bcachefs: fix overflow in fiemap

filefrag (and potentially other utilities that call fiemap) sometimes
pass ULONG_MAX as the length.  fiemap_prep clamps excessively large
lengths - but the calculation of end can overflow if it occurs before
calling fiemap_prep.  When this happens, filefrag assumes it has read to
the end and exits.

Signed-off-by: Reed Riley <reed@riley.engineer>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Reed Riley 2024-05-04 22:12:23 +00:00 committed by Kent Overstreet
parent db42549d40
commit 9a0ec04511
1 changed files with 1 additions and 1 deletions

View File

@ -964,7 +964,6 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
struct btree_iter iter;
struct bkey_s_c k;
struct bkey_buf cur, prev;
struct bpos end = POS(ei->v.i_ino, (start + len) >> 9);
unsigned offset_into_extent, sectors;
bool have_extent = false;
u32 snapshot;
@ -974,6 +973,7 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
if (ret)
return ret;
struct bpos end = POS(ei->v.i_ino, (start + len) >> 9);
if (start + len < start)
return -EINVAL;