* copied from fs/ioctl.c */
-static int fiemap_check_ranges(struct super_block *sb,
- u64 start, u64 len, u64 *new_len)
-{
- u64 maxbytes = (u64) sb->s_maxbytes;
-
- *new_len = len;
-
- 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)
- *new_len = maxbytes - start;
-
- return 0;
-}
-
/* So that the fiemap access checks can't overflow on 32 bit machines. */
#define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
@@ -765,8 +742,6 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg)
struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
struct fiemap_extent_info fieinfo = { 0, };
struct inode *inode = file_inode(filp);
- struct super_block *sb = inode->i_sb;
- u64 len;
int error;
if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
@@ -775,11 +750,6 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg)
if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
return -EINVAL;
- error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
- &len);
- if (error)
- return error;
-
fieinfo.fi_flags = fiemap.fm_flags;
fieinfo.fi_extents_max = fiemap.fm_extent_count;
fieinfo.fi_extents_start = ufiemap->fm_extents;
@@ -792,7 +762,8 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg)
if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
filemap_write_and_wait(inode->i_mapping);
- error = ext4_get_es_cache(inode, &fieinfo, fiemap.fm_start, len);
+ error = ext4_get_es_cache(inode, &fieinfo, fiemap.fm_start,
+ fiemap.fm_length);
fiemap.fm_flags = fieinfo.fi_flags;
fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))